US20050255208A1 - Food warming apparatus and method - Google Patents
Food warming apparatus and method Download PDFInfo
- Publication number
- US20050255208A1 US20050255208A1 US11/185,482 US18548205A US2005255208A1 US 20050255208 A1 US20050255208 A1 US 20050255208A1 US 18548205 A US18548205 A US 18548205A US 2005255208 A1 US2005255208 A1 US 2005255208A1
- Authority
- US
- United States
- Prior art keywords
- food
- holding
- cooked food
- radiant heat
- compartment
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 235000013305 food Nutrition 0.000 title claims abstract description 232
- 238000000034 method Methods 0.000 title claims abstract description 29
- 238000010792 warming Methods 0.000 title claims abstract description 7
- 238000010411 cooking Methods 0.000 claims abstract description 14
- 238000010438 heat treatment Methods 0.000 claims description 44
- 230000004913 activation Effects 0.000 claims description 9
- 230000007246 mechanism Effects 0.000 description 56
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 41
- 238000005192 partition Methods 0.000 description 9
- 235000013330 chicken meat Nutrition 0.000 description 8
- 241000287828 Gallus gallus Species 0.000 description 7
- 238000010276 construction Methods 0.000 description 4
- 230000007423 decrease Effects 0.000 description 4
- 238000001704 evaporation Methods 0.000 description 4
- 230000008020 evaporation Effects 0.000 description 4
- 239000000796 flavoring agent Substances 0.000 description 4
- 235000019634 flavors Nutrition 0.000 description 4
- 235000012020 french fries Nutrition 0.000 description 4
- 229910052782 aluminium Inorganic materials 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 230000008901 benefit Effects 0.000 description 2
- 230000015556 catabolic process Effects 0.000 description 2
- 238000006731 degradation reaction Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 235000013410 fast food Nutrition 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 230000003134 recirculating effect Effects 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- 238000009423 ventilation Methods 0.000 description 2
- 241000238557 Decapoda Species 0.000 description 1
- 235000013194 Lyophyllum decastes Nutrition 0.000 description 1
- 240000005856 Lyophyllum decastes Species 0.000 description 1
- 230000003213 activating effect Effects 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 235000015278 beef Nutrition 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 235000015228 chicken nuggets Nutrition 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000009849 deactivation Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 238000005485 electric heating Methods 0.000 description 1
- 229910052736 halogen Inorganic materials 0.000 description 1
- 150000002367 halogens Chemical class 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 1
- 239000000395 magnesium oxide Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
- 235000013573 potato product Nutrition 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 239000005341 toughened glass Substances 0.000 description 1
- 230000007306 turnover Effects 0.000 description 1
- 238000013022 venting Methods 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
- 235000021269 warm food Nutrition 0.000 description 1
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24C—DOMESTIC STOVES OR RANGES ; DETAILS OF DOMESTIC STOVES OR RANGES, OF GENERAL APPLICATION
- F24C7/00—Stoves or ranges heated by electric energy
- F24C7/08—Arrangement or mounting of control or safety devices
- F24C7/087—Arrangement or mounting of control or safety devices of electric circuits regulating heat
-
- A—HUMAN NECESSITIES
- A21—BAKING; EDIBLE DOUGHS
- A21B—BAKERS' OVENS; MACHINES OR EQUIPMENT FOR BAKING
- A21B1/00—Bakers' ovens
- A21B1/02—Bakers' ovens characterised by the heating arrangements
- A21B1/06—Ovens heated by radiators
- A21B1/22—Ovens heated by radiators by electric radiators
-
- A—HUMAN NECESSITIES
- A21—BAKING; EDIBLE DOUGHS
- A21B—BAKERS' OVENS; MACHINES OR EQUIPMENT FOR BAKING
- A21B2/00—Baking apparatus employing high-frequency or infrared heating
-
- A—HUMAN NECESSITIES
- A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
- A47J—KITCHEN EQUIPMENT; COFFEE MILLS; SPICE MILLS; APPARATUS FOR MAKING BEVERAGES
- A47J39/00—Heat-insulated warming chambers; Cupboards with heating arrangements for warming kitchen utensils
- A47J39/003—Heat-insulated warming chambers; Cupboards with heating arrangements for warming kitchen utensils with forced air circulation
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24C—DOMESTIC STOVES OR RANGES ; DETAILS OF DOMESTIC STOVES OR RANGES, OF GENERAL APPLICATION
- F24C7/00—Stoves or ranges heated by electric energy
- F24C7/06—Arrangement or mounting of electric heating elements
Definitions
- This invention relates generally to food service equipment and more particularly to equipment for maintaining foods at temperatures suitable for serving food.
- this invention is especially (but not exclusively) directed to food service equipment that uses infrared (IR) heaters to maintain pre-cooked food at proper temperatures before serving.
- IR infrared
- This type of equipment is referred to using such terms as holding oven, holding unit, and food warmer, and these terms are used interchangeably hereinafter.
- Such equipment is often used in, for example, the fast food service industry to heat food.
- short holding times e.g., twenty minutes or less
- rapid product quality degradation often limit the effectiveness of this technology for holding applications.
- different food products require different amounts of IR energy to be held in optimum condition. The quality of the food being held is affected in large part by the temperature and the air flow in the holding oven.
- IR holding devices are not adjustable to control the amount of IR energy delivered to the food being heated. Rather, the heat source is on full power all of the time, and the food is placed relatively far from the heat source to prevent overheating. As a result, the typical prior holding device requires a large amount of vertical space. This can present a problem in a situation where space is at a premium, as in a fast-food restaurant.
- U.S. Pat. Nos. 6,175,099, 6,262,394 and 6,541,739 assigned to Duke Manufacturing Co. of St. Louis, Mo. and incorporated herein by reference, are directed to a holding or cooking oven which is an improvement over prior designs and which has proven to be successful with various fried products.
- fried products such as hash browns, French fries, rotisserie chicken, deep-fried chicken and shrimp.
- a food warmer which is adapted for holding pre-cooked food longer without degradation of the quality of the product, including products having a crust which tends to become soggy or rubbery, such as fried potato products, fried chicken, and rotisserie chicken; the provision of such equipment which is more compact than conventional food warming equipment, thus requiring less space; the provision of such an oven which allows evaporative losses to be more closely controlled to enhance food quality; and a method of maintaining previously cooked food in an environment where the quality of the food is maintained at a high level for a longer period of time.
- one aspect of the present invention is directed to a method of preserving cooked food.
- the method comprises the steps of cooking food in a cooking appliance to provide pre-cooked food, placing the pre-cooked food in a holding compartment of a food warming apparatus for a duration of holding time, and heating the pre-cooked food in the holding compartment for at least a portion of the duration of holding time by delivering in a pre-programmed manner an amount of radiant heat to the pre-cooked food from a radiant heat source positioned above the pre-cooked food.
- the heating step comprises varying the amount of radiant heat delivered to the pre-cooked food to maintain the food at a selected holding temperature by delivering radiant heat to the pre-cooked food at a first level during a first phase of the duration of holding time and delivering radiant heat to the pre-cooked food at a second level during a second phase of the duration of holding time.
- the invention is directed to a method of controlling a food holding oven.
- the oven comprises a cabinet, a plurality of separate, thermally isolated holding compartments in the cabinet, a plurality of trays for containing pre-cooked food having been previously cooked in a cooking appliance, each compartment being adapted for removably receiving one tray per compartment, and heat sources above respective trays adapted for activation to emit radiant heat to the food in the trays to warm the food.
- the method of controlling the oven comprises setting a selected holding temperature for each compartment, setting a duration of holding time for each compartment, the duration of holding time comprising a duration of heated holding time, and varying the amount of radiant heat delivered to the pre-cooked food during a respective duration of heated holding time to maintain the food in a respective compartment at the selected holding temperature.
- FIG. 1 is a front elevation of an oven of the present invention equipped with heat sinks for receiving food-containing trays, auxiliary heat sources mounted above the heat sinks, and metallic covers for covering the trays (the trays being omitted from the view);
- FIG. 2 is an enlarged sectional view of a portion of FIG. 1 but showing a tray positioned in a respective heat sink below its cover;
- FIG. 3 is a perspective showing a heat sink, cover and auxiliary heat source
- FIG. 4 is a plan of a cover per se
- FIG. 5 is a front perspective view of another embodiment of an oven of the present invention equipped with compartments for receiving food-containing trays;
- FIG. 6 is a sectional view of a portion of the oven of FIG. 5 showing trays positioned in respective compartments below heat sources;
- FIG. 7 is a sectional view of a portion of the oven similar to FIG. 6 showing trays positioned in respective compartments below alternate heat sources;
- FIG. 8 is a sectional view of a portion of the oven similar to FIG. 6 showing trays positioned in respective compartments below alternate heat sources;
- FIG. 9 is a sectional view of a portion of the oven of FIG. 5 showing a ventilation system of the oven according to an embodiment of the invention.
- FIG. 10 is a perspective view of one embodiment of a tray used with the oven of FIG. 5 ;
- FIG. 11 is a schematic diagram of one embodiment of a control circuit of the oven of FIG. 5 ;
- FIG. 12 is a diagram of a time vs. temperature curve illustrating one mode of operation of the oven of FIG. 5 ;
- FIG. 13 is a time vs. heat source activation curve for the mode of operation depicted in FIG. 12 ;
- FIG. 14 is a diagram of a time vs. temperature curve illustrating a different mode of operation of the oven of FIG. 5 ;
- FIG. 15 is a time vs. heat source activation curve for the mode of operation depicted in FIG. 14 ;
- FIG. 16 is a perspective of a different embodiment of a holding oven of this invention.
- FIG. 17 is a front elevation of the holding oven of FIG. 16 ;
- FIG. 18 is a section on line 18 - 18 of FIG. 17 ;
- FIG. 19 is an enlarged portion of FIG. 17 with parts broken away to show the distance D 1 between the food in the oven and a heat source of the oven;
- FIG. 20 is a right-side elevation of the holding oven of FIG. 16 ;
- FIG. 21 is a section on line 21 - 21 of FIG. 20 ;
- FIG. 22A is a graph of a time v. holding temperature curve during an embodiment of a holding duration
- FIG. 22B is a graph of time v. radiant energy curve during the embodiment of FIG. 22A ;
- FIG. 23 is a schematic view of a holding oven of another embodiment
- FIG. 24 is a schematic view of a holding oven of still another embodiment.
- FIG. 25 is a schematic view of a holding oven of yet another embodiment.
- FIG. 1 illustrates one embodiment of a holding oven of the present invention, generally designated 1 , comprising a cabinet having an interior 12 comprising a plurality of tiers for removably receiving a plurality of trays, each generally designated 3 , the trays in each tier being disposed side-by-side.
- the oven has two tiers, an upper tier 5 and a lower tier 7 , each accommodating three trays. It is to be understood that the number of tiers and the number of trays in each tier may vary.
- the holding oven 1 has a top 9 , bottom 11 , sides 13 and 15 , and a shelf 17 extending from one side to the other generally midway of the top and bottom.
- the shelf 17 and top 9 define the upper tier 5 ; the bottom 11 and shelf 17 define the lower tier 7 .
- the oven has a front panel 19 and a corresponding rear panel (not shown) each having openings such as indicated at 21 for sliding each tray 3 either into or out of its respective tier front or rear.
- each tray 3 is generally rectangular in plan, having a bottom 23 , opposite side walls each designated 25 , and end walls each designated 27 .
- Each tray is disposed in its respective tier 5 , 7 in the oven 1 in a heat sink generally designated 29 extending from front to rear in the respective tier, being slidably disposed in its heat sink for being slidably withdrawn from or entered in the heat sink either front or rear through the respective opening 21 .
- Each heat sink 29 which is made of aluminum, for example, has a bottom 31 and side walls each designated 33 ( FIG. 2 ).
- the side walls 33 have outwardly (laterally) extending flanges 35 and rims 37 extending up from the outer margins of the flanges.
- Each heat sink constitutes a tray-receiving member for holding a single tray.
- An electrical resistance heating element generally designated 39 having a bottom component 41 contacting the bottom of the heat sink and upwardly extending side components 43 contacting the sides of each heat sink is provided for heating the heat sink and the tray 3 therein.
- Each heat sink 29 and associated heating element 39 constitutes the primary heating source for heating the respective tray 3 and its food content.
- an on-off electrical power control for all the heating elements 34 At 45 , are indicated temperature controls for the heating elements 39 in the upper and lower tiers.
- the bottom component 41 of each heating element 39 in the upper tier 5 seats on shelf 17
- the bottom component 41 of each heating element 39 in the lower tier 7 seats on the bottom 11 of the holding oven 1 .
- each heating element extends up to the flanges 35 of the respective heat sink 29 .
- each tray 3 has a rim 49 having an outwardly (laterally) directed upper part 51 with a downwardly extending angled lip 53 in sliding sealing engagement with the respective heat sink flange 35 .
- the rim defines the open top 32 of the tray 3 .
- a cover generally designated 55 is provided for the open top of each tray, each cover having a metallic portion 57 overlying the top of the respective tray. More specifically, the metallic portion 57 of each cover comprises a generally horizontal cross wall comprising a rectangular plate of anodized aluminum sheet, for example, having downturned flanges such as indicated at 59 at each side thereof and anodized metal angles 61 extending the length thereof on each side margin.
- One or more of the covers 55 is/are spaced above the rims 49 of respective trays 3 at a distance no greater than one inch, more preferably no greater than about 0.40 inch, and still more preferably no greater than about 0.30 in.
- One or more openings such as indicated at 63 is/are provided in at least one of the covers 55 for venting moisture from each tray having such an opening or openings.
- FIG. 4 shows a cover having sixteen openings 63 arranged in a pattern such as illustrated.
- the number and pattern may vary widely; the area of the one opening in a cover having one opening and the combined area of the openings in a cover having more than one opening is preferably less than about 25% of the area of the open top of the tray 3 it is covering, more preferably less than about 5% and even more preferably less than 1% thereof.
- the combined areas of the openings and the specific pattern of openings in a cover will vary depending on the type and quantity of food in the tray being covered. Whatever the circumstances, the size and pattern of the opening(s) can be selected to closely control the amount of moisture vented from the tray and thus optimize the conditions for maintaining food quality over an extended period of time.
- Each cover 55 is part of a system generally designated 65 for heating the food in the respective tray in addition to the primary heat source, e.g., the respective heat sink 29 and heating element 39 .
- This auxiliary heating system 65 comprises a heat source 67 for heating the metallic portion 57 of the respective cover 55 whereby the metallic portion is adapted to emit radiant heat to the food in the respective tray for additional warming of the food in the tray 3 .
- Each heat source 67 which is located over the respective cover 55 , comprises one electric heating element 69 or more disposed in a sheet metal housing 71 affixed to an interior surface of the oven or cabinet 1 .
- the heating element 69 is a commercial item, viz., a Chromalox electrical resistance heater element sold by Carlton Company of St. Louis, Mo.
- the housing 71 comprises a shallow pan of sheet metal such as aluminum having a rectangular bottom 73 , sides 75 , ends such as indicated at 77 and flanges 79 extending out from the top of the sides.
- the heating element 69 lies on the bottom 73 of the pan extending lengthwise thereof. It is suitably connected in an electrical circuit such that it is adapted to heat the respective cover 55 by heating the bottom 73 of the pan 71 with attendant emission of heat from the bottom of the pan to the cover. Terminals of the heating element for connection thereof in the aforesaid circuit are indicated at 81 and 83 .
- the pans 71 are affixed in the oven or cabinet with the bottom 73 of each pan 71 spaced above the respective cover 55 a distance less than 2.0 inches and more particularly less than about 1.0 inch.
- each heat source 67 ranges from 100-500 watts, for example, and each heat source 67 is operable to heat each cover 55 to a temperature which preferably ranges from 200° to 500° F.
- Pivoted locks for locking the covers 55 in the oven 1 are indicated at 85 .
- FIG. 5 illustrates a second embodiment of a holding oven of this invention, generally designated 101 , comprising a generally rectangular or box-shaped cabinet 102 .
- the cabinet 102 has a top 109 , a bottom 111 , opposite sides 113 and 115 , a front panel 119 and a corresponding rear panel (not shown).
- the cabinet 102 defines an interior, generally designated 112 , for removably receiving a plurality of trays, each generally designated 103 .
- the holding oven 101 has vertical partitions 126 and horizontal partitions 127 within the cabinet 102 dividing the interior 112 thereof into a plurality of separate, thermally isolated holding compartments 128 . It is to be understood that the number of vertical and horizontal partitions 126 and 127 (and thus the number of compartments 128 ) may vary. Preferably, the partitions 126 and 127 prevent the transfer of food flavors between the compartments 128 .
- the front panel 119 and rear panel contain openings, such as indicated at 121 , in communication with each compartment 128 .
- the openings 121 in the front panel 119 have corresponding openings (not shown) formed in the rear panel such that each compartment 128 extends from front to rear of the oven 101 and is adapted for removably receiving one of the trays 103 from either the front or the back of the holding oven 101 .
- the openings 121 are sized for sliding each tray 103 either into or out of the compartment 128 .
- the compartments 128 and corresponding openings 121 are arranged in several tiers of compartments.
- the holding oven has three horizontal tiers, an upper tier 132 , a middle tier 134 and a lower tier 136 .
- Each tier includes three compartments 128 , with each compartment accommodating an individual tray 103 .
- the number of tiers and the number of compartments in each tier may vary. In some embodiments, for example, it may be desirable to configure the holding oven 101 to have a single tier having two, three, or more compartments 128 .
- the entire cabinet 102 is fabricated of sheet metal material and a least the top 109 , the bottom 111 and the sides 113 and 115 are of a dual wall construction to insulate the interior 112 .
- the holding oven 101 includes a control mechanism, generally indicated at 140 , for controlling operation of the oven 101 .
- the control mechanism 140 has an operator input device, which in one embodiment, comprises a keypad, indicated by reference 142 , and a display, indicated by reference 144 , to selectively allow the operator to interact with the control mechanism to control the environment, such as the temperature and/or air flow, in each compartment 128 .
- the control mechanism may include a separate keypad for each compartment 128 .
- the operator input device can include dials, switches and the like known to those in the art.
- control mechanism 140 For example, rotatably mounted control dials mounted on the front panel 119 and movable in a push-and-turn fashion to any user-selected positions can permit operator input to the control mechanism 140 .
- the control mechanism 140 may also include associated indicator lights (not shown) to inform an operator of the status of a particular compartment 128 or the food within the compartment, such as whether the temperature in the compartment is at a desired temperature or whether the food in the compartment is approaching or has exceeded the desired hold time. Further operation of the control mechanism 140 will be described below.
- each compartment 128 has tray supports comprising, in one embodiment, inwardly (laterally) extending flanges 144 extending from the vertical partitions 126 at opposite sides of the compartment 128 .
- the flanges 144 are vertically spaced for supporting a tray 103 at different elevations in the compartment 128 .
- the compartments 128 in the holding oven 101 have different widths and/or heights to accommodate trays of different sizes. It is contemplated that the tray supports can have other forms, such as grooves or slots in the vertical partitions 126 .
- Heat sources 146 positioned above respective compartments 128 are adapted to emit radiant heat into the compartments directed at the trays 103 to warm food contained therein.
- Each heat source 146 can function as the primary heating source for heating the respective tray 103 and cooking its food content or maintaining an already cooked food near a selected temperature.
- the heat source (designated 146 A) is a quartz infrared heat source, but it will be understood that other heat sources may be used.
- FIG. 7 illustrates ceramic infrared heat sources 146 B and FIG. 8 illustrates resistance heating elements embedded in magnesium oxide 146 C. Alternatively, halogen infrared heat sources or other sources may be used.
- each heat source 146 ranges from between about 20 and 2,000 watts, desirably between about 25 and 1500 watts, preferably between about 30 and 1000 watts, more preferably between about 35 and 750 watts and even more preferably between about 40 and 600 watts. In one embodiment, each heat source 146 delivers about 400 watts of power. Additional means for heating the holding oven 101 other than heat sources 146 can be used without departing from the scope of this invention. Reference may be made to the aforementioned U.S. Pat. Nos. 6,175,099, 6,262,394 and 6,541,739, for further details relating to the construction of certain types of equipment used for heating the trays 103 and food contained therein.
- a panel 150 is positioned between each heat source 146 and its respective compartment 128 to prevent the trays 103 and their contents from contacting the heat sources.
- the panel 150 is a tempered glass cover that permits radiant energy produced by the heat source 146 to pass through into the compartment 128 .
- the panel is preferably made from transparent or semi-transparent glass.
- the panel 150 can be a radiant metallic plate.
- the heat source 146 is used to heat the panel 150 , and the panel then radiates heat to warm the contents of the tray 103 .
- a reflector 152 is positioned above the heat source 146 to radiate heat down toward the tray 103 below it.
- FIG. 9 illustrates an embodiment of the holding oven 101 having a forced air mechanism, indicated generally at 154 , for delivering recirculating air into the compartments 128 .
- the mechanism 154 comprises lower air ducting 160 , upper air ducting 162 , and a fan system 156 that moves air through the lower and upper air ducting air ducting.
- the fan system 156 circulates air in one direction along a flow path through the lower air ducting 160 , into the compartments 128 and then through the upper air ducting 162 and back to the fan system.
- the lower air ducting 160 conveys the forced air into the compartments 128 through openings 164 located in a floor 166 of the compartments 128 below the trays 103 .
- the fan system 156 moves air in the opposite direction through the upper air ducting 162 , down into the compartments via openings 168 , into the lower ducting 160 via openings 164 , and then back to the fan system.
- the number and pattern of openings 164 , 168 in the panels 150 and floor 166 may vary widely depending on the type of heat source 146 used in each compartment 128 and the type of food in the compartment.
- the size and/or speed of the fan system 156 and/or the number, pattern and/or size of the openings 164 , 168 associated with each compartment 128 can be varied to regulate the air flow around each tray 103 to provide optimum air flow for different food products.
- the number, size and/or pattern of the opening(s) 164 , 168 can be selected to closely control the amount of moisture vented from each compartment 128 and thus optimize the conditions for maintaining food quality over an extended period of time.
- An upper duct heat source 170 and a lower duct heat source 172 are positioned in the respective air ducting 162 , 160 for heating air flowing along the selected flow path.
- the upper and lower duct heat sources 170 , 172 heat the air that flows through the compartments so that, optionally, the food may also be warmed by convective heating.
- the duct heat sources 170 , 172 are commercially available items, e.g., Chromalox electrical resistance heater element sold by Carlton Company of St. Louis, Mo.
- the duct heat sources 170 , 172 may be used when additional heat is needed in the compartments 128 , such as when the initial temperature is low or a large quantity of food is placed in the compartments.
- temperature sensors 174 FIG.
- FIG. 9 illustrates a holding oven with a single tier and a single forced air mechanism 154 , but holding ovens 101 with multiple tiers can have separate fan systems with associated air ducting 160 , 162 for each tier within the scope of the invention.
- the air flow over the food in the tray 103 is controlled to enable an operator to control the amount of moisture that evaporates from the food.
- the air flow direction is from the bottom to the top, i.e., from the lower air ducting 160 through the compartment 128 and into the upper air ducting 162 , convection heat is applied to the food in the tray from below the tray, and infrared heat is applied from the heat sources 146 above the tray 103 .
- the food can be cooked or held with a combination of convection heat and infrared heat directed from above the tray 103 .
- air flow can be maintained continuously from one direction, e.g., always from bottom to top, throughout the cook/hold cycle. Alternately, the direction of the air flow can be reversed during the cook/hold cycle so that air flow is alternately directed from the bottom and from the top of the food product.
- the forced air mechanism 154 supplies air while the heat sources 146 are activated and is turned off when the heat sources are deactivated.
- each tray 103 is generally rectangular in plan, having a bottom 180 , opposite side walls each designated 182 , end walls each designated 184 , and an open top. As shown, each tray 103 has a rim 186 comprising a pair of laterally extending lips 190 adapted for sliding sealing engagement with the respective support flanges 144 in a compartment. One or more openings such as indicated at 194 is/are provided in at least one of the bottom 180 and/or the side walls 182 and end walls 184 for allowing air to circulate through the tray 103 to vent moisture from each tray.
- openings 194 in the tray 103 may be circular, oval, square or other shape and each opening may have an area of between about 0.1 and about 1.0 square inch. It is desirable that the combined area of the openings 194 in the tray is less than about 50% of the area of the open top of the tray 103 , preferably less than about 25% and more preferably less than about 10% thereof. Also, it is contemplated that different trays 103 within the oven 101 may have different patterns of openings 194 .
- the combined areas of the openings 194 and/or the specific pattern of openings in the tray 103 will vary depending on the type and quantity of food in the tray 103 . Whatever the circumstances, the size and pattern of the opening(s) 194 can be selected to closely control the amount of moisture evaporated from the tray 103 and thus optimize the conditions for maintaining food quality over an extended period of time.
- the control mechanism 140 is used to selectively control the environment, such as the temperature and/or air flow, in each compartment 128 of the holding oven 101 . As will be described more fully hereafter, the control mechanism 140 is operable to vary the amount of radiant heat as needed to maintain the food at a desired holding temperature to preserve the quality of the food for a longer period of time.
- the term “selected holding temperature” means either a single substantially constant temperature (e.g., 180° F.) or a range of temperatures (e.g., 160-180° F.).
- control mechanism comprises suitable timer and duty cycle controls to control the length of the duty cycle of each heat source 146 , the term “duty cycle” meaning the ratio of heat source on-time to heat source on-time plus heat source off-time.
- the control mechanism 140 uses a suitable microprocessor and appropriate software to control relays 198 ( FIG. 11 ) that activate the heat sources 146 , 170 and 172 and fans 156 .
- FIG. 11 is a simplified schematic of a portion of one embodiment of an oven control circuit, generally indicated at 196 , that is controlled by the control mechanism 140 .
- the circuit 196 operates the heat sources 146 in the multiple compartments 128 of the holding oven and the heat sources 170 , 172 in the upper and lower ducting 160 , 162 .
- the control mechanism 140 regulates the heat sources in the holding oven 101 by energizing conventional relays 198 . It is understood that the control mechanism 140 may independently operate the heat sources 146 in the compartments 128 , such that the heat source 146 for one compartment may be actuated while the corresponding heat source for another compartment is at a different level of activation or deactivated.
- control mechanism 140 may independently operate the upper and lower duct heat sources 170 , 172 such that neither, one or both heat sources in a flow path may be operating, and such that, for example, the top heat source may be operated in one tier while the bottom heat source may be operated in another tier.
- the control mechanism 140 can be programmed to control the heat sources 146 , 170 and 172 to adjust various parameters, such as, for example, the ambient hold time, the heated hold time, the total hold time, the percentage heater on time, the time base of the duty cycle, the cook or rethermalization time, and/or the temperature, as more fully described below.
- the control mechanism 140 controls operation of the heat sources 146 independent of one another so that the temperature in each compartment 128 may be independently controlled.
- the holding oven 101 will operate in at least two modes.
- a first “cool down and hold” mode the initial temperature of the food placed in the holding oven is higher than the desired holding temperature of the food, as is typically the case when the food has just been cooked in a cooking appliance (e.g., cooking or baking oven, frier, etc.) and then is transferred to the holding oven.
- a cooking appliance e.g., cooking or baking oven, frier, etc.
- control mechanism 140 is operable to maintain the heat source in a respective compartment 128 deactivated (or at a low level of activation) while the pre-cooked food in the compartment 128 cools down to the selected holding temperature during a duration of non-heated holding time, and for then controlling the heat source 146 in the compartment 128 to maintain the food in the compartment 128 at or near the selected holding temperature for a duration of heated holding time.
- the initial temperature of the pre-cooked food placed in the oven is lower than the desired holding temperature of the food, as where the food has been cooked and then refrigerated before placement in the holding oven.
- control mechanism 140 is operable to activate the heat source in the compartment 128 to raise the temperature in the compartment 128 to the selected holding temperature during a duration of rethermalizing holding time, and for then controlling the heat source 146 in the at least one compartment 128 to maintain the food in the compartment 128 at the selected holding temperature for the duration of heated holding time.
- the oven 1 of FIG. 1 can be used in a similar manner without departing from the scope of the invention.
- FIGS. 12 and 13 illustrate an example of the operation of the holding oven 101 in the first (cool down and hold) mode.
- FIG. 12 illustrates a time vs. temperature curve for a complete duration of holding time D for one compartment 128 of the oven 101
- FIG. 13 illustrates a time vs. activation curve for the heat source 146 of that same compartment during the holding time duration D.
- the time vs. temperature curve of FIG. 12 plots the temperature of the food product as a function of time.
- this curve can be different for each type of food product to be held in the oven 101 .
- a food product In a cool down and hold situation, a food product is typically cooked as by frying, grilling, baking, etc., in a cooking appliance until a desired high internal temperature, usually between about 170 and 210 degrees Fahrenheit (° F.), is achieved. After the food is cooked, the food product is placed in a tray 103 and inserted into compartment 128 in the oven 101 . Alternatively, the food can be placed in the oven without the use of a tray.
- the operator selects a desired holding temperature, indicated at T, which will be lower than the temperature Tc of the food initially placed in the compartment.
- the holding temperature T is the desired temperature for maintaining the pre-cooked food to preserve taste, appearance and/or other food quality.
- the operator also selects a duration of holding time D.
- the duration of holding time D is the total time the food is to be held in the oven 101 and maintained at a desired quality level.
- the control mechanism 140 can be programmed so that the operator need only select the type of food to be placed in the compartment and the control mechanism 140 automatically uses preselected settings for that type of food.
- the duration of holding time D may comprise an ambient hold time, i.e., a period of non-heated cool-down time such as indicated at B in FIG. 12 , during which time the food product is allowed to cool to the desired holding temperature T.
- heat source 146 is either in a deactivated state or a state in which it is delivering a relatively low quantity of radiant heat to the food so that the food product may cool down more rapidly than if the heat source was at full power.
- the food product is allowed to cool for the ambient hold time B until it reaches the desired hold temperature T as illustrated at point A.
- forced air flow from the forced air mechanism 154 can be used to more rapidly decrease the temperature.
- the food is held near the desired hold temperature to preserve food quality for a period of heated hold time, indicated at C, comprising the remaining portion of the holding time duration D.
- the heat source 146 may be operated in duty cycles to apply the appropriate amount of radiant heat to the food.
- the control mechanism 140 controls the heat sources 170 , 172 and the fan system 156 to maintain the internal food temperature at or near the desired hold temperature T during the heated hold time C.
- FIG. 13 illustrates an embodiment in which the heat source 146 is successively activated and deactivated in a controlled sequence or duty cycle, indicated at G, to maintain the temperature in the compartment 128 near the selected holding temperature T.
- each duty cycle G comprises a heating interval E during which time the heat source 146 is activated followed by a non-heating interval F during which time the heat source is deactivated.
- the time-base of the duty cycle G is the time required to complete one cycle of activation and deactivation of the heat source 146 as shown in FIG. 13 .
- the time-base of the duty cycle G and the percent on time of the heat source 146 maintains the actual temperature within the compartment 128 within at least about 15 degrees of the desired temperature, preferably within at least about 10 degrees, more preferably within about 5 degrees, and even more preferably within about 2 degrees of the desired temperature.
- the operator is able to set various parameters using the keypad 142 or other input device of the control mechanism 140 , such as the ambient hold time delay B, the heating interval E, the time-base of the duty cycle G, and/or total hold time D. These parameters can be selected by the operator or preset for the type of food product in the compartment 128 so that the operator need only select the proper food product.
- the control mechanism 140 in an oven 101 having more than one compartment 128 can control the duty cycle of the heat source 146 in each compartment to maintain the temperatures in the compartments at different levels.
- forced air flow from the forced air mechanism 154 conveys convective heating air into the compartments 128 at locations below the trays 103 for flow in a generally upward direction toward the trays 103 .
- the ventilation system conveys heating air into the compartments 128 at locations above the trays 103 for flow in a generally downward direction toward the trays 103 .
- the fan system 156 can be operated such that heating air is circulated through the compartments 128 in one direction and then the direction of air flow is reversed to circulate heating air through the compartments 128 in the opposite direction.
- the operator is able to select the duration that the fan system 156 circulates air through the compartments 128 .
- the forced air mechanism 154 operates in a controlled sequence during the duty cycle G such that the fan system 156 is activated when the heat sources 146 are activated and is deactivated when the heat sources are deactivated.
- the fan system 156 can be continuously activated for the duration of the total hold time D or can be activated so that the fan system is on a desired percentage of the duty cycle G independent of the heat sources.
- the fan system 156 is activated a suitable percentage of the time to control the evaporation of moisture from the food in the compartment 128 .
- the percentage of time the fan system 156 is activated desirably depends on the type and/or the amount of food placed in the compartment 128 .
- the percentage of time the fan system 156 is activated and the direction of air flow can be selected by the operator or preset for the type of food product in the compartment 128 so that the operator need only select the proper food product.
- the vertical position of at least one tray 103 in a respective compartment 128 may be varied.
- FIGS. 14 and 15 illustrate an example of the operation of the oven 101 in the second (heat up and hold or rethermalizing) mode.
- FIG. 14 illustrates a time vs. temperature curve for a complete hold cycle D for one compartment 128 of the oven 101
- FIG. 15 illustrates a time vs. activation curve for the heat source 146 of that same compartment during the hold cycle D.
- the time vs. temperature curve of FIG. 14 plots the temperature of the food product as a function of time.
- this curve can be different for each type of food product to be held in the oven 101 .
- the oven 101 is used to raise the temperature of a food product to a selected temperature and hold the food product at the selected temperature.
- a tray 103 containing a food product at an initial temperature T 1 is placed into the compartment 128 .
- Tempoture T 1 may vary from a frozen or refrigerated temperature to ambient or above.
- the keypad 142 or other input device the operator selects a desired holding temperature T (which will be higher than the initial food temperature T I ), and a duration of holding time D.
- the control mechanism 140 can be programmed so that the operator need only select the type of food to be placed in the compartment and the control mechanism 140 automatically uses preselected settings for that type of food.
- control mechanism is operable to activate the heat source 146 to raise the temperature of the food product for a duration of heat-up or rethermalization time, indicated at I, the food reaching the holding temperature T at time H.
- the heat source 146 is then activated and deactivated during the heated holding time C for successive duty cycles G to maintain the food in the compartment 128 at the selected holding temperature T for the duration the total hold time D.
- the duration of the heated holding time C includes intervals of the duty cycle G when the heat source 146 is activated as indicated by E and intervals during which the heat source is deactivated as indicated by F as described above.
- the holding time (D) for fast service cooked foods such as chicken and french fries is substantially increased, and good texture and taste are maintained.
- controlling the rate of evaporation of moisture from chicken for example, precludes drying out and toughening of the chicken fibers and precludes the breading from becoming dry and greasy.
- french fries for example, development of a dry, rubbery texture as moisture is lost and the outer skin loses crispness is precluded.
- control mechanism 140 uses a duty-cycle system to control the amount of radiant heat delivered to the pre-cooked food by the heat sources.
- the percentage of heater on and off time is adjusted to vary the radiant energy as needed to maintain the food at the suitable holding temperature. It will be understood, however, that the control mechanism 140 can vary the amount of radiant energy delivered to the food in other ways.
- the heat sources 146 may be variable-power heaters operable to deliver radiant heat at multiple discrete energy levels or at an infinite number of levels between full-power and zero power (as by varying the voltage to the heaters), and the control mechanism 140 may operate to increase and decrease the radiant heat delivered by the heaters in a controlled, pre-programmed manner to maintain a particular food at its ideal holding temperature.
- control mechanism 140 can include one or more sensors and one or more appropriate feedback loops for each compartment or group of components of the holding oven.
- at least one sensor is used in each compartment to detect a characteristic indicative of the temperature of the food in the compartment, and the control mechanism is responsive to signals received from the at least one sensor to control the heat source 146 to vary the radiant heat delivered to the pre-cooked food to maintain it at a holding temperature appropriate for that food.
- the characteristic detected by the one or more sensors may be the temperature of the air in the compartment, or the temperature of a surface in the compartment, or the radiant IR energy emitted by the food in the compartment, or some other characteristic.
- the sensor may be a standard temperature sensor, or an IR emissions detector, or some other type of detector capable of detecting the aforesaid characteristic indicative of the temperature of the food in the compartment.
- FIGS. 16-21 show another embodiment of food warming apparatus of this invention, generally designated 201 .
- the apparatus comprises a cabinet 203 having two horizontal tiers of compartments, two compartments per tier (each compartment being designated 207 ).
- the number of tiers can vary from one to any number more than one, and that the number of compartments 207 in each tier may vary from one to any number more than one.
- each compartment is sized to receive a single tray T, but it will be understood that each compartment 207 may be sized to receive more than one tray, or that some compartments may be sized to receive one tray and other compartments more than one tray.
- food is placed in one or more compartments 207 without the use of a tray.
- the cabinet 203 has front and back panels 211 , 213 with openings 215 aligned with the compartments 207 in the cabinet to allow food (either in or out of trays T) to be placed into the compartments and removed from the compartments from both ends of the compartments.
- the cabinet also has a bottom wall 221 , side walls 223 , a top wall 225 , a vertical partition or divider 227 extending between the top and bottom walls of the cabinet to separate the two compartments 207 in each tier, and a horizontal partition or divider 231 extending between the side walls 223 to separate the compartments in the upper tier from the compartments in the lower tier.
- the interior of the cabinet is divided into a plurality of separate, thermally isolated holding compartments 207 , and each compartment is completely enclosed on opposite sides, top and bottom so that food flavors are prevented (or at least inhibited) from transferring between compartments.
- Suitable thermal insulation (not shown) is provided adjacent the walls of each compartment 207 .
- each compartment 207 has a heat source 235 for emitting radiant heat down on pre-cooked food in the compartment.
- this heat source 225 may comprise one or more IR heat lamps or the like, each mounted by a suitable fixture adjacent to the top wall of the compartment.
- a reflector 241 is provided in each compartment 207 over the best source 235 for reflecting radiant heat in a generally downward direction through a cover panel 245 of suitable material capable of transmitting the heat (e.g., glass).
- the food in the compartment 207 is positioned a distance D 1 below the heat source 235 , as shown in FIG. 19 .
- Distance D 1 is desirably relatively small to reduce or minimize the size (e.g., vertical height) of the cabinet 203 .
- distance D 1 is less than 12 in.; in another it is less than 11 in.; in another it is less than 10 in.; in another it is less than 9 in.; in another it is less than 8 in.; in another it is less than 7 in.; in another it is less than 6 in.; in another it is less than 5 in.; in another it is less than 4 in.; in another it is less than 3 in.; in another it is less than 2 in.; in another it is less than 1 in.; and in another it less than 0.5 in.
- distance D 1 may be in the range of 0.25 in. to 10 in., or in the range of 0.25 in. to 8 in., or in the range of 0.25 in.
- each tray T is supported by supports 247 in a respective compartment 207 at an elevation where the bottom of the tray is spaced above the floor of the compartment a suitable distance D 2 .
- Distance D 2 may be in the range of 0-12 in., and more preferably 0.5-1.0 in.
- the food may be placed on the floor of the compartment.
- the heat sources 235 in the cabinet 203 are controlled by a suitable control mechanism 251 , similar to the control mechanism 140 described above, which can be used to operate each heat source 235 independently of the other heat sources to deliver varying amounts of radiant energy to the food in a respective compartment. In this manner, the amount of radiant energy delivered to the food in a compartment 207 can be closely controlled to maintain the food at an appropriate holding temperature for that particular food, as described above. Also, because the amount of radiant heat delivered to the food is varied as a function of time, the heat source 235 in each compartment 207 can be placed much closer to the food (e.g., distance D 1 in FIG. 19 , discussed above) which has the desirable advantage of reducing the size of the cabinet 203 .
- the heat source is energized to deliver full power all of the time.
- the heat source must be positioned relatively far from the food (e.g., 12 in. or more).
- control mechanism 251 is programmed for different types of food, so that after food has been placed in a particular compartment 207 , an operator simply selects that type of food from a suitable menu on a display (not shown) on the cabinet. The control mechanism then automatically selects the appropriate heating protocol for the food selected, including one or more of the following: the ideal holding temperature for the food selected; the duration of holding time (“holding duration”); and the manner in which the heat source in each compartment is to be varied to maintain the food at the desired holding temperature (e.g., percent on time during each duty cycle, if duty cycles are used).
- the control 251 also includes a timer which times out the holding duration, and a display 255 which shows the time remaining until the end of holding duration.
- the control mechanism 251 may also include a visual and/or audible alarm for alerting an operator at a predetermined time before the end of the holding duration, so that steps can be taken to start cooking a fresh batch or batches of additional food. (At the end of a holding duration, any food remaining in the compartments 207 is typically disposed of and replaced by freshly cooked food.)
- an important aspect of this invention is the ability of the control mechanism 251 to vary the amount of radiant heat delivered by the heat source in each compartment 207 to the pre-cooked food in the compartment.
- pre-cooked food introduced into the compartment be allowed to cool down as quickly as possible to the desired holding temperature, and that the food be held relatively constant at the desired holding temperature using a minimum of power to the heat source 235 .
- the graphs in FIGS. 22A and 22B illustrate this concept.
- FIG. 22A graphs time v. temperature in one compartment 207 .
- Pre-cooked food introduced into the compartment at time T 0 cools down to the desired holding temperature at time T 1 . Thereafter, the food is substantially maintained at the holding temperature for the remainder of the holding duration D.
- 22B is a graph of time v. the radiant energy delivered by the heat source 235 to the food.
- the heat source is operated at a first relatively low level (where the heater is either off or delivering radiant heat at low level of energy or power) during a first phase P 1 from time T 0 to time T 1 , so that little or no radiant energy is delivered to the food.
- the temperature of the food declines relatively rapidly toward ambient temperature.
- the control mechanism 251 causes the heat source 235 in the compartment 207 to deliver radiant heat at a second higher level (e.g., 70% of maximum) to stop the decline in temperature of the food and hold it at about the desired holding temperature during a second phase P 2 from time T 1 to time T 2 .
- a second higher level e.g. 70% of maximum
- the control mechanism 251 causes the heat source 235 to reduce the amount of radiant heat delivered to the food to a third level (e.g., 30% maximum) sufficient to maintain the food at the desired holding temperature during a third phase P 3 from time T 2 until the end of the holding period at time T 3 .
- FIG. 23 shows another embodiment of a holding oven of this invention, generally designated 301 .
- the oven is similar to those described above except that the cabinet of the unit has only one compartment.
- food is not placed in a tray, but rather on the bottom wall 307 or other supporting surface in the compartment, and the heat source 311 is closely spaced above the food to heat the food and maintain it at the desired holding temperature.
- the spacing D 1 between the food and the IR heat source is relatively small (as discussed above) to reduce the overall height dimension of the oven 301 .
- the heat source 311 is controlled by a control mechanism 140 , 251 of the type described above.
- FIG. 24 shows a holding oven, generally designated 401 , which is similar to the oven shown in FIG. 23 .
- the single compartment 403 of the oven is sized to hold multiple trays T. All other aspects of the oven, including the heat source and control mechanism, are the same.
- FIG. 25 shows a holding oven, generally designated 501 , which is similar to the oven shown in FIG. 24 except that the oven is divided into three compartments 503 , each of which is capable of receiving food placed on the bottom wall or other supporting surface in the compartment. Partitions 507 between the compartments prevent or at least inhibit the transfer of food flavors between adjacent compartments.
- Each compartment 503 has its own heat source 511 which is spaced relatively closely to the bottom wall of the compartment to maintain the distance between the food and the heat source within the ranges (e.g., distance D 1 ) described above.
- the heat sources 511 are controlled by a control mechanism similar to the control mechanism 140 , 251 described above.
Abstract
A method of preserving cooked food. Food is cooked in a cooking appliance to provide pre-cooked food and placed in a holding compartment of a food warming apparatus for a duration of holding time. The pre-cooked food is heated in the holding compartment for at least a portion of the duration of holding time by delivering in a pre-programmed manner an amount of radiant heat to the pre-cooked food from a radiant heat source positioned above the pre-cooked food. The amount of radiant heat delivered to the pre-cooked food is varied to maintain the food at a selected holding temperature by delivering radiant heat to the pre-cooked food at a first level during a first phase of the duration of holding time and delivering radiant heat to the pre-cooked food at a second level during a second phase of the duration of holding time.
Description
- This application is a divisional of pending U.S. application Ser. No. 10/680,626, filed Oct. 7, 2003, which is a continuation-in-part of pending U.S. application Ser. No. 10/611,295, filed Jul. 1, 2003, which claims the benefit of U.S. Provisional Application No. 60/394,841, filed Jul. 10, 2002, titled HOLDING OR COOKING OVEN.
- This invention relates generally to food service equipment and more particularly to equipment for maintaining foods at temperatures suitable for serving food.
- In one embodiment, this invention is especially (but not exclusively) directed to food service equipment that uses infrared (IR) heaters to maintain pre-cooked food at proper temperatures before serving. This type of equipment is referred to using such terms as holding oven, holding unit, and food warmer, and these terms are used interchangeably hereinafter. Such equipment is often used in, for example, the fast food service industry to heat food. However, such equipment has certain disadvantages. For example, short holding times (e.g., twenty minutes or less) and rapid product quality degradation often limit the effectiveness of this technology for holding applications. Additionally, different food products require different amounts of IR energy to be held in optimum condition. The quality of the food being held is affected in large part by the temperature and the air flow in the holding oven. As the food loses moisture due to evaporation, flavor is lost. This affects the texture and taste of the product. For example, chicken meat fibers will dry out and become tough, while the breading will become dry and greasy. French fries will develop a dry, rubbery texture as moisture is lost and the outer skin loses its crispness.
- Conventional IR holding devices are not adjustable to control the amount of IR energy delivered to the food being heated. Rather, the heat source is on full power all of the time, and the food is placed relatively far from the heat source to prevent overheating. As a result, the typical prior holding device requires a large amount of vertical space. This can present a problem in a situation where space is at a premium, as in a fast-food restaurant.
- U.S. Pat. Nos. 6,175,099, 6,262,394 and 6,541,739, assigned to Duke Manufacturing Co. of St. Louis, Mo. and incorporated herein by reference, are directed to a holding or cooking oven which is an improvement over prior designs and which has proven to be successful with various fried products. However, there is still a need for a technology that extends the holding time and quality of food products, especially fried products such as hash browns, French fries, rotisserie chicken, deep-fried chicken and shrimp.
- Among the several objects of this invention will be noted the provision of food service equipment, e.g., a food warmer, which is adapted for holding pre-cooked food longer without degradation of the quality of the product, including products having a crust which tends to become soggy or rubbery, such as fried potato products, fried chicken, and rotisserie chicken; the provision of such equipment which is more compact than conventional food warming equipment, thus requiring less space; the provision of such an oven which allows evaporative losses to be more closely controlled to enhance food quality; and a method of maintaining previously cooked food in an environment where the quality of the food is maintained at a high level for a longer period of time.
- In general, one aspect of the present invention is directed to a method of preserving cooked food. The method comprises the steps of cooking food in a cooking appliance to provide pre-cooked food, placing the pre-cooked food in a holding compartment of a food warming apparatus for a duration of holding time, and heating the pre-cooked food in the holding compartment for at least a portion of the duration of holding time by delivering in a pre-programmed manner an amount of radiant heat to the pre-cooked food from a radiant heat source positioned above the pre-cooked food. The heating step comprises varying the amount of radiant heat delivered to the pre-cooked food to maintain the food at a selected holding temperature by delivering radiant heat to the pre-cooked food at a first level during a first phase of the duration of holding time and delivering radiant heat to the pre-cooked food at a second level during a second phase of the duration of holding time.
- In yet another aspect, the invention is directed to a method of controlling a food holding oven. The oven comprises a cabinet, a plurality of separate, thermally isolated holding compartments in the cabinet, a plurality of trays for containing pre-cooked food having been previously cooked in a cooking appliance, each compartment being adapted for removably receiving one tray per compartment, and heat sources above respective trays adapted for activation to emit radiant heat to the food in the trays to warm the food. The method of controlling the oven comprises setting a selected holding temperature for each compartment, setting a duration of holding time for each compartment, the duration of holding time comprising a duration of heated holding time, and varying the amount of radiant heat delivered to the pre-cooked food during a respective duration of heated holding time to maintain the food in a respective compartment at the selected holding temperature.
- Other objects and features will be in part apparent and in part pointed out hereinafter.
-
FIG. 1 is a front elevation of an oven of the present invention equipped with heat sinks for receiving food-containing trays, auxiliary heat sources mounted above the heat sinks, and metallic covers for covering the trays (the trays being omitted from the view); -
FIG. 2 is an enlarged sectional view of a portion ofFIG. 1 but showing a tray positioned in a respective heat sink below its cover; -
FIG. 3 is a perspective showing a heat sink, cover and auxiliary heat source; -
FIG. 4 is a plan of a cover per se; -
FIG. 5 is a front perspective view of another embodiment of an oven of the present invention equipped with compartments for receiving food-containing trays; -
FIG. 6 is a sectional view of a portion of the oven ofFIG. 5 showing trays positioned in respective compartments below heat sources; -
FIG. 7 is a sectional view of a portion of the oven similar toFIG. 6 showing trays positioned in respective compartments below alternate heat sources; -
FIG. 8 is a sectional view of a portion of the oven similar toFIG. 6 showing trays positioned in respective compartments below alternate heat sources; -
FIG. 9 is a sectional view of a portion of the oven ofFIG. 5 showing a ventilation system of the oven according to an embodiment of the invention; -
FIG. 10 is a perspective view of one embodiment of a tray used with the oven ofFIG. 5 ; -
FIG. 11 is a schematic diagram of one embodiment of a control circuit of the oven ofFIG. 5 ; -
FIG. 12 is a diagram of a time vs. temperature curve illustrating one mode of operation of the oven ofFIG. 5 ; -
FIG. 13 is a time vs. heat source activation curve for the mode of operation depicted inFIG. 12 ; -
FIG. 14 is a diagram of a time vs. temperature curve illustrating a different mode of operation of the oven ofFIG. 5 ; -
FIG. 15 is a time vs. heat source activation curve for the mode of operation depicted inFIG. 14 ; -
FIG. 16 is a perspective of a different embodiment of a holding oven of this invention; -
FIG. 17 is a front elevation of the holding oven ofFIG. 16 ; -
FIG. 18 is a section on line 18-18 ofFIG. 17 ; -
FIG. 19 is an enlarged portion ofFIG. 17 with parts broken away to show the distance D1 between the food in the oven and a heat source of the oven; -
FIG. 20 is a right-side elevation of the holding oven ofFIG. 16 ; -
FIG. 21 is a section on line 21-21 ofFIG. 20 ; -
FIG. 22A is a graph of a time v. holding temperature curve during an embodiment of a holding duration; -
FIG. 22B is a graph of time v. radiant energy curve during the embodiment ofFIG. 22A ; -
FIG. 23 is a schematic view of a holding oven of another embodiment; -
FIG. 24 is a schematic view of a holding oven of still another embodiment; and -
FIG. 25 is a schematic view of a holding oven of yet another embodiment. - Corresponding parts are designated by corresponding reference numbers throughout the drawings.
-
FIG. 1 illustrates one embodiment of a holding oven of the present invention, generally designated 1, comprising a cabinet having an interior 12 comprising a plurality of tiers for removably receiving a plurality of trays, each generally designated 3, the trays in each tier being disposed side-by-side. As shown, the oven has two tiers, anupper tier 5 and alower tier 7, each accommodating three trays. It is to be understood that the number of tiers and the number of trays in each tier may vary. - The holding
oven 1 has a top 9, bottom 11, sides 13 and 15, and ashelf 17 extending from one side to the other generally midway of the top and bottom. Theshelf 17 and top 9 define theupper tier 5; the bottom 11 andshelf 17 define thelower tier 7. The oven has afront panel 19 and a corresponding rear panel (not shown) each having openings such as indicated at 21 for sliding eachtray 3 either into or out of its respective tier front or rear. - In one embodiment, each
tray 3 is generally rectangular in plan, having a bottom 23, opposite side walls each designated 25, and end walls each designated 27. Each tray is disposed in itsrespective tier oven 1 in a heat sink generally designated 29 extending from front to rear in the respective tier, being slidably disposed in its heat sink for being slidably withdrawn from or entered in the heat sink either front or rear through therespective opening 21. Eachheat sink 29, which is made of aluminum, for example, has a bottom 31 and side walls each designated 33 (FIG. 2 ). Theside walls 33 have outwardly (laterally) extendingflanges 35 andrims 37 extending up from the outer margins of the flanges. Each heat sink constitutes a tray-receiving member for holding a single tray. An electrical resistance heating element generally designated 39 having abottom component 41 contacting the bottom of the heat sink and upwardly extendingside components 43 contacting the sides of each heat sink is provided for heating the heat sink and thetray 3 therein. Eachheat sink 29 and associatedheating element 39 constitutes the primary heating source for heating therespective tray 3 and its food content. At 45 is indicated an on-off electrical power control for all the heating elements 34. At 47, are indicated temperature controls for theheating elements 39 in the upper and lower tiers. Thebottom component 41 of eachheating element 39 in theupper tier 5 seats onshelf 17, thebottom component 41 of eachheating element 39 in thelower tier 7 seats on the bottom 11 of the holdingoven 1. Thesides 43 of each heating element extend up to theflanges 35 of therespective heat sink 29. Reference may be made to U.S. Pat. Nos. 6,175,099, 6,262,394 and 6,541,739, incorporated herein by reference, assigned to Duke Manufacturing Co. of St. Louis, Mo., for further details relating to the construction of theheat sink 29 and associated equipment. - Primary heating sources other than the heat sinks 29 and associated
heating elements 39 can be used without departing from the scope of this invention. - In the preferred embodiment, each
tray 3 has arim 49 having an outwardly (laterally) directedupper part 51 with a downwardly extendingangled lip 53 in sliding sealing engagement with the respectiveheat sink flange 35. The rim defines the open top 32 of thetray 3. A cover generally designated 55 is provided for the open top of each tray, each cover having ametallic portion 57 overlying the top of the respective tray. More specifically, themetallic portion 57 of each cover comprises a generally horizontal cross wall comprising a rectangular plate of anodized aluminum sheet, for example, having downturned flanges such as indicated at 59 at each side thereof and anodized metal angles 61 extending the length thereof on each side margin. The lower edges of thedownturned flanges 59 engage the top of theheat sink flanges 35. One or more of thecovers 55 is/are spaced above therims 49 ofrespective trays 3 at a distance no greater than one inch, more preferably no greater than about 0.40 inch, and still more preferably no greater than about 0.30 in. One or more openings such as indicated at 63 is/are provided in at least one of thecovers 55 for venting moisture from each tray having such an opening or openings.FIG. 4 shows a cover having sixteenopenings 63 arranged in a pattern such as illustrated. The number and pattern may vary widely; the area of the one opening in a cover having one opening and the combined area of the openings in a cover having more than one opening is preferably less than about 25% of the area of the open top of thetray 3 it is covering, more preferably less than about 5% and even more preferably less than 1% thereof. The combined areas of the openings and the specific pattern of openings in a cover will vary depending on the type and quantity of food in the tray being covered. Whatever the circumstances, the size and pattern of the opening(s) can be selected to closely control the amount of moisture vented from the tray and thus optimize the conditions for maintaining food quality over an extended period of time. - Each
cover 55 is part of a system generally designated 65 for heating the food in the respective tray in addition to the primary heat source, e.g., therespective heat sink 29 andheating element 39. Thisauxiliary heating system 65 comprises aheat source 67 for heating themetallic portion 57 of therespective cover 55 whereby the metallic portion is adapted to emit radiant heat to the food in the respective tray for additional warming of the food in thetray 3. Eachheat source 67, which is located over therespective cover 55, comprises oneelectric heating element 69 or more disposed in asheet metal housing 71 affixed to an interior surface of the oven orcabinet 1. In particular theheating element 69 is a commercial item, viz., a Chromalox electrical resistance heater element sold by Carlton Company of St. Louis, Mo. Thehousing 71 comprises a shallow pan of sheet metal such as aluminum having a rectangular bottom 73, sides 75, ends such as indicated at 77 andflanges 79 extending out from the top of the sides. - In one embodiment, the
heating element 69 lies on the bottom 73 of the pan extending lengthwise thereof. It is suitably connected in an electrical circuit such that it is adapted to heat therespective cover 55 by heating the bottom 73 of thepan 71 with attendant emission of heat from the bottom of the pan to the cover. Terminals of the heating element for connection thereof in the aforesaid circuit are indicated at 81 and 83. Thepans 71 are affixed in the oven or cabinet with the bottom 73 of eachpan 71 spaced above the respective cover 55 a distance less than 2.0 inches and more particularly less than about 1.0 inch. In one embodiment, the power delivered by eachheat source 67 to therespective cover 55 ranges from 100-500 watts, for example, and eachheat source 67 is operable to heat eachcover 55 to a temperature which preferably ranges from 200° to 500° F. Pivoted locks for locking thecovers 55 in theoven 1 are indicated at 85. -
FIG. 5 illustrates a second embodiment of a holding oven of this invention, generally designated 101, comprising a generally rectangular or box-shapedcabinet 102. Thecabinet 102 has a top 109, a bottom 111,opposite sides front panel 119 and a corresponding rear panel (not shown). Thecabinet 102 defines an interior, generally designated 112, for removably receiving a plurality of trays, each generally designated 103. The holdingoven 101 hasvertical partitions 126 andhorizontal partitions 127 within thecabinet 102 dividing theinterior 112 thereof into a plurality of separate, thermally isolated holding compartments 128. It is to be understood that the number of vertical andhorizontal partitions 126 and 127 (and thus the number of compartments 128) may vary. Preferably, thepartitions compartments 128. - The
front panel 119 and rear panel contain openings, such as indicated at 121, in communication with eachcompartment 128. In one embodiment, theopenings 121 in thefront panel 119 have corresponding openings (not shown) formed in the rear panel such that eachcompartment 128 extends from front to rear of theoven 101 and is adapted for removably receiving one of thetrays 103 from either the front or the back of the holdingoven 101. Theopenings 121 are sized for sliding eachtray 103 either into or out of thecompartment 128. - Preferably, the
compartments 128 andcorresponding openings 121 are arranged in several tiers of compartments. As shown inFIG. 5 , the holding oven has three horizontal tiers, anupper tier 132, amiddle tier 134 and alower tier 136. Each tier includes threecompartments 128, with each compartment accommodating anindividual tray 103. It is to be understood, however, that the number of tiers and the number of compartments in each tier may vary. In some embodiments, for example, it may be desirable to configure the holdingoven 101 to have a single tier having two, three, ormore compartments 128. Preferably, theentire cabinet 102 is fabricated of sheet metal material and a least the top 109, the bottom 111 and thesides - The holding
oven 101 includes a control mechanism, generally indicated at 140, for controlling operation of theoven 101. Preferably, thecontrol mechanism 140 has an operator input device, which in one embodiment, comprises a keypad, indicated byreference 142, and a display, indicated byreference 144, to selectively allow the operator to interact with the control mechanism to control the environment, such as the temperature and/or air flow, in eachcompartment 128. The control mechanism may include a separate keypad for eachcompartment 128. Alternately, the operator input device can include dials, switches and the like known to those in the art. For example, rotatably mounted control dials mounted on thefront panel 119 and movable in a push-and-turn fashion to any user-selected positions can permit operator input to thecontrol mechanism 140. Thecontrol mechanism 140 may also include associated indicator lights (not shown) to inform an operator of the status of aparticular compartment 128 or the food within the compartment, such as whether the temperature in the compartment is at a desired temperature or whether the food in the compartment is approaching or has exceeded the desired hold time. Further operation of thecontrol mechanism 140 will be described below. - Referring to
FIGS. 6-8 , eachcompartment 128 has tray supports comprising, in one embodiment, inwardly (laterally) extendingflanges 144 extending from thevertical partitions 126 at opposite sides of thecompartment 128. Theflanges 144 are vertically spaced for supporting atray 103 at different elevations in thecompartment 128. In one embodiment, thecompartments 128 in the holdingoven 101 have different widths and/or heights to accommodate trays of different sizes. It is contemplated that the tray supports can have other forms, such as grooves or slots in thevertical partitions 126. -
Heat sources 146 positioned aboverespective compartments 128 are adapted to emit radiant heat into the compartments directed at thetrays 103 to warm food contained therein. Eachheat source 146 can function as the primary heating source for heating therespective tray 103 and cooking its food content or maintaining an already cooked food near a selected temperature. In the embodiment shown inFIG. 6 , the heat source (designated 146A) is a quartz infrared heat source, but it will be understood that other heat sources may be used. For example,FIG. 7 illustrates ceramicinfrared heat sources 146B andFIG. 8 illustrates resistance heating elements embedded inmagnesium oxide 146C. Alternatively, halogen infrared heat sources or other sources may be used. The power delivered by eachheat source 146 ranges from between about 20 and 2,000 watts, desirably between about 25 and 1500 watts, preferably between about 30 and 1000 watts, more preferably between about 35 and 750 watts and even more preferably between about 40 and 600 watts. In one embodiment, eachheat source 146 delivers about 400 watts of power. Additional means for heating the holdingoven 101 other thanheat sources 146 can be used without departing from the scope of this invention. Reference may be made to the aforementioned U.S. Pat. Nos. 6,175,099, 6,262,394 and 6,541,739, for further details relating to the construction of certain types of equipment used for heating thetrays 103 and food contained therein. - In one embodiment, a
panel 150 is positioned between eachheat source 146 and itsrespective compartment 128 to prevent thetrays 103 and their contents from contacting the heat sources. In one embodiment, thepanel 150 is a tempered glass cover that permits radiant energy produced by theheat source 146 to pass through into thecompartment 128. In this embodiment, the panel is preferably made from transparent or semi-transparent glass. Alternately, thepanel 150 can be a radiant metallic plate. In this latter embodiment, theheat source 146 is used to heat thepanel 150, and the panel then radiates heat to warm the contents of thetray 103. Areflector 152 is positioned above theheat source 146 to radiate heat down toward thetray 103 below it. -
FIG. 9 illustrates an embodiment of the holdingoven 101 having a forced air mechanism, indicated generally at 154, for delivering recirculating air into thecompartments 128. Themechanism 154 compriseslower air ducting 160,upper air ducting 162, and afan system 156 that moves air through the lower and upper air ducting air ducting. In one mode of operation, thefan system 156 circulates air in one direction along a flow path through thelower air ducting 160, into thecompartments 128 and then through theupper air ducting 162 and back to the fan system. Thelower air ducting 160 conveys the forced air into thecompartments 128 throughopenings 164 located in afloor 166 of thecompartments 128 below thetrays 103. Air flows up from thecompartments 128 into theupper air ducting 162 through one ormore openings 168 in thepanels 150 above thetrays 103. In a second mode of operation, thefan system 156 moves air in the opposite direction through theupper air ducting 162, down into the compartments viaopenings 168, into thelower ducting 160 viaopenings 164, and then back to the fan system. - The number and pattern of
openings panels 150 andfloor 166 may vary widely depending on the type ofheat source 146 used in eachcompartment 128 and the type of food in the compartment. The size and/or speed of thefan system 156 and/or the number, pattern and/or size of theopenings compartment 128 can be varied to regulate the air flow around eachtray 103 to provide optimum air flow for different food products. Additionally, the number, size and/or pattern of the opening(s) 164, 168 can be selected to closely control the amount of moisture vented from eachcompartment 128 and thus optimize the conditions for maintaining food quality over an extended period of time. - An upper
duct heat source 170 and a lowerduct heat source 172 are positioned in therespective air ducting duct heat sources duct heat sources duct heat sources compartments 128, such as when the initial temperature is low or a large quantity of food is placed in the compartments. In one embodiment, temperature sensors 174 (FIG. 9 ), such as conventional resistive thermal detector type sensors known to those skilled in the art, may be positioned in each of thecompartments 128 or in theair ducting temperature sensors 174 provide feedback to thecontrol mechanism 140, for example, to supply an indication of the temperature to thedisplay 144, to control the operation of thefan system 156, or to provide indications to a warning system (not shown) that the temperature has exceeded a selected threshold. The forcedair mechanism 154 can also provide recirculating air for forced cooling of the food stored in thecompartment 128.FIG. 9 illustrates a holding oven with a single tier and a single forcedair mechanism 154, but holdingovens 101 with multiple tiers can have separate fan systems with associatedair ducting - The air flow over the food in the
tray 103 is controlled to enable an operator to control the amount of moisture that evaporates from the food. When the air flow direction is from the bottom to the top, i.e., from thelower air ducting 160 through thecompartment 128 and into theupper air ducting 162, convection heat is applied to the food in the tray from below the tray, and infrared heat is applied from theheat sources 146 above thetray 103. By changing the direction of air flow so that air flows from top to bottom, the food can be cooked or held with a combination of convection heat and infrared heat directed from above thetray 103. Depending on the food in the tray, air flow can be maintained continuously from one direction, e.g., always from bottom to top, throughout the cook/hold cycle. Alternately, the direction of the air flow can be reversed during the cook/hold cycle so that air flow is alternately directed from the bottom and from the top of the food product. In one embodiment, the forcedair mechanism 154 supplies air while theheat sources 146 are activated and is turned off when the heat sources are deactivated. - Referring now to
FIG. 10 , eachtray 103 is generally rectangular in plan, having a bottom 180, opposite side walls each designated 182, end walls each designated 184, and an open top. As shown, eachtray 103 has arim 186 comprising a pair of laterally extending lips 190 adapted for sliding sealing engagement with therespective support flanges 144 in a compartment. One or more openings such as indicated at 194 is/are provided in at least one of the bottom 180 and/or theside walls 182 and endwalls 184 for allowing air to circulate through thetray 103 to vent moisture from each tray.FIG. 10 shows a tray having sixteenopenings 194 in the bottom 180 and eachside wall 182 and 8openings 194 in eachend wall 184 arranged in a pattern such as illustrated. It is contemplated that the number, pattern and size ofopenings 194 may vary widely. For example, theopenings 194 in thetray 103 may be circular, oval, square or other shape and each opening may have an area of between about 0.1 and about 1.0 square inch. It is desirable that the combined area of theopenings 194 in the tray is less than about 50% of the area of the open top of thetray 103, preferably less than about 25% and more preferably less than about 10% thereof. Also, it is contemplated thatdifferent trays 103 within theoven 101 may have different patterns ofopenings 194. The combined areas of theopenings 194 and/or the specific pattern of openings in thetray 103 will vary depending on the type and quantity of food in thetray 103. Whatever the circumstances, the size and pattern of the opening(s) 194 can be selected to closely control the amount of moisture evaporated from thetray 103 and thus optimize the conditions for maintaining food quality over an extended period of time. - The
control mechanism 140 is used to selectively control the environment, such as the temperature and/or air flow, in eachcompartment 128 of the holdingoven 101. As will be described more fully hereafter, thecontrol mechanism 140 is operable to vary the amount of radiant heat as needed to maintain the food at a desired holding temperature to preserve the quality of the food for a longer period of time. As used herein, the term “selected holding temperature” means either a single substantially constant temperature (e.g., 180° F.) or a range of temperatures (e.g., 160-180° F.). In one embodiment, the control mechanism comprises suitable timer and duty cycle controls to control the length of the duty cycle of eachheat source 146, the term “duty cycle” meaning the ratio of heat source on-time to heat source on-time plus heat source off-time. Thecontrol mechanism 140 uses a suitable microprocessor and appropriate software to control relays 198 (FIG. 11 ) that activate theheat sources fans 156. -
FIG. 11 is a simplified schematic of a portion of one embodiment of an oven control circuit, generally indicated at 196, that is controlled by thecontrol mechanism 140. Thecircuit 196 operates theheat sources 146 in themultiple compartments 128 of the holding oven and theheat sources lower ducting control mechanism 140 regulates the heat sources in the holdingoven 101 by energizingconventional relays 198. It is understood that thecontrol mechanism 140 may independently operate theheat sources 146 in thecompartments 128, such that theheat source 146 for one compartment may be actuated while the corresponding heat source for another compartment is at a different level of activation or deactivated. Additionally, thecontrol mechanism 140 may independently operate the upper and lowerduct heat sources keypad 142 or other suitable operator input device, thecontrol mechanism 140 can be programmed to control theheat sources control mechanism 140 controls operation of theheat sources 146 independent of one another so that the temperature in eachcompartment 128 may be independently controlled. - Typically, the holding
oven 101 will operate in at least two modes. In a first “cool down and hold” mode, the initial temperature of the food placed in the holding oven is higher than the desired holding temperature of the food, as is typically the case when the food has just been cooked in a cooking appliance (e.g., cooking or baking oven, frier, etc.) and then is transferred to the holding oven. In this mode, thecontrol mechanism 140 is operable to maintain the heat source in arespective compartment 128 deactivated (or at a low level of activation) while the pre-cooked food in thecompartment 128 cools down to the selected holding temperature during a duration of non-heated holding time, and for then controlling theheat source 146 in thecompartment 128 to maintain the food in thecompartment 128 at or near the selected holding temperature for a duration of heated holding time. In a second “heat up and hold” or “rethermalizing” mode, the initial temperature of the pre-cooked food placed in the oven is lower than the desired holding temperature of the food, as where the food has been cooked and then refrigerated before placement in the holding oven. In this mode, thecontrol mechanism 140 is operable to activate the heat source in thecompartment 128 to raise the temperature in thecompartment 128 to the selected holding temperature during a duration of rethermalizing holding time, and for then controlling theheat source 146 in the at least onecompartment 128 to maintain the food in thecompartment 128 at the selected holding temperature for the duration of heated holding time. It will be understood that theoven 1 ofFIG. 1 can be used in a similar manner without departing from the scope of the invention. -
FIGS. 12 and 13 illustrate an example of the operation of the holdingoven 101 in the first (cool down and hold) mode. In particular,FIG. 12 illustrates a time vs. temperature curve for a complete duration of holding time D for onecompartment 128 of theoven 101, andFIG. 13 illustrates a time vs. activation curve for theheat source 146 of that same compartment during the holding time duration D. The time vs. temperature curve ofFIG. 12 plots the temperature of the food product as a function of time. One skilled in the art will understand that this curve can be different for each type of food product to be held in theoven 101. - In a cool down and hold situation, a food product is typically cooked as by frying, grilling, baking, etc., in a cooking appliance until a desired high internal temperature, usually between about 170 and 210 degrees Fahrenheit (° F.), is achieved. After the food is cooked, the food product is placed in a
tray 103 and inserted intocompartment 128 in theoven 101. Alternatively, the food can be placed in the oven without the use of a tray. Using thekeypad 142 or other input device, the operator selects a desired holding temperature, indicated at T, which will be lower than the temperature Tc of the food initially placed in the compartment. The holding temperature T is the desired temperature for maintaining the pre-cooked food to preserve taste, appearance and/or other food quality. The operator also selects a duration of holding time D. The duration of holding time D is the total time the food is to be held in theoven 101 and maintained at a desired quality level. Alternatively, thecontrol mechanism 140 can be programmed so that the operator need only select the type of food to be placed in the compartment and thecontrol mechanism 140 automatically uses preselected settings for that type of food. - In general, when the holding oven is operating in the cool down and hold mode, it is desirable that food introduced into the oven be allowed to quickly cool down to the selected holding temperature, and that the food be held at this temperature thereafter. Thus, the duration of holding time D may comprise an ambient hold time, i.e., a period of non-heated cool-down time such as indicated at B in
FIG. 12 , during which time the food product is allowed to cool to the desired holding temperature T. Preferably, during the ambient hold time B,heat source 146 is either in a deactivated state or a state in which it is delivering a relatively low quantity of radiant heat to the food so that the food product may cool down more rapidly than if the heat source was at full power. The food product is allowed to cool for the ambient hold time B until it reaches the desired hold temperature T as illustrated at point A. In one embodiment, forced air flow from the forced air mechanism 154 (FIG. 9 ) can be used to more rapidly decrease the temperature. After the internal temperature of the food decreases to the desired hold temperature T, the food is held near the desired hold temperature to preserve food quality for a period of heated hold time, indicated at C, comprising the remaining portion of the holding time duration D. During the heated holding time C, theheat source 146 may be operated in duty cycles to apply the appropriate amount of radiant heat to the food. Additionally, thecontrol mechanism 140 controls theheat sources fan system 156 to maintain the internal food temperature at or near the desired hold temperature T during the heated hold time C. -
FIG. 13 illustrates an embodiment in which theheat source 146 is successively activated and deactivated in a controlled sequence or duty cycle, indicated at G, to maintain the temperature in thecompartment 128 near the selected holding temperature T. In this particular embodiment, each duty cycle G comprises a heating interval E during which time theheat source 146 is activated followed by a non-heating interval F during which time the heat source is deactivated. The time-base of the duty cycle G is the time required to complete one cycle of activation and deactivation of theheat source 146 as shown inFIG. 13 . In one embodiment, the time-base of the duty cycle G and the percent on time of the heat source 146 (i.e., the duration of heating interval E divided by the time-base of the duty cycle G expressed as a percent) maintains the actual temperature within thecompartment 128 within at least about 15 degrees of the desired temperature, preferably within at least about 10 degrees, more preferably within about 5 degrees, and even more preferably within about 2 degrees of the desired temperature. - The operator is able to set various parameters using the
keypad 142 or other input device of thecontrol mechanism 140, such as the ambient hold time delay B, the heating interval E, the time-base of the duty cycle G, and/or total hold time D. These parameters can be selected by the operator or preset for the type of food product in thecompartment 128 so that the operator need only select the proper food product. Thecontrol mechanism 140 in anoven 101 having more than onecompartment 128 can control the duty cycle of theheat source 146 in each compartment to maintain the temperatures in the compartments at different levels. - Using the
keypad 142 or other input device, an operator can also control the operation of the forced air mechanism 154 (FIG. 9 ) by activating thefan system 156 or selecting the direction of forced air flow. In one embodiment, forced air flow from the forcedair mechanism 154 conveys convective heating air into thecompartments 128 at locations below thetrays 103 for flow in a generally upward direction toward thetrays 103. Alternately, the ventilation system conveys heating air into thecompartments 128 at locations above thetrays 103 for flow in a generally downward direction toward thetrays 103. Thefan system 156 can be operated such that heating air is circulated through thecompartments 128 in one direction and then the direction of air flow is reversed to circulate heating air through thecompartments 128 in the opposite direction. Using thekeypad 142 or other input device of thecontrol mechanism 140, the operator is able to select the duration that thefan system 156 circulates air through thecompartments 128. For example, in one embodiment, the forcedair mechanism 154 operates in a controlled sequence during the duty cycle G such that thefan system 156 is activated when theheat sources 146 are activated and is deactivated when the heat sources are deactivated. Alternately, thefan system 156 can be continuously activated for the duration of the total hold time D or can be activated so that the fan system is on a desired percentage of the duty cycle G independent of the heat sources. Preferably, thefan system 156 is activated a suitable percentage of the time to control the evaporation of moisture from the food in thecompartment 128. The percentage of time thefan system 156 is activated desirably depends on the type and/or the amount of food placed in thecompartment 128. The percentage of time thefan system 156 is activated and the direction of air flow can be selected by the operator or preset for the type of food product in thecompartment 128 so that the operator need only select the proper food product. Additionally, the vertical position of at least onetray 103 in arespective compartment 128 may be varied. - Set forth below are exemplary oven settings for particular food products when the oven is operating in a cool down and hold mode.
-
-
- Ambient hold time delay (B)=10 minutes
- Hold temperature (T)=180° F.
- Time-base of duty cycle (G)=120 seconds
- Percent on time (E)=50%
- Total hold time (D)=60 minutes
-
-
- Ambient hold time delay (B)=25 minutes
- Hold temperature (T)=200° F.
- Time base of duty cycle (G)=120 seconds
- Percent on time (E)=40%
- Total hold time (D)=240 minutes
-
FIGS. 14 and 15 illustrate an example of the operation of theoven 101 in the second (heat up and hold or rethermalizing) mode. In particular,FIG. 14 illustrates a time vs. temperature curve for a complete hold cycle D for onecompartment 128 of theoven 101, andFIG. 15 illustrates a time vs. activation curve for theheat source 146 of that same compartment during the hold cycle D. The time vs. temperature curve ofFIG. 14 plots the temperature of the food product as a function of time. One skilled in the art will understand that this curve can be different for each type of food product to be held in theoven 101. - In this mode, the
oven 101 is used to raise the temperature of a food product to a selected temperature and hold the food product at the selected temperature. Atray 103 containing a food product at an initial temperature T1 is placed into thecompartment 128. (Temperature T1 may vary from a frozen or refrigerated temperature to ambient or above.) Using thekeypad 142 or other input device, the operator selects a desired holding temperature T (which will be higher than the initial food temperature TI), and a duration of holding time D. Alternatively, thecontrol mechanism 140 can be programmed so that the operator need only select the type of food to be placed in the compartment and thecontrol mechanism 140 automatically uses preselected settings for that type of food. In either case, the control mechanism is operable to activate theheat source 146 to raise the temperature of the food product for a duration of heat-up or rethermalization time, indicated at I, the food reaching the holding temperature T at time H. Theheat source 146 is then activated and deactivated during the heated holding time C for successive duty cycles G to maintain the food in thecompartment 128 at the selected holding temperature T for the duration the total hold time D. In one embodiment, the duration of the heated holding time C includes intervals of the duty cycle G when theheat source 146 is activated as indicated by E and intervals during which the heat source is deactivated as indicated by F as described above. - Set forth below are exemplary oven settings for particular food products when the oven is operating in a heat-up and hold mode.
-
-
- Rethermalization time (I)=40 minutes
- Hold temperature(T)=220° F.
- Time-base of duty cycle (G)=180 seconds
- Percent on time (E)=50%
- Total hold time(D)=160 minutes
-
-
- Rethermalization time (I)=30 minutes
- Hold temperature(T)=210° F.
- Time base of duty cycle (G)=180 seconds
- Percent on time (E)=30%
- Total hold time(D)=240 minutes
- With the heating system of the present invention and the capability of controlling the evaporation of moisture from the
trays 103, the holding time (D) for fast service cooked foods such as chicken and french fries is substantially increased, and good texture and taste are maintained. In this respect, controlling the rate of evaporation of moisture from chicken, for example, precludes drying out and toughening of the chicken fibers and precludes the breading from becoming dry and greasy. And with respect to french fries, for example, development of a dry, rubbery texture as moisture is lost and the outer skin loses crispness is precluded. - In the embodiments described above, the
control mechanism 140 uses a duty-cycle system to control the amount of radiant heat delivered to the pre-cooked food by the heat sources. In this type of system, the percentage of heater on and off time is adjusted to vary the radiant energy as needed to maintain the food at the suitable holding temperature. It will be understood, however, that thecontrol mechanism 140 can vary the amount of radiant energy delivered to the food in other ways. For example, theheat sources 146 may be variable-power heaters operable to deliver radiant heat at multiple discrete energy levels or at an infinite number of levels between full-power and zero power (as by varying the voltage to the heaters), and thecontrol mechanism 140 may operate to increase and decrease the radiant heat delivered by the heaters in a controlled, pre-programmed manner to maintain a particular food at its ideal holding temperature. - The particular program used by the
control mechanism 140 to control aheat source 146 for any given type of food may be determined empirically. Alternatively, thecontrol mechanism 140 can include one or more sensors and one or more appropriate feedback loops for each compartment or group of components of the holding oven. For example, in one embodiment, at least one sensor is used in each compartment to detect a characteristic indicative of the temperature of the food in the compartment, and the control mechanism is responsive to signals received from the at least one sensor to control theheat source 146 to vary the radiant heat delivered to the pre-cooked food to maintain it at a holding temperature appropriate for that food. The characteristic detected by the one or more sensors may be the temperature of the air in the compartment, or the temperature of a surface in the compartment, or the radiant IR energy emitted by the food in the compartment, or some other characteristic. Thus, the sensor may be a standard temperature sensor, or an IR emissions detector, or some other type of detector capable of detecting the aforesaid characteristic indicative of the temperature of the food in the compartment. -
FIGS. 16-21 show another embodiment of food warming apparatus of this invention, generally designated 201. The apparatus comprises acabinet 203 having two horizontal tiers of compartments, two compartments per tier (each compartment being designated 207). It will be understood that the number of tiers can vary from one to any number more than one, and that the number ofcompartments 207 in each tier may vary from one to any number more than one. In the particular embodiment shown, each compartment is sized to receive a single tray T, but it will be understood that eachcompartment 207 may be sized to receive more than one tray, or that some compartments may be sized to receive one tray and other compartments more than one tray. In other embodiments (to be discussed later), food is placed in one ormore compartments 207 without the use of a tray. - The
cabinet 203 has front andback panels openings 215 aligned with thecompartments 207 in the cabinet to allow food (either in or out of trays T) to be placed into the compartments and removed from the compartments from both ends of the compartments. The cabinet also has abottom wall 221,side walls 223, atop wall 225, a vertical partition ordivider 227 extending between the top and bottom walls of the cabinet to separate the twocompartments 207 in each tier, and a horizontal partition ordivider 231 extending between theside walls 223 to separate the compartments in the upper tier from the compartments in the lower tier. As a result, the interior of the cabinet is divided into a plurality of separate, thermally isolated holdingcompartments 207, and each compartment is completely enclosed on opposite sides, top and bottom so that food flavors are prevented (or at least inhibited) from transferring between compartments. Suitable thermal insulation (not shown) is provided adjacent the walls of eachcompartment 207. - As shown in
FIG. 19 , for example eachcompartment 207 has aheat source 235 for emitting radiant heat down on pre-cooked food in the compartment. As noted previously, thisheat source 225 may comprise one or more IR heat lamps or the like, each mounted by a suitable fixture adjacent to the top wall of the compartment. Areflector 241 is provided in eachcompartment 207 over thebest source 235 for reflecting radiant heat in a generally downward direction through acover panel 245 of suitable material capable of transmitting the heat (e.g., glass). The food in thecompartment 207 is positioned a distance D1 below theheat source 235, as shown inFIG. 19 . Distance D1 is desirably relatively small to reduce or minimize the size (e.g., vertical height) of thecabinet 203. In one embodiment, for example, distance D1 is less than 12 in.; in another it is less than 11 in.; in another it is less than 10 in.; in another it is less than 9 in.; in another it is less than 8 in.; in another it is less than 7 in.; in another it is less than 6 in.; in another it is less than 5 in.; in another it is less than 4 in.; in another it is less than 3 in.; in another it is less than 2 in.; in another it is less than 1 in.; and in another it less than 0.5 in. In other embodiments, distance D1 may be in the range of 0.25 in. to 10 in., or in the range of 0.25 in. to 8 in., or in the range of 0.25 in. to 6 in., or in the range of 0.25 to 4 in., or in the range of 0.25 to 3 in., or in the range of 0.25 in. to 2 in., or in the range of 0.25 in. to 1 in. Where the pre-cooked food is placed in one or more trays, as shown inFIG. 19 , each tray T is supported bysupports 247 in arespective compartment 207 at an elevation where the bottom of the tray is spaced above the floor of the compartment a suitable distance D2. Distance D2 may be in the range of 0-12 in., and more preferably 0.5-1.0 in. Alternatively, the food may be placed on the floor of the compartment. - The
heat sources 235 in thecabinet 203 are controlled by asuitable control mechanism 251, similar to thecontrol mechanism 140 described above, which can be used to operate eachheat source 235 independently of the other heat sources to deliver varying amounts of radiant energy to the food in a respective compartment. In this manner, the amount of radiant energy delivered to the food in acompartment 207 can be closely controlled to maintain the food at an appropriate holding temperature for that particular food, as described above. Also, because the amount of radiant heat delivered to the food is varied as a function of time, theheat source 235 in eachcompartment 207 can be placed much closer to the food (e.g., distance D1 inFIG. 19 , discussed above) which has the desirable advantage of reducing the size of thecabinet 203. This is in contrast to conventional IR holding units where the energy delivered by the heat source is not variable. Rather, the heat source is energized to deliver full power all of the time. As a result, the heat source must be positioned relatively far from the food (e.g., 12 in. or more). - In one embodiment, the
control mechanism 251 is programmed for different types of food, so that after food has been placed in aparticular compartment 207, an operator simply selects that type of food from a suitable menu on a display (not shown) on the cabinet. The control mechanism then automatically selects the appropriate heating protocol for the food selected, including one or more of the following: the ideal holding temperature for the food selected; the duration of holding time (“holding duration”); and the manner in which the heat source in each compartment is to be varied to maintain the food at the desired holding temperature (e.g., percent on time during each duty cycle, if duty cycles are used). For convenience, thecontrol 251 also includes a timer which times out the holding duration, and adisplay 255 which shows the time remaining until the end of holding duration. Thecontrol mechanism 251 may also include a visual and/or audible alarm for alerting an operator at a predetermined time before the end of the holding duration, so that steps can be taken to start cooking a fresh batch or batches of additional food. (At the end of a holding duration, any food remaining in thecompartments 207 is typically disposed of and replaced by freshly cooked food.) - As noted previously, an important aspect of this invention is the ability of the
control mechanism 251 to vary the amount of radiant heat delivered by the heat source in eachcompartment 207 to the pre-cooked food in the compartment. In general, or at least typically, it is desirable that pre-cooked food introduced into the compartment be allowed to cool down as quickly as possible to the desired holding temperature, and that the food be held relatively constant at the desired holding temperature using a minimum of power to theheat source 235. The graphs inFIGS. 22A and 22B illustrate this concept.FIG. 22A graphs time v. temperature in onecompartment 207. Pre-cooked food introduced into the compartment at time T0 cools down to the desired holding temperature at time T1. Thereafter, the food is substantially maintained at the holding temperature for the remainder of the holding duration D.FIG. 22B is a graph of time v. the radiant energy delivered by theheat source 235 to the food. In the particular embodiment shown in this graph, the heat source is operated at a first relatively low level (where the heater is either off or delivering radiant heat at low level of energy or power) during a first phase P1 from time T0 to time T1, so that little or no radiant energy is delivered to the food. As a result, the temperature of the food declines relatively rapidly toward ambient temperature. When the temperature of the food approaches (or reaches) the desired holding temperature, thecontrol mechanism 251 causes theheat source 235 in thecompartment 207 to deliver radiant heat at a second higher level (e.g., 70% of maximum) to stop the decline in temperature of the food and hold it at about the desired holding temperature during a second phase P2 from time T1 to time T2. After the temperature of the food has equilibrated at the desired holding temperature, which will vary depending on the particular type of food, thecontrol mechanism 251 causes theheat source 235 to reduce the amount of radiant heat delivered to the food to a third level (e.g., 30% maximum) sufficient to maintain the food at the desired holding temperature during a third phase P3 from time T2 until the end of the holding period at time T3. - It will be understood that the graphs shown in
FIGS. 22A and 22B can vary, and that the number of phases P1, P2, P3 discussed above can vary without departing from the scope of this invention. -
FIG. 23 shows another embodiment of a holding oven of this invention, generally designated 301. The oven is similar to those described above except that the cabinet of the unit has only one compartment. In this embodiment, food is not placed in a tray, but rather on thebottom wall 307 or other supporting surface in the compartment, and theheat source 311 is closely spaced above the food to heat the food and maintain it at the desired holding temperature. The spacing D1 between the food and the IR heat source is relatively small (as discussed above) to reduce the overall height dimension of theoven 301. Theheat source 311 is controlled by acontrol mechanism -
FIG. 24 shows a holding oven, generally designated 401, which is similar to the oven shown inFIG. 23 . In this embodiment, thesingle compartment 403 of the oven is sized to hold multiple trays T. All other aspects of the oven, including the heat source and control mechanism, are the same. -
FIG. 25 shows a holding oven, generally designated 501, which is similar to the oven shown inFIG. 24 except that the oven is divided into threecompartments 503, each of which is capable of receiving food placed on the bottom wall or other supporting surface in the compartment.Partitions 507 between the compartments prevent or at least inhibit the transfer of food flavors between adjacent compartments. Eachcompartment 503 has itsown heat source 511 which is spaced relatively closely to the bottom wall of the compartment to maintain the distance between the food and the heat source within the ranges (e.g., distance D1) described above. Theheat sources 511 are controlled by a control mechanism similar to thecontrol mechanism - When introducing elements of the present invention or the preferred embodiment(s) thereof, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.
- In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained. As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
Claims (21)
1. A method of preserving cooked food, comprising the steps of:
cooking food in a cooking appliance to provide pre-cooked food;
placing the pre-cooked food in a holding compartment of a food warming apparatus for a duration of holding time; and
heating the pre-cooked food in the holding compartment for at least a portion of said duration of holding time by delivering in a pre-programmed manner an amount of radiant heat to the pre-cooked food from a radiant heat source positioned above the pre-cooked food;
said heating step comprising varying the amount of radiant heat delivered to the pre-cooked food to maintain the food at a selected holding temperature by delivering radiant heat to the pre-cooked food at a first level during a first phase of the duration of holding time and delivering radiant heat to the pre-cooked food at a second level during a second phase of the duration of holding time.
2. A method as set forth in claim 1 wherein said first level and said second level are both less than a maximum level of radiant heat deliverable from the radiant heat source.
3. A method as set forth in claim 1 wherein said first level of radiant heat permits said pre-cooked food to cool down to the selected holding temperature and said second level of radiant heat is higher than the first level to hold the pre-cooked food at the selected holding temperature.
4. A method as set forth in claim 3 wherein said heating step further comprises delivering radiant heat to the pre-cooked food at a third level less than said second level during a third phase of the duration to maintain said pre-cooked food at the selected holding temperature.
5. A method as set forth in claim 1 wherein said pre-cooked food placed in the compartment is at a temperature greater than ambient temperature, and said heating step comprises not delivering any substantial radiant heat to the pre-cooked food until the food has cooled to a temperature approaching said selected holding temperature.
6. A method as set forth in claim 1 wherein said pre-cooked food placed in the compartment is at a temperature below ambient temperature, and said heating step comprises delivering radiant heat to the pre-cooked food until the food reaches said selected holding temperature.
7. A method as set forth in claim 1 further comprising sensing a characteristic indicative of the temperature of the pre-cooked food in the compartment, and varying the amount of radiant heat delivered to the food according to said sensed characteristic.
8. A method as set forth in claim 7 wherein said sensed characteristic is a temperature of a surface in said holding compartment.
9. A method as set forth in claim 7 wherein said sensed characteristic is an amount of radiant energy emitted by said pre-cooked food.
10. A method as set forth in claim 1 further comprising placing said pre-cooked food in said holding oven at a location within a distance of less then 12 in. from said source of radiant heat.
11. A method as set forth in claim 1 further comprising placing said pre-cooked food in said holding oven at a location within a distance of less then 10 in. from said source of radiant heat.
12. A method as set forth in claim 1 further comprising placing said pre-cooked food in said holding oven at a location within a distance of less then 8 in. from said source of radiant heat.
13. A method as set forth in claim 1 further comprising placing said pre-cooked food in said holding oven at a location within a distance of less then 6 in. from said source of radiant heat.
14. A method as set forth in claim 1 further comprising placing said pre-cooked food in said holding oven at a location within a distance of less then 4 in. from said source of radiant heat.
15. A method as set forth in claim 1 further comprising placing said pre-cooked food in said holding oven at a location within a distance of less then 2 in. from said source radiant heat.
16. A method of controlling a food holding oven, said oven comprising a cabinet, a plurality of separate, thermally isolated holding compartments in the cabinet, a plurality of trays for containing pre-cooked food having been previously 5 cooked in a cooking appliance, each compartment being adapted for removably receiving one tray per compartment, and heat sources above respective trays adapted for activation to emit radiant heat to the food in the trays to warm the food, said method comprising:
setting a selected holding temperature for each compartment;
setting a duration of holding time for each compartment, said duration of holding time comprising a duration of heated holding time; and
varying the amount of radiant heat delivered to the pre-cooked food during a respective duration of heated holding time to maintain the food in a respective compartment at said selected holding temperature.
17. A method as set forth in claim 16 wherein said varying the amount of radiant heat comprises delivering radiant heat to the pre-cooked food at a first level during a first phase of the duration of holing time and delivering radiant heat to the pre-cooked food at a second level during a second phase of the duration of holding time.
18. A method as set forth in claim 17 wherein said first level of radiant heat permits said pre-cooked food to cool down to the selected holding temperature during said first phase and said second level of radiant heat is higher than the first level to hold the pre-cooked food at the selected holding temperature.
19. A method as set forth in claim 18 wherein said varying the amount of radiant heat further comprises delivering radiant heat to the pre-cooked food at a third level less than said second level during a third phase of the duration to maintain said pre-cooked food at the selected holding temperature.
20. A method as set forth in claim 16 further comprising maintaining at least two compartments at different selected holding temperatures.
21. A method as set forth in claim 16 further comprising placing said pre-cooked food in a respective compartment at a location within a distance of less then 12 in. from a respective heat source.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/185,482 US20050255208A1 (en) | 2002-07-10 | 2005-07-20 | Food warming apparatus and method |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US39484102P | 2002-07-10 | 2002-07-10 | |
US10/611,295 US7227102B2 (en) | 2002-07-10 | 2003-07-01 | Food warming apparatus and method |
US10/680,626 US7105779B2 (en) | 2002-07-10 | 2003-10-07 | Food warming apparatus and method |
US11/185,482 US20050255208A1 (en) | 2002-07-10 | 2005-07-20 | Food warming apparatus and method |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/680,626 Division US7105779B2 (en) | 2002-07-10 | 2003-10-07 | Food warming apparatus and method |
Publications (1)
Publication Number | Publication Date |
---|---|
US20050255208A1 true US20050255208A1 (en) | 2005-11-17 |
Family
ID=34435373
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/680,626 Expired - Fee Related US7105779B2 (en) | 2002-07-10 | 2003-10-07 | Food warming apparatus and method |
US11/185,482 Abandoned US20050255208A1 (en) | 2002-07-10 | 2005-07-20 | Food warming apparatus and method |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/680,626 Expired - Fee Related US7105779B2 (en) | 2002-07-10 | 2003-10-07 | Food warming apparatus and method |
Country Status (12)
Country | Link |
---|---|
US (2) | US7105779B2 (en) |
EP (1) | EP1677607B1 (en) |
CN (1) | CN1889844A (en) |
AT (1) | ATE428302T1 (en) |
AU (1) | AU2004279413A1 (en) |
BR (1) | BRPI0415181A (en) |
CA (1) | CA2541649C (en) |
DE (1) | DE602004020646D1 (en) |
ES (1) | ES2325994T3 (en) |
PL (1) | PL1677607T3 (en) |
TW (1) | TWI279507B (en) |
WO (1) | WO2005034633A1 (en) |
Cited By (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20060266915A1 (en) * | 2005-05-24 | 2006-11-30 | Ice Cube, Inc. | Tray mold |
US20070254079A1 (en) * | 2006-04-28 | 2007-11-01 | Restaurant Technology, Inc. | Food staging device, method of storing foods, and method of making a sandwich |
US20070251667A1 (en) * | 2006-04-28 | 2007-11-01 | Restaurant Technology, Inc. | Food staging device |
EP1867926A2 (en) | 2006-06-13 | 2007-12-19 | Rational AG | Cooking device with status monitoring of the food products |
US20080019617A1 (en) * | 2006-07-24 | 2008-01-24 | Rasquinha Clarence A | Method of packaging manufactured stone |
FR2939495A1 (en) * | 2008-12-09 | 2010-06-11 | Rational Ag | Cooking apparatus for use in professional kitchen for cooking e.g. baked egg, has display device presenting display sector in cooking chamber, and control device comprising inlet sector in cooking chamber |
US8307761B1 (en) | 2008-06-16 | 2012-11-13 | Low Temp Manufacturing Company | Multi-well food presentation modules |
US8450659B2 (en) | 2010-04-16 | 2013-05-28 | Restaurant Technology, Inc. | Control system and method for high density universal holding cabinet |
US8558142B2 (en) | 2010-04-16 | 2013-10-15 | Restaurant Technology, Inc. | High density universal holding cabinet |
US8993026B2 (en) * | 2013-05-06 | 2015-03-31 | Sci Direct, Llc | Infrared portable broiler |
WO2021202415A1 (en) * | 2020-04-02 | 2021-10-07 | Automation Tech, LLC | Modular cooking appliance |
US11739942B2 (en) | 2020-04-02 | 2023-08-29 | Automation Tech, LLC | Modular cooking appliance having a hot air oven with a built-in magnetron and a double duty heater |
US11737467B2 (en) | 2020-04-02 | 2023-08-29 | Automation Tech, LLC | Method for cooking in a modular cooking appliance |
USD1005781S1 (en) | 2021-01-29 | 2023-11-28 | Duke Manufacturing Co. | Liner for a food holding well |
US11912465B2 (en) | 2021-01-27 | 2024-02-27 | Duke Manufacturing Co. | Liner for food receiver of food holding apparatus |
Families Citing this family (76)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7258064B2 (en) * | 2002-09-04 | 2007-08-21 | Prince Castle, Inc. | Food product timing system |
DE10337161A1 (en) * | 2003-08-13 | 2005-03-10 | Rational Ag | Cooking appliance for regenerating food |
US10133992B2 (en) * | 2005-04-07 | 2018-11-20 | Mgs Modular Galley Systems Ag | System and method for monitoring manufactured pre-prepared meals |
US7921767B2 (en) * | 2005-05-13 | 2011-04-12 | Burger King Corporation | Automatic broiler for variable batch cooking |
US8033213B2 (en) | 2005-05-13 | 2011-10-11 | Burger King Corporation | Automatic broiler for variable batch cooking |
KR101016353B1 (en) * | 2005-10-17 | 2011-02-22 | 메르코/세이보리 엘엘씨 | Food holding cabinet with removable tray covers |
US7446282B2 (en) * | 2006-07-25 | 2008-11-04 | Duke Manufacturing Co. | Food service apparatus and methods |
US8126319B2 (en) * | 2006-08-10 | 2012-02-28 | De Luca Oven Technologies, Llc | Radiant oven with stored energy devices and radiant lamps |
US8498526B2 (en) * | 2008-12-30 | 2013-07-30 | De Luca Oven Technologies, Llc | Wire mesh thermal radiative element and use in a radiative oven |
JP2010502925A (en) * | 2006-08-29 | 2010-01-28 | メルコ/サヴォリー エルエルシー | Cooking preservation system and method with ribbed tray |
US7755006B2 (en) * | 2006-12-05 | 2010-07-13 | General Electric Company | Heating systems and methods for a cooking appliance |
US8061266B2 (en) * | 2007-03-02 | 2011-11-22 | Track Corp. | Food warming and holding device construction and method |
US7858906B2 (en) * | 2007-06-08 | 2010-12-28 | Prince Castle, Inc. | Apparatus and method for maintaining cooked food in a ready-to-use condition |
US8071918B2 (en) * | 2007-10-30 | 2011-12-06 | Prince Castle LLC. | Controller for a food holding oven |
US7971523B2 (en) * | 2007-11-15 | 2011-07-05 | Prince Castle, Inc. | Removable divider for food warming apparatus |
US8096231B2 (en) * | 2008-02-12 | 2012-01-17 | Prince Castle, Inc. | Apparatus and method for maintaining cooked food in a ready-to-use condition |
US8091472B2 (en) * | 2008-04-25 | 2012-01-10 | Prince Castle, Inc. | Post-supported covers for food trays |
US20090320882A1 (en) * | 2008-06-27 | 2009-12-31 | Charles Richard Averwater | Barbecue smoker |
US8258440B2 (en) * | 2008-12-08 | 2012-09-04 | Duke Manufacturing Co. | Rethermalizing apparatus |
US8145548B2 (en) | 2008-12-30 | 2012-03-27 | De Luca Oven Technologies, Llc | Food vending machine system incorporating a high speed stored energy oven |
US20100288748A1 (en) * | 2009-05-15 | 2010-11-18 | Fortmann Robert C | Warming cart |
FR2947990B1 (en) * | 2009-07-16 | 2011-09-16 | Centre Nat Rech Scient | COOKING OVEN FOR FOOD AND COOKING PROCESS OF CEREAL-BASED PASTE |
WO2011015164A1 (en) * | 2009-08-07 | 2011-02-10 | Ibt Infrabiotech Gmbh | Device for thermally processing biological and technical goods or objects using ceramic infrared radiators having selective emission or absorption spectra |
US8499683B2 (en) * | 2009-08-08 | 2013-08-06 | Steven Michael Shei | Hot and cold food holding appliance |
US20110114618A1 (en) * | 2009-11-16 | 2011-05-19 | Prince Castle, Inc | Universal food holding cabinet with snap-in escutcheons |
US20110114625A1 (en) * | 2009-11-16 | 2011-05-19 | Prince Castle, Inc | Food holding cabinet with self-aligning and addressable power supplies |
US20110114624A1 (en) * | 2009-11-16 | 2011-05-19 | Prince Castle, Inc | Food holding cabinet power supplies with downloadable software |
US8895902B2 (en) | 2010-03-17 | 2014-11-25 | Duke Manufacturing Co. | Oven for heating food |
US9003820B2 (en) | 2010-04-20 | 2015-04-14 | Prince Castle LLC | Point-of-use holding cabinet |
US8362404B2 (en) | 2010-05-17 | 2013-01-29 | Carter Hoffmann, Inc. | Open warming cabinet |
US8607587B2 (en) | 2010-05-19 | 2013-12-17 | Prince Castle LLC | Refrigerated point-of-use holding cabinet |
US9068768B2 (en) | 2010-05-19 | 2015-06-30 | Prince Castle LLC | Refrigerated point-of-use holding cabinet with downloadable software |
US8522675B2 (en) | 2010-05-21 | 2013-09-03 | Prince Castle, LLC | Holding cabinet for separately heating food trays |
WO2011163217A1 (en) * | 2010-06-21 | 2011-12-29 | Egc Enterprises, Incorporated | Hermetically encapsulated electric heater |
IN2014CN02379A (en) * | 2011-09-21 | 2015-06-19 | Manitowoc Foodservice Co Inc | |
DE102012217053A1 (en) * | 2012-09-21 | 2014-03-27 | E.G.O. Elektro-Gerätebau GmbH | Process for preparing a food in an oven and oven |
WO2014071383A1 (en) | 2012-11-05 | 2014-05-08 | Duke Manufacturing Co. | Oven with various features, including boost heating and preheat status |
US9149154B1 (en) * | 2013-03-04 | 2015-10-06 | Marshall Air Systems, Inc. | Apparatus for transiently holding cooked food in a warm condition pending service of the food for consumption |
US10271690B2 (en) | 2013-03-15 | 2019-04-30 | Prince Castle LLC | Modular heating unit |
AU2014312362A1 (en) | 2013-08-27 | 2016-03-10 | Duke Manufacturing Co. | Food management system |
CN104414445B (en) * | 2013-08-28 | 2018-05-18 | 姚凌 | A kind of cooking method of cooking machine |
ITTO20131012A1 (en) * | 2013-12-11 | 2015-06-12 | Indesit Co Spa | TOASTERS AND METHOD OF CONTROL OF SUCH TOASTER |
CA2934274C (en) | 2013-12-16 | 2021-05-25 | Andrew Perkins | A continuous renewal system for a wire mesh heating element and a woven angled wire mesh |
USD749894S1 (en) | 2014-03-14 | 2016-02-23 | Duke Manufacturing Co. | Container lid |
AU2015256210A1 (en) | 2014-05-05 | 2016-11-24 | Duke Manufacturing Co. | Food processing management system |
US9854943B2 (en) | 2014-05-15 | 2018-01-02 | Prince Castle LLC | Modular food holding cabinet having individually configurable food holding units |
US10203108B2 (en) | 2014-08-14 | 2019-02-12 | De Luca Oven Technologies, Llc | Vapor generator including wire mesh heating element |
US9693655B2 (en) * | 2014-09-17 | 2017-07-04 | Duke Manufacturing Co. | Pan storage apparatus |
WO2016126714A1 (en) | 2015-02-02 | 2016-08-11 | Spectrum Brands, Inc. | Heating appliance |
US10088172B2 (en) | 2016-07-29 | 2018-10-02 | Alto-Shaam, Inc. | Oven using structured air |
US10890336B2 (en) | 2015-06-08 | 2021-01-12 | Alto-Shaam, Inc. | Thermal management system for multizone oven |
US9879865B2 (en) | 2015-06-08 | 2018-01-30 | Alto-Shaam, Inc. | Cooking oven |
US10337745B2 (en) | 2015-06-08 | 2019-07-02 | Alto-Shaam, Inc. | Convection oven |
US9677774B2 (en) | 2015-06-08 | 2017-06-13 | Alto-Shaam, Inc. | Multi-zone oven with variable cavity sizes |
US10455983B2 (en) * | 2015-09-10 | 2019-10-29 | Prince Castle LLC | Modular food holding system |
US9962038B2 (en) | 2015-09-10 | 2018-05-08 | Prince Castle LLC | Modular food holding system |
US10271689B2 (en) * | 2015-09-10 | 2019-04-30 | Prince Castle LLC | Modular food holding system |
US9901213B2 (en) * | 2015-09-10 | 2018-02-27 | Prince Castle LLC | Modular food holding system |
US10154757B2 (en) * | 2015-09-10 | 2018-12-18 | Prince Castle LLC | Modular food holding system |
CN105519616A (en) * | 2016-02-02 | 2016-04-27 | 安徽理工大学 | High-efficiency and semi-automatic food processing device |
US20170231430A1 (en) * | 2016-02-12 | 2017-08-17 | Nuwave, Llc | Air Fryer |
USD809326S1 (en) | 2016-04-19 | 2018-02-06 | Prince Castle LLC | Food holding bin |
US9980322B1 (en) | 2016-04-19 | 2018-05-22 | Prince Castle LLC | Multi-zone food holding bin |
US9976750B1 (en) | 2016-04-20 | 2018-05-22 | Prince Castle LLC | Multi-zone food holding bin |
US11185191B2 (en) | 2016-05-20 | 2021-11-30 | Marmon Foodservice Technologies, Inc. | Modular food holding system |
US10349777B2 (en) | 2016-10-18 | 2019-07-16 | Prince Castle LLC | Modular holding bin with power recovery mode |
US10136762B2 (en) | 2016-10-18 | 2018-11-27 | Prince Castle LLC | Modular holding bin having individually configurable food holding modules |
ES2963662T3 (en) * | 2017-09-14 | 2024-04-01 | Cleveland Range Llc | Tray Identification Accessory for Food Preservation Devices |
JP2020534498A (en) * | 2017-09-15 | 2020-11-26 | ホーム テック イノベーション,インコーポレイテッド | Equipment and methods for at least semi-autonomous dietary storage and cooking |
US11278157B2 (en) | 2018-03-22 | 2022-03-22 | Marmon Foodservice Technologies, Inc. | Food tray |
US11402103B2 (en) | 2018-10-16 | 2022-08-02 | Haler US Appliance Solutions, Inc. | Appliance user interface with increased control settings |
US11534025B2 (en) * | 2019-04-02 | 2022-12-27 | Malana Zehlka | Convertible multipurpose cooking mat |
EP3975806A4 (en) * | 2019-05-28 | 2023-02-08 | SharkNinja Operating LLC | Heated food processor |
US20220408966A1 (en) | 2019-07-15 | 2022-12-29 | Sharkninja Operating Llc | Cooking device and components thereof |
US11930825B2 (en) | 2019-11-05 | 2024-03-19 | Marmon Foodservice Technologies, Inc. | Dynamic cooking with limited control authority conveyor compensation |
US11717116B2 (en) * | 2021-07-16 | 2023-08-08 | Ludlow D. Forbes | Cooking method and apparatus |
Citations (74)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US466416A (en) * | 1892-01-05 | Cooking-pan | ||
US804110A (en) * | 1905-03-25 | 1905-11-07 | William Thomas Favorite | Corn-popper. |
US1627541A (en) * | 1926-09-02 | 1927-05-03 | Katzinger Edward Co | Covered pan |
US2076091A (en) * | 1935-03-08 | 1937-04-06 | Angus Roy Shannon | Oven |
US2257468A (en) * | 1939-09-15 | 1941-09-30 | Chicago Metallic Mfg Company | Cover for baking pans |
US2779497A (en) * | 1953-07-01 | 1957-01-29 | Ekco Products Company | Bake pan covers |
US2860225A (en) * | 1956-10-23 | 1958-11-11 | Steen Carl August | Electric heating apparatus |
US2964609A (en) * | 1957-07-01 | 1960-12-13 | Seymour M Anoff | Food preserving cabinet construction |
US3051582A (en) * | 1959-08-24 | 1962-08-28 | Southern Equipment Company | Method of storing prepared foods |
US3244859A (en) * | 1963-01-07 | 1966-04-05 | Poly Pak Corp Of America | Infrared food heater |
US3249741A (en) * | 1963-05-20 | 1966-05-03 | Reflectotherm Inc | Apparatus for baking by differential wave lengths |
US3313917A (en) * | 1963-11-21 | 1967-04-11 | Litton Prec Products Inc | Doorless infrared oven |
US3353886A (en) * | 1966-02-21 | 1967-11-21 | Edward L Tompkins | Thermally insulated container |
US3353885A (en) * | 1966-02-01 | 1967-11-21 | Howard C Hanson | Expansible multi-purpose cabinet |
US3597236A (en) * | 1967-08-08 | 1971-08-03 | Armour & Co | Process for preserving the color of fresh meat |
US3601582A (en) * | 1968-07-24 | 1971-08-24 | Iseco Sa | Apparatus for reheating portions of cooked food |
US3681568A (en) * | 1971-12-15 | 1972-08-01 | John Oster Mfg | Electrically heated cooking appliance |
US3751629A (en) * | 1957-07-24 | 1973-08-07 | P Eisler | Surface heating device |
US3752640A (en) * | 1970-07-09 | 1973-08-14 | F Schneider | Baking battery |
US3908749A (en) * | 1974-03-07 | 1975-09-30 | Standex Int Corp | Food service system |
US4020310A (en) * | 1975-03-20 | 1977-04-26 | Souder Jr James J | Container for inductively heating food |
US4024377A (en) * | 1975-09-10 | 1977-05-17 | Lincoln Manufacturing Company, Inc. | Hot well and method of heating |
US4099512A (en) * | 1976-12-27 | 1978-07-11 | Joseph Noonan | Heat-conserving cooking utensil |
US4110587A (en) * | 1975-03-20 | 1978-08-29 | Patents Licensing International, Ltd. | Method and apparatus for heating food |
US4154861A (en) * | 1976-05-19 | 1979-05-15 | Smith Donald P | Heat treatment of food products |
US4198559A (en) * | 1977-12-20 | 1980-04-15 | Clairol Incorporated | Heat retaining appliance |
US4235282A (en) * | 1976-12-31 | 1980-11-25 | Filippis Modeste De | Heating and refrigerating tray cabinet for distributing hot and cold dishes |
US4337384A (en) * | 1979-08-01 | 1982-06-29 | Matsushita Electric Industrial Co., Ltd. | Cooking appliance of the hot air circulating type |
US4374319A (en) * | 1979-11-27 | 1983-02-15 | Sunset Ltd. | Counter-top oven |
US4381442A (en) * | 1980-12-30 | 1983-04-26 | Sunset Ltd. | Counter-top unit for heating packaged food |
US4401884A (en) * | 1978-09-26 | 1983-08-30 | Matsushita Electric Industrial Co., Ltd. | Method of controlling heating in food heating apparatus including infrared detecting system |
US4467777A (en) * | 1980-07-10 | 1984-08-28 | Niro Plan Ag | Gas or electrically heated convection air oven for baking foods |
US4480164A (en) * | 1982-12-03 | 1984-10-30 | General Electric Company | Food browning system incorporating a combined microwave and hot air oven |
US4575616A (en) * | 1982-02-05 | 1986-03-11 | Aktiebolaget Electrolux | Domestic infra-red radiation oven |
US4587946A (en) * | 1985-02-01 | 1986-05-13 | Jacques Doyon | Mobile baking oven and proofer |
US4691088A (en) * | 1984-08-14 | 1987-09-01 | Microwave Ovens Limited | Microwave oven with power transfer automatically responsive to dielectric load of food |
US4784054A (en) * | 1986-08-28 | 1988-11-15 | Restaurant Technology, Inc. | Equipment for holding or staging packaged sandwiches |
US4967995A (en) * | 1989-02-27 | 1990-11-06 | John Burgess | Combination cover and dispenser for an ice cube tray |
US4972824A (en) * | 1988-12-02 | 1990-11-27 | Welbilt Corporation | Commercial hot air impingement cooking apparatus |
US5028761A (en) * | 1989-08-15 | 1991-07-02 | Jamco Corporation | Food service cart with a heating system, and trays and casseroles for such a food service cart |
US5050578A (en) * | 1988-12-02 | 1991-09-24 | Welbilt Corporation | Commercial hot air impingement cooking apparatus |
US5172682A (en) * | 1988-12-02 | 1992-12-22 | Welbilt Corporation | Commercial hot air impingement cooking apparatus |
US5188020A (en) * | 1991-10-11 | 1993-02-23 | Buchnag Kamal M | Food shelving and cycling system |
US5235903A (en) * | 1992-03-17 | 1993-08-17 | Tippmann Eugene R | Subatmospheric pressure cook-and-hold steaming oven |
US5365038A (en) * | 1992-02-14 | 1994-11-15 | Kabushiki Kaisha Nissei Giken | Covered defroster with a defrosting plate over a latent heat source |
US5434390A (en) * | 1991-09-17 | 1995-07-18 | Turbochef, Inc. | Quick-cookig oven |
US5496987A (en) * | 1993-06-10 | 1996-03-05 | Siccardi; Enrico | Electric oven, for domestic use, particularly designed to cooking pizzas, cakes and the like |
US5653905A (en) * | 1995-02-16 | 1997-08-05 | Mckinney; Eugene F. | Royalton natural air movement system |
US5699722A (en) * | 1989-03-17 | 1997-12-23 | Erickson; Chad | Rapid cooking device |
US5712464A (en) * | 1988-05-19 | 1998-01-27 | Quadlux, Inc. | Method and apparatus of cooking food in a lightwave oven |
US5717192A (en) * | 1990-01-10 | 1998-02-10 | Patentsmith Technology, Ltd. | Jet impingement batch oven |
US5724886A (en) * | 1995-05-11 | 1998-03-10 | Restaurant Technology, Inc. | Cooked food staging device and method |
US5783803A (en) * | 1995-12-20 | 1998-07-21 | Robards, Jr.; Chester F. | Food warming apparatus |
US5852967A (en) * | 1997-02-03 | 1998-12-29 | Restaurant Technology, Inc. | Food treatment system |
US5919389A (en) * | 1997-03-18 | 1999-07-06 | Sanyo Electric Co. Ltd. | Cooking apparatus including infrared ray sensor |
US5934178A (en) * | 1997-01-04 | 1999-08-10 | Heat & Control, Inc. | Air impingement oven |
US6011243A (en) * | 1996-06-27 | 2000-01-04 | Emerson Electric Co | Holding cabinet and method and apparatus for controlling a holding cabinet |
US6031208A (en) * | 1998-11-12 | 2000-02-29 | Hatco Corporation | Topless holding bin with side heat source |
US6175099B1 (en) * | 1999-03-31 | 2001-01-16 | Duke Manufacturing Co. | Holding or cooking oven |
US6262394B1 (en) * | 1999-03-31 | 2001-07-17 | Duke Manufacturing Co. | Holding or cooking oven |
US6262406B1 (en) * | 1997-05-27 | 2001-07-17 | Turbochef Technologies, Inc. | Compact quick-cooking convectional oven |
US20010025842A1 (en) * | 2000-03-07 | 2001-10-04 | Hatco Corporation | Oven device for rapid heating of food items |
US6376817B1 (en) * | 1998-10-09 | 2002-04-23 | Turbochef Technologies, Inc. | Compact quick-cooking oven |
US6412403B1 (en) * | 2000-02-29 | 2002-07-02 | Prince Castle, Inc. | Apparatus and method for maintaining cooked food in a ready-to-serve condition using a freestanding cover for food trays |
US6450085B1 (en) * | 1997-07-18 | 2002-09-17 | Gottfried Riesselmann | Apparatus for cooking dishes by heating |
US20030047553A1 (en) * | 2001-09-07 | 2003-03-13 | Anthony Patti | Multiple panel oven having individual controls for combined conductive and radiant heating panels |
US6539846B2 (en) * | 2001-05-17 | 2003-04-01 | Tecnhos S.R.L. | Apparatus for delivering meals at an appropriate temperature, particularly for use in hospitals |
US6545251B2 (en) * | 2000-10-26 | 2003-04-08 | Whirlpool Corporation | Cooking oven |
US6658994B1 (en) * | 2002-04-10 | 2003-12-09 | Chromalox, Inc. | Modular assembly for a holding cabinet controller |
US6710308B2 (en) * | 2002-07-31 | 2004-03-23 | Maytag Corporation | Automatic cook sequencing system for multiple ovens |
US20040056015A1 (en) * | 2002-07-31 | 2004-03-25 | Maytag Corporation | Automatic cook sequencing system for multiple ovens with refrigeration unit |
US6878904B2 (en) * | 2003-01-27 | 2005-04-12 | Nicholas G. Verveniotis | Grilling station |
US7279659B2 (en) * | 2004-09-01 | 2007-10-09 | Western Industries, Inc. | Non-food warmer appliance |
US7307243B2 (en) * | 2003-05-09 | 2007-12-11 | North Carolina State University | Dynamic radiant food preparation methods and systems |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB829729A (en) | 1957-04-22 | 1960-03-09 | Gen Motors Corp | Improved electric oven |
KR100811923B1 (en) * | 2002-07-10 | 2008-03-10 | 듀크 매뉴팩쳐링 컴퍼니 | Food warming apparatus and method |
-
2003
- 2003-10-07 US US10/680,626 patent/US7105779B2/en not_active Expired - Fee Related
-
2004
- 2004-10-06 AT AT04794322T patent/ATE428302T1/en not_active IP Right Cessation
- 2004-10-06 AU AU2004279413A patent/AU2004279413A1/en not_active Abandoned
- 2004-10-06 PL PL04794322T patent/PL1677607T3/en unknown
- 2004-10-06 CA CA2541649A patent/CA2541649C/en active Active
- 2004-10-06 DE DE602004020646T patent/DE602004020646D1/en active Active
- 2004-10-06 BR BRPI0415181-0A patent/BRPI0415181A/en not_active Application Discontinuation
- 2004-10-06 WO PCT/US2004/032926 patent/WO2005034633A1/en active Application Filing
- 2004-10-06 CN CNA2004800362755A patent/CN1889844A/en active Pending
- 2004-10-06 ES ES04794322T patent/ES2325994T3/en active Active
- 2004-10-06 EP EP04794322A patent/EP1677607B1/en not_active Not-in-force
- 2004-10-07 TW TW093130397A patent/TWI279507B/en not_active IP Right Cessation
-
2005
- 2005-07-20 US US11/185,482 patent/US20050255208A1/en not_active Abandoned
Patent Citations (80)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US466416A (en) * | 1892-01-05 | Cooking-pan | ||
US804110A (en) * | 1905-03-25 | 1905-11-07 | William Thomas Favorite | Corn-popper. |
US1627541A (en) * | 1926-09-02 | 1927-05-03 | Katzinger Edward Co | Covered pan |
US2076091A (en) * | 1935-03-08 | 1937-04-06 | Angus Roy Shannon | Oven |
US2257468A (en) * | 1939-09-15 | 1941-09-30 | Chicago Metallic Mfg Company | Cover for baking pans |
US2779497A (en) * | 1953-07-01 | 1957-01-29 | Ekco Products Company | Bake pan covers |
US2860225A (en) * | 1956-10-23 | 1958-11-11 | Steen Carl August | Electric heating apparatus |
US2964609A (en) * | 1957-07-01 | 1960-12-13 | Seymour M Anoff | Food preserving cabinet construction |
US3751629A (en) * | 1957-07-24 | 1973-08-07 | P Eisler | Surface heating device |
US3051582A (en) * | 1959-08-24 | 1962-08-28 | Southern Equipment Company | Method of storing prepared foods |
US3244859A (en) * | 1963-01-07 | 1966-04-05 | Poly Pak Corp Of America | Infrared food heater |
US3249741A (en) * | 1963-05-20 | 1966-05-03 | Reflectotherm Inc | Apparatus for baking by differential wave lengths |
US3313917A (en) * | 1963-11-21 | 1967-04-11 | Litton Prec Products Inc | Doorless infrared oven |
US3353885A (en) * | 1966-02-01 | 1967-11-21 | Howard C Hanson | Expansible multi-purpose cabinet |
US3353886A (en) * | 1966-02-21 | 1967-11-21 | Edward L Tompkins | Thermally insulated container |
US3597236A (en) * | 1967-08-08 | 1971-08-03 | Armour & Co | Process for preserving the color of fresh meat |
US3601582A (en) * | 1968-07-24 | 1971-08-24 | Iseco Sa | Apparatus for reheating portions of cooked food |
US3752640A (en) * | 1970-07-09 | 1973-08-14 | F Schneider | Baking battery |
US3681568A (en) * | 1971-12-15 | 1972-08-01 | John Oster Mfg | Electrically heated cooking appliance |
US3908749A (en) * | 1974-03-07 | 1975-09-30 | Standex Int Corp | Food service system |
US4020310A (en) * | 1975-03-20 | 1977-04-26 | Souder Jr James J | Container for inductively heating food |
US4110587A (en) * | 1975-03-20 | 1978-08-29 | Patents Licensing International, Ltd. | Method and apparatus for heating food |
US4024377A (en) * | 1975-09-10 | 1977-05-17 | Lincoln Manufacturing Company, Inc. | Hot well and method of heating |
US4154861A (en) * | 1976-05-19 | 1979-05-15 | Smith Donald P | Heat treatment of food products |
US4099512A (en) * | 1976-12-27 | 1978-07-11 | Joseph Noonan | Heat-conserving cooking utensil |
US4235282A (en) * | 1976-12-31 | 1980-11-25 | Filippis Modeste De | Heating and refrigerating tray cabinet for distributing hot and cold dishes |
US4198559A (en) * | 1977-12-20 | 1980-04-15 | Clairol Incorporated | Heat retaining appliance |
US4401884A (en) * | 1978-09-26 | 1983-08-30 | Matsushita Electric Industrial Co., Ltd. | Method of controlling heating in food heating apparatus including infrared detecting system |
US4337384A (en) * | 1979-08-01 | 1982-06-29 | Matsushita Electric Industrial Co., Ltd. | Cooking appliance of the hot air circulating type |
US4374319A (en) * | 1979-11-27 | 1983-02-15 | Sunset Ltd. | Counter-top oven |
US4467777A (en) * | 1980-07-10 | 1984-08-28 | Niro Plan Ag | Gas or electrically heated convection air oven for baking foods |
US4381442A (en) * | 1980-12-30 | 1983-04-26 | Sunset Ltd. | Counter-top unit for heating packaged food |
US4575616A (en) * | 1982-02-05 | 1986-03-11 | Aktiebolaget Electrolux | Domestic infra-red radiation oven |
US4480164A (en) * | 1982-12-03 | 1984-10-30 | General Electric Company | Food browning system incorporating a combined microwave and hot air oven |
US4691088A (en) * | 1984-08-14 | 1987-09-01 | Microwave Ovens Limited | Microwave oven with power transfer automatically responsive to dielectric load of food |
US4587946A (en) * | 1985-02-01 | 1986-05-13 | Jacques Doyon | Mobile baking oven and proofer |
US4784054A (en) * | 1986-08-28 | 1988-11-15 | Restaurant Technology, Inc. | Equipment for holding or staging packaged sandwiches |
US5712464A (en) * | 1988-05-19 | 1998-01-27 | Quadlux, Inc. | Method and apparatus of cooking food in a lightwave oven |
US5172682A (en) * | 1988-12-02 | 1992-12-22 | Welbilt Corporation | Commercial hot air impingement cooking apparatus |
US5345923A (en) * | 1988-12-02 | 1994-09-13 | Welbilt Corporation | Commercial hot air impingement cooking apparatus |
US5050578A (en) * | 1988-12-02 | 1991-09-24 | Welbilt Corporation | Commercial hot air impingement cooking apparatus |
US4972824A (en) * | 1988-12-02 | 1990-11-27 | Welbilt Corporation | Commercial hot air impingement cooking apparatus |
US4967995A (en) * | 1989-02-27 | 1990-11-06 | John Burgess | Combination cover and dispenser for an ice cube tray |
US5699722A (en) * | 1989-03-17 | 1997-12-23 | Erickson; Chad | Rapid cooking device |
US5028761A (en) * | 1989-08-15 | 1991-07-02 | Jamco Corporation | Food service cart with a heating system, and trays and casseroles for such a food service cart |
US5717192A (en) * | 1990-01-10 | 1998-02-10 | Patentsmith Technology, Ltd. | Jet impingement batch oven |
US5434390A (en) * | 1991-09-17 | 1995-07-18 | Turbochef, Inc. | Quick-cookig oven |
US5188020A (en) * | 1991-10-11 | 1993-02-23 | Buchnag Kamal M | Food shelving and cycling system |
US5365038A (en) * | 1992-02-14 | 1994-11-15 | Kabushiki Kaisha Nissei Giken | Covered defroster with a defrosting plate over a latent heat source |
US5235903A (en) * | 1992-03-17 | 1993-08-17 | Tippmann Eugene R | Subatmospheric pressure cook-and-hold steaming oven |
US5496987A (en) * | 1993-06-10 | 1996-03-05 | Siccardi; Enrico | Electric oven, for domestic use, particularly designed to cooking pizzas, cakes and the like |
US5653905A (en) * | 1995-02-16 | 1997-08-05 | Mckinney; Eugene F. | Royalton natural air movement system |
US5724886A (en) * | 1995-05-11 | 1998-03-10 | Restaurant Technology, Inc. | Cooked food staging device and method |
US6358548B1 (en) * | 1995-05-11 | 2002-03-19 | Restaurant Technology, Inc. | Cooked food staging device and method |
US6209447B1 (en) * | 1995-05-11 | 2001-04-03 | Restaurant Technology, Inc. | Cooked food staging device and method |
US6119587A (en) * | 1995-05-11 | 2000-09-19 | Restaurant Technology, Inc. | Cooked food staging device and method |
US5947012A (en) * | 1995-05-11 | 1999-09-07 | Restaurant Technology, Inc. | Cooked food staging device and method |
US5783803A (en) * | 1995-12-20 | 1998-07-21 | Robards, Jr.; Chester F. | Food warming apparatus |
US5900173A (en) * | 1995-12-20 | 1999-05-04 | Prince Castle Inc. | Food warming apparatus |
US6011243A (en) * | 1996-06-27 | 2000-01-04 | Emerson Electric Co | Holding cabinet and method and apparatus for controlling a holding cabinet |
US5934178A (en) * | 1997-01-04 | 1999-08-10 | Heat & Control, Inc. | Air impingement oven |
US5852967A (en) * | 1997-02-03 | 1998-12-29 | Restaurant Technology, Inc. | Food treatment system |
US5919389A (en) * | 1997-03-18 | 1999-07-06 | Sanyo Electric Co. Ltd. | Cooking apparatus including infrared ray sensor |
US6262406B1 (en) * | 1997-05-27 | 2001-07-17 | Turbochef Technologies, Inc. | Compact quick-cooking convectional oven |
US6450085B1 (en) * | 1997-07-18 | 2002-09-17 | Gottfried Riesselmann | Apparatus for cooking dishes by heating |
US6376817B1 (en) * | 1998-10-09 | 2002-04-23 | Turbochef Technologies, Inc. | Compact quick-cooking oven |
US6031208A (en) * | 1998-11-12 | 2000-02-29 | Hatco Corporation | Topless holding bin with side heat source |
US6175099B1 (en) * | 1999-03-31 | 2001-01-16 | Duke Manufacturing Co. | Holding or cooking oven |
US6262394B1 (en) * | 1999-03-31 | 2001-07-17 | Duke Manufacturing Co. | Holding or cooking oven |
US6412403B1 (en) * | 2000-02-29 | 2002-07-02 | Prince Castle, Inc. | Apparatus and method for maintaining cooked food in a ready-to-serve condition using a freestanding cover for food trays |
US20010025842A1 (en) * | 2000-03-07 | 2001-10-04 | Hatco Corporation | Oven device for rapid heating of food items |
US6545251B2 (en) * | 2000-10-26 | 2003-04-08 | Whirlpool Corporation | Cooking oven |
US6539846B2 (en) * | 2001-05-17 | 2003-04-01 | Tecnhos S.R.L. | Apparatus for delivering meals at an appropriate temperature, particularly for use in hospitals |
US20030047553A1 (en) * | 2001-09-07 | 2003-03-13 | Anthony Patti | Multiple panel oven having individual controls for combined conductive and radiant heating panels |
US6658994B1 (en) * | 2002-04-10 | 2003-12-09 | Chromalox, Inc. | Modular assembly for a holding cabinet controller |
US6710308B2 (en) * | 2002-07-31 | 2004-03-23 | Maytag Corporation | Automatic cook sequencing system for multiple ovens |
US20040056015A1 (en) * | 2002-07-31 | 2004-03-25 | Maytag Corporation | Automatic cook sequencing system for multiple ovens with refrigeration unit |
US6878904B2 (en) * | 2003-01-27 | 2005-04-12 | Nicholas G. Verveniotis | Grilling station |
US7307243B2 (en) * | 2003-05-09 | 2007-12-11 | North Carolina State University | Dynamic radiant food preparation methods and systems |
US7279659B2 (en) * | 2004-09-01 | 2007-10-09 | Western Industries, Inc. | Non-food warmer appliance |
Cited By (20)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20060266915A1 (en) * | 2005-05-24 | 2006-11-30 | Ice Cube, Inc. | Tray mold |
US8695489B2 (en) | 2006-04-28 | 2014-04-15 | Restaurant Technology, Inc. | Food staging device |
US20070254079A1 (en) * | 2006-04-28 | 2007-11-01 | Restaurant Technology, Inc. | Food staging device, method of storing foods, and method of making a sandwich |
US20070251667A1 (en) * | 2006-04-28 | 2007-11-01 | Restaurant Technology, Inc. | Food staging device |
US7905173B2 (en) | 2006-04-28 | 2011-03-15 | Restaurant Technology, Inc. | Food staging device, method of storing foods, and method of making a sandwich |
EP1867926A2 (en) | 2006-06-13 | 2007-12-19 | Rational AG | Cooking device with status monitoring of the food products |
EP1867926A3 (en) * | 2006-06-13 | 2008-03-26 | Rational AG | Cooking device with status monitoring of the food products |
US20080019617A1 (en) * | 2006-07-24 | 2008-01-24 | Rasquinha Clarence A | Method of packaging manufactured stone |
US8307761B1 (en) | 2008-06-16 | 2012-11-13 | Low Temp Manufacturing Company | Multi-well food presentation modules |
US9795253B2 (en) | 2008-06-16 | 2017-10-24 | Low Temp Industries, Inc. | Multi-well food presentation modules |
US8661970B2 (en) | 2008-06-16 | 2014-03-04 | Low Temp Manufacturing Company | Multi-well food presentation modules |
FR2939495A1 (en) * | 2008-12-09 | 2010-06-11 | Rational Ag | Cooking apparatus for use in professional kitchen for cooking e.g. baked egg, has display device presenting display sector in cooking chamber, and control device comprising inlet sector in cooking chamber |
US8558142B2 (en) | 2010-04-16 | 2013-10-15 | Restaurant Technology, Inc. | High density universal holding cabinet |
US8450659B2 (en) | 2010-04-16 | 2013-05-28 | Restaurant Technology, Inc. | Control system and method for high density universal holding cabinet |
US8993026B2 (en) * | 2013-05-06 | 2015-03-31 | Sci Direct, Llc | Infrared portable broiler |
WO2021202415A1 (en) * | 2020-04-02 | 2021-10-07 | Automation Tech, LLC | Modular cooking appliance |
US11739942B2 (en) | 2020-04-02 | 2023-08-29 | Automation Tech, LLC | Modular cooking appliance having a hot air oven with a built-in magnetron and a double duty heater |
US11737467B2 (en) | 2020-04-02 | 2023-08-29 | Automation Tech, LLC | Method for cooking in a modular cooking appliance |
US11912465B2 (en) | 2021-01-27 | 2024-02-27 | Duke Manufacturing Co. | Liner for food receiver of food holding apparatus |
USD1005781S1 (en) | 2021-01-29 | 2023-11-28 | Duke Manufacturing Co. | Liner for a food holding well |
Also Published As
Publication number | Publication date |
---|---|
ATE428302T1 (en) | 2009-05-15 |
DE602004020646D1 (en) | 2009-05-28 |
TWI279507B (en) | 2007-04-21 |
CA2541649C (en) | 2012-08-14 |
PL1677607T3 (en) | 2009-10-30 |
EP1677607A4 (en) | 2007-12-26 |
WO2005034633A1 (en) | 2005-04-21 |
ES2325994T3 (en) | 2009-09-28 |
BRPI0415181A (en) | 2007-04-03 |
US7105779B2 (en) | 2006-09-12 |
EP1677607B1 (en) | 2009-04-15 |
US20040069155A1 (en) | 2004-04-15 |
EP1677607A1 (en) | 2006-07-12 |
AU2004279413A1 (en) | 2005-04-21 |
CN1889844A (en) | 2007-01-03 |
TW200516219A (en) | 2005-05-16 |
CA2541649A1 (en) | 2005-04-21 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7105779B2 (en) | Food warming apparatus and method | |
US7446282B2 (en) | Food service apparatus and methods | |
US7227102B2 (en) | Food warming apparatus and method | |
US7328654B2 (en) | Food warming apparatus | |
ES2759325T3 (en) | Automatic rotisserie for variable batch cooking | |
US7468495B2 (en) | Multi-mode convection oven with flow control baffles | |
CN101237779B (en) | Automatic broiler for variable batch cooking | |
US10028608B2 (en) | Oven with steam infusion | |
US6621053B1 (en) | Toaster oven rack | |
MXPA06003955A (en) | Food warming apparatus and method | |
JP3002606U (en) | Heating equipment for cooked food | |
JP4458717B2 (en) | Serving cart |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |