US3340776A

US3340776A - Packaging machine

Info

Publication number: US3340776A
Application number: US455141A
Authority: US
Inventors: Lyle F Shabram
Original assignee: S AND V DEV CO
Current assignee: S AND V DEV CO
Priority date: 1965-05-12
Filing date: 1965-05-12
Publication date: 1967-09-12
Anticipated expiration: 1984-09-12

Description

Sept. 12, 1967 F. SHABRAM 3,340,776

PACKAGING MACHINE Filed May 12, 1965 6 SheetsSheet l INVENTOR.

F: SHABRAM BY 5M 3% E 7 v37 e was A LVLE A TTOR/VE Y5 m MUHHH 6 Sheets-Sheet INVENTOR.

LYLE E SHABRAM BY flL/ ATTORNEYS -N UHHH 4 Sept. 12, 1967 L. F. sHABRAM PACKAGING MACHINE Filed May 12, 1965 Sept. 12, 1967 L. F. SHABRAM PACKAGING MACHINE 6 Sheets-Sheet 4 Filed May 12, 1965 MW a INVENTOR, LYLE E SHABEAM M 4' ATTORNEYS Sept. 12, l fi'i L. F. sHABRAM PACKAGING MACHINE 6 Sheets-Sheet 5 Filed May 12, 1965 FIE 11 INVENTOR. I LYLE F. SHABRAM BY M @5 4 FIE--IU- ATTORNGVS Sept. 12, 1967 L. F. SHABRAM PACKAGING MACHINE Filed May 12, 1965 9 Qt? noc J I88 k 0 H0 0 H00 0 O HZD 6 Sheets-Sheet 6 INVENTOR. LYLE F. SHAB/QAM ATTORNEYS United States Patent Office 3,340,776 Patented Sept. 12, 1967 3,340,776 PACKAGHNG MACHINE Lyle F. Shabram, Seaside, Califi, assignor to S & V Development Company, a partnership Filed May 12, 1965, Ser. No. 455,141 8 Claims. (Cl. 93-8) This invention relates to an automatic packaging machine and more particularly relates to an automatic machine wherein articles are automatically sealed in bags of a thermoplastic film. The invention also relates to a machine which is capable of forming empty bags of a thermoplastic material.

It is an object of the present invention to provide a packaging machine which automatically forms sealed thermoplastic bags around an article.

Another object of this invention is to provide such a machine which operates at a high rate of speed and it is relatively simple and foolproof in operation.

Still another object of this invention is to provide a machine having a continuous action so that the line of packages being formed moves uniformly through the device and is not subjected to a start-stop motion.

Another object of this invention is to provide an automatic packaging machine which automatically adapts itself to form packages of different sizes depending upon the articles to be packaged. For instance, if a number of articles of varying size, such as chicken parts, are to be packaged, the machine will automatically form the right size package for each part.

Still another object of this invention is to provide a machine capable of packaging articles which vary in thickness.

A further object of this invention is to provide a machine Which is capable of producing empty plastic bags which are open at one end and wherein the size of the bags thus produced can be easily varied. Y

A still further object of the invention is to provide a machine which can utilize printed stock and register the package length with the printing.

Another object of this invention is to provide an automatic packaging machine which is adapted to form packages either from a single web of a Ifolded over material or wherein two separate webs can be employed to form the packages.

Other objects and features of advantage of the present invention will be apparent from the balance of the specification.

The machine of the present invention is adapted to form packages of any organic thermoplastic film such as polyethylene, polypropylene, polyvinylchloride, polyvinyl idenechloride and polyester materials. Naturally, the operation of the machine is not limited to the specific plastics mentioned, but may be employed with any thermoplastic film.

In the drawings forming a part of this application:

FIGURE 1 is a side view of a machine embodying the present invention. Shown above the machine are packages in various states of formation.

FIGURE 2 is a plan view of the machine shown in FIGURE 1.

FIGURE 3 is a partial plan view of a machine similar to that shown in FIGURE 2, but employing two side sealing devices and with the light source removed.

FIGURE 4 is an enlarged side view, partly in section, on the line 44 of FIGURE 2 showing a side sealing element.

FIGURE 5 is a top view of the device shown in FIG- URE 4.

FIGURE 6 is a section on the line 6-6 of FIGURE 4. FIGURE 7 is an enlarged sectional view on the line 7-7 of FIGURE 4.

FIGURE 8 is an enlarged section on the line 88 of FIGURE 2 showing the end cut-ofi" and sealing mecha- HISIIIS.

FIGURE 9 is a section on the line 99 of FIGURE 8.

FIGURE 10 is an enlarged section on the line 1010 of FIGURE 9.

FIGURE 11 is an enlarged section on the line 1111 of FIGURE 9.

FIGURE 12 is a diagrammatic view, similar to FIG- URE 8 showing the employment of puller 'bars alternating with sealing bars.

FIGURE 13 is an enlarged perspective view of the end of a puller bar. 1

FIGURE 14 is a schematic diagram of a suitable control circuit for use with the present invention.

The overall operation of the machine can be seen in FIGURES 1 and 2. A thermoplastic film 15 folded upon itself to make a U-shaped structure contains a plurality of articles 17 to :be wrapped. The folded over material first passes through a side seamer and trimmer generally designated 19 where a side seam as at 21 is formed and the package trimmed. The continuous strip then moves under a photocell assembly generally designated 23 which detects the length of package necessary to properly package the article and the cutolf and sealing mechanism generally designated 25 forms a seal between each of the articles and cuts the web apart, forming a plurality of packages 27 each of which contains one of the articles to be sealed. The thus formed packages are discharged as at 29. Turning now to a detailed explanation of the drawings by reference characters, the device includes

side frame members

16 and 18 having links 20 and 22 adjustably supporting a table 24 over which materials being packaged and the packing material passes. The exact height of table 24 can be adjusted by means of screws 26.

Passing over table 24 is a center folded web of a plastic film 15 in which a plurality of articles 17 have been placed. These may be placed in the center fold by hand or by mechanisms forming no part of the present invention.

The center folded sheet first passes through the side sealer generally designated 19 which will now be described in detail. In this connection special reference is made to FIGURES 4 through 7. The film itself acts as a conveyor and is drawn through the machine by the cutoff mechanism 25 which will be later described. The side sealer has four pulleys designated at 28, 30, 32 and 34, each of which has two grooves with a small space separating the grooves. Four belts are trained around the pulleys, namely,

upper belts

36 and 38 and

lower belts

40 and 42.

Guides

41 and 43 push the edges of the film together so that it will be engaged by the belts. The belts are subjected to a substantial amount of heat, as will be later apparent, and are therefore made of a suitable heat-resistant, flexible material such as a silicon rubber. Pulley 34 is driven by belt 44 actuated by pulley 46 which in turn is driven by a spring belt 48 from the mechanism 25, later described. The belts tend to be driven at a linear speed slightly greater than the speed provided by advancing film 15 and the spring belt 48 acts as a slip clutch. However, there is sufficient friction in the system that belt 48 is incapable of driving belts 3640 unless a film is advancing between the belts. Thus, the'speed of the belts is adjusted to the exact feed speed of the advancing film.

Situated between the pulleys is a resistance heating element 50 in the form of a thin ribbon, suita'bly'of nichrome. Element 50 is supported at its ends by

members

52 and 54 which are connected to a source of electricity by the wiring shown so that the element 50 can be maintained at a suitable temperature to cut and seal the plastic material. Further, the support member 54 is preferably spring loaded by spring 56 to keep ribbon 50 taut as it expands. It will be seen that the element 50 is set at a slight angle of the path of travel and as the film 15 advances, the hot element 50 trims a small edge from the side of the film and at the same time the heat causes the cut edges to fuse, forming an edge seal in the space between the belts. This is best shown in FIGURE 7. The trimmed off edge 15A is now discarded; preferably a suction head 45 is used to withdraw the trimmed off portion and to prevent it from clogging the machine.

As described above, the machine is used with a single web of material which is folded upon itself and need only be sealed at one edge. The machine can also be employed with two single webs which are sealed on both edges. If this is done, the modification of FIGURE 3 can be employed where a second edge sealing mechanism 19a is employed at the opposite edge. Sealer 19A is a mirror image of sealer 19.

In order that the side sealer can be set to accommodate varying widths of film or to vary the package size, the entire sealer unit is mounted on a frame member 60 to which is attached block 62 which is threaded and through which screw 64 passes having a knob 66 thereon. The opposite end of screw 64 has a collar thereon (not shown) mounted for rotation in frame member 68. Thus by turning knob 66, one can adjust the side sealer to accommodate any desired width or even move it completely out of the way in case it is desired to make open bags. If a second side sealer 19A is employed, it is mounted in exactly the same manner and its position can be adjusted by knob 66A.

After the side seal has been made as at 21, the continuous strip passes under the photocell unit 23. This consists of a light unit 70 mounted over the path of travel of the web with a photocell 72 mounted under the path of travel. A slit 74 in table 24 admits light to the photocell.

The web of material now passes into the end sealing and severing mechanism 25 which will be described in detail.

In the sealing unit eight pulleys and associated belts are provided to propel sealing bars. Over the path of travel is a pair of

pulleys

76 and 78 on one side and a similar pair of

pulleys

80 and 82 at the opposite side. Under the path of travel are

similar pulleys

84 and 86 at one side of the machine and a similar pair at the opposite side of the machine, only one of which, 88 is visible in the drawings. Each pulley has a deep groove therein to accommodate a V-belt as at 90 which rides with its outer surface substantially flush with the periphery of the pulley, while a second flat belt 92 rests on top of the V-belt and rotates therewith. Each pair of pulleys is provided with a similar pair of belts as shown. The pulleys are driven by means of prime mover 94 through belt 96 and pulley 98 which is keyed to shaft. 100. In addition to carrying the rear discharge pulley 86, and its companion pulley, shaft 100 is keyed to a gear 102 which meshes with gear 104 on shaft 106 to which are attached the

pulleys

78 and 82. Similar gears are used at the opposite side of the machine only one of which, 104A, shows in the drawings. In this manner, the upper and lower pulleys carrying the belts are driven in synchronism. Shaft 100 also carries a pulley 108, which drives the spring belt 48, previously described, and thus the side sealing mechanism.

As can best be seen in FIGURE 8, the upper pairs of V-belts 90 and the fiat belts 92 carry between them the upper sealing bars generally designated 110 and the corresponding lower belts carry lower sealing bars generally designated 112. The upper sealing bars 110 have an outer housing 114 with lugs 116 at each end thereof which fit between V-belts 90 and fiat belts 92. The sealing bars are held in frictional engagement between the two belts and unless restrained, would be carried along with the belts. The fricion between the belts and lugs 116 is such that the bars may be stopped, as is hereafter explained in detail, and held against movement until released. Housing 114 has a slot 118 and each side of the slot is provided 4 with

pads

120 and 124 of a heat-resistant friction material such as silicone rubber. Mounted within the housing 114 is a member 126 carrying electrically insulated arms 128 near the ends thereof between which is mounted a Nichrome ribbon 130. At the extreme end of 126 are arms 132, which extend through slots in the housing 114, and which carry carn follower rollers 134. The member 126 has a friction fit with the housing 114- and will stay in any position in which it is placed and is retained within the housng by the shoulders 136. When the members 126 is resting on the shoulder 136 as is shown at 110A in FIGURE 8, the Nichrome ribbon protrudes slightly beyond the terminal ends of the silicone pads 124. The heating elements 130 are supplied with electricity from rotating

contacts

138 and 140 at opposite sides of the machine. Self-retracting coiled cords as at 142 are employed with all of the heating elements in series so that there is no tendency for the wires to become tangled the sealing bars are carried around by the belts. At each side of the bars 14, upstanding concave V-shaped members 144 are provided, the purpose of which will be later explained. Additionally, at each end of the housing 14 are slots 146 (FIGURE 11) the purpose of which will be likewise later explained.

The lower sealing bars have a much simpler construction than the upper sealing bars and consist merely of a cross member 148 having ends 150 corresponding in function to the lugs 116 on the upper sealing bar, i.e. fitting between the V-belt and the flat belt on the lower pulleys. Pads of heat-resistant silicone rubber 152 having a slot 154 in the center thereof, are provided on the outer surface. Near each end of the bar convex V-shaped members 156 are provided which are in line with and which are complementary to the V-shaped members 144 on the upper bars.

In order to provide proper synchronization, hold back means are employed on both the upper and lower sealing bars so that an upper and lower bar will be released at exactly the right time in synchronism with each other and also to intercept the space between two adjacent articles being wrapped and thus form the seals and the cut-off at exactly the desired place. In order to accomplish this, an upper shaft 160 is provided with a pair of collecting star wheels 162, the collecting star wheels being located adjacent the ends of the sealing bars 110 and in line with the slots 146 at either end thereof. In addition, shaft 160 carries a detent star 164 normally held against rotation by detent 166 which is urged outwardly by spring 168 and which can be drawn in by solenoid 170. As can best be seen in FIGURE 8, a sealing bar 110 is held against forward movement by star 162 operating against the outer ends thereof. The balance of the sealing bars come to rest behind the first sealing bar and are also prevented from forward movement while the belts continue to move. When the detent 166 is now momentarily withdrawn, the first sealing bar can move forward, but as the star wheel 162 rotates, the next tooth catches in the slot 146 (see FIGURE 11) on the sealing bar so that only one bar is released at a time. A lower shaft 160A with a star 162A is similarly actuated by solenoid 170A acting through detent 166A and detent star 164A and is therefore not described in detail.

In order to extend the member 126 and the heating element 130 carried thereby a first pair of cam tracks 158 is provided. It will be noted that the shape of the cam is such that it causes the member 126 to extend slowly and that the cam reaches its lowest point about half way between the pulley shafts. A second pair of cams 184 (only one of which is visible in the drawings) is used to retract the heating elements.

To support the belts and to cause the upper and lower sealing bars to come together with sufficient pressure to grip and propel the web, upper pressure rollers 151 held on bearing support 153 and lower pressure rollers 155 held on bearing support 157 are employed. Both bearing supports are urged toward each other by springs, only the lower springs 159 being shown in the drawings.

The electrical circuitry for actuating the solenoids which release the sealing bars will now be described, particularly with reference to FIGURE 14. Photocell 72 receives light from source 70 and aetuates the solenoid 171 of the SPDT relay 172. A microswitch 174 having an actuating arm 176 is adapted to be contacted by the lower sealing bars as a bar passes the arm and its exact position can be adjusted by moving the switch back and forth in the slot 178. In addition, a SPDT switch 180 is employed in the circuit as well as a time delay relay 182 which closes the contacts 183

actuating solenoids

170 and 170A. Relay 182 produces a single pulse in the solenoids even if current is supplied to it for a substantial period of time. In relay 172 the arm is on the upper contact when there is a light on cell 72 and is on the lower contact when cell 72 is dark. On switch 174 the contact arm is on the upper contact when there is no pressure on arm 176 and on the lower contact when arm 176 is depressed.

If switch 180 is open, it will be seen that switches 172 and 174 are in series and the lower contact of 174 is out of the circuit. As a web containing articles, as is shown in the upper left hand portion of FIGURE 1, passes under the cell, the cell will be dark while the article is-passing over the cell and should microswitch 174 be tripped while the circuit is in this condition, 174 would not have any effect on the relay 182 since there is no operative connection to the lower contact of switch 174. However, as soon as the article has passed under the photocell and the light strikes the photocell by passing through the web in the space between two articles, the relay 182 and thus solenoid 170 and 170A will be tripped, permitting one upper sealing bar and one lower sealing bar to be released. The spacing between the photocell and where upper and lower sealing bars come together is actually the same as the distance from the point of release to the point where the bars come together so that the bars will meet in the space between two articles and make the seal at exactly the desired point between two adjacent articles or the time delay can be adjusted to insure such operation. In the meantime, should a lower sealing bar contact the switch arm 176 and trip switch 174, an additional sealing bar will not be released since the lower contact on switch 174 is now open.

As an upper and lower sealing bar are released, they will be propelled toward each other past the position shown at 110B and 112B and finally engage each other between the two pulleys where the

mating segments

144 and 156 will engage, correcting any minor misalignment between the upper and lower bars. As the upper bar passes over cam 158, cam follower 134 is brought slowly inwardly so that the action is that the web will first be grasped between the

pads

120 and 124 of the upper sealing bar and the pad 152 of the lower sealing bar, propelling the web along. After the pads are in contact and are holding the web firmly, the cam follower 134 still following the cam 158 is driven out of its slot to the position shown in 110A whereupon it enters slot 154 of the lower sealing bar severing the web and heat sealing each end thereof. After this operation is completed, the cam fol- .lower 134 is now engaged by reverse cam 184 so that the sealing ribbon 130 is retracted into the housing 114 while the pads on the upper and lower sealing bars still are in engagement with the web, which has been severed at this point but with the pads still engaging the trailing edge of one package and the forward edge of the next adjacent package. As the sealing bars continue their travel, they disengage each other as the belts pass around the second set of pulleys releasing the completed package to fall in apron 186 where it is discharged as at 29.

If an article is missing from the web or if one merely wishes to make bags, the switch 174 will trip as a lower sealing bar passes over it, causing a pulse to release another set of sealing bars, and so on.

If the switch 180 is in the closed position, it will be seen that the upper contact of switch 174 is effectively shorted out so that relay 182 can be actuated either by arm 176 or by relay 172. This position is used when it is desired to make packages longer than the path of travel of the travel of the sealing bars when in engagement. It will be apparent that with the structure thus far described, the sealing bars serve to pull the web through the machine. It is also obvious that if one attempts to wrap a package longer than the distance between the shafts of the propelling pulleys, that no sealing bars would be in contact with the web and the web would stop. In order to remedy this situation, the propelling bars shown in FIGURE 13 are employed. The propelling bars are quite similar in structure to the sealing bars, except that both the upper and lower bars merely have a padv 188 of a resilient material thereon. Although these bars might also be equipped with the

mating segments

144 and 156 as employed on the sealing bars, this ordinarily is not necessary since the precise alignment required of the sealing bars is not necessary in the case of the propelling bars. In FIGURE 12 there is shown diagrammatically how the propelling bars are employed. In this particular illustration, one propelling bar is employed for each sealing bar although it will be obvious that more than one propelling bar per sealing bar might be employed. Thus propelling bars 188 alternate with sealing bars and 112. In FIG- URE 12 bars 188A and 188B are shown propelling the web through the machine while the sealing bars 110C and 112C are coming into position to seal the package. Bars 110D and 112D have just completed a sealing operation at the leading edge of the package being carried by the bars 188A and 188B. When employing the propelling bars the switch is closed. In this position if there is an interruption of the light beam, the contacts 183 will close. However, even if the cell is dark and relay 172 is on the lower contact, actuation of switch 174 will release the solenoid. Thus, the action in wrapping long packages is that first the light will fall in the space between articles, releasing a pair of sealing bars, the lower sealing bar will then trip switch 174 releasing a pair of propelling bars,

and so on.

When the switch is closed, empty bags can be made since when relay 172 is on the upper contact tripping switch 174 will actuate the circuit. If empty bags are made from a single folded over web, no side seamer would be used, or if bags are to be made of a double web only a single side seamer would be used.

Although it has been assumed that articles in the web are employed to trip the photocell, printed film might be used with the cell set to detect the ditference in light reflecting or transmission characteristics between different portions of the printed web.

It will be apparent to those skilled in the art that many departures can be made from the exact structure herein shown without departing from the spirit of this invention.

For instance, the heating element might be placed in the lower sealing bars rather than the upper sealing bars. Further, the photocell might be operated by reflected rather than transmitted light, particularly if printed bags are used.

Instead of the photocell means, the web might have magnetic printing thereon and magnetic detecting means 7 used to actuate the bar release mechanism.

I claim:

1. A bag-making machine or the like wherein a web of a thermoplastic material is sealed to a matching surface and severed therefrom comprising, in combination:

(a) at least one upper sealing bar and at least one lower sealing bar,

(b) means for propelling said upper and lower sealing bars on either side of a web of thermoplastic materi-al,

(c) means on said sealing bars whereby the sealing bars grip the web and propel it along said path,

((1) means whereby a heated sealing element passes down through one of said sealing bars while the sealing bars are in gripping arrangement with the web,

(e) means whereby said heating element is removed from the proximity of the web while the sealing bars are still in gripping arrangement with the severed ends of the Web, and means whereby the sealing bars are released from the severed portion-s of the web.

2. The structure of claim 1 wherein each of said sealing bars has a gripping pad thereon, each of said pads having a slot near the center thereof, one of said sealing bars having a heating element with means for extending the heating element from the slot in the sealing bar into the slot of the other sealing bar.

3. A bag-making machine or the like wherein a web of a thermoplastic material is sealed to a matching surface and severed therefrom comprising, in combination:

(a) -a plurality of upper sealing bars and a plurality of lower sealing bars,

(-1)) means for propelling said upper and lower sealing bars on either side of a web of thermoplastic material,

(c) a cam follower on each of said sealing bars,

(d) cam means on said sealing bars whereby the sealing bars are urged into engagement with each other and grip the web and propel it along said path,

(e) means whereby a heated sealing element passes down through one of said sealing bars while the sealing bars are in gripping arrangement with the web,

()5) means whereby said heating element is removed from the proximity of the web while the sealing bars are still in a gripping arrangement with the severed ends of the web, and means whereby the sealing bars are released from the severed portions of the web.

4. The structure of claim 3 wherein the propelling means comprises composite be'lts above and below the path of travel of the sealing bars, each of the composite belts including an outer belt and an inner belt with lugs on the sealing bars being held in frictional engagement between the belts.

5. The structure of claim 4 wherein the belts move continuously with detent means for holding the sealing bars against travel, said detent means periodically releasing a single upper sealing bar and a single lower sealing bar.

6. The structure of claim 5 wherein photocell means is employed to releases the bars.

7. A bag-making machine or the like wherein a web of a thermoplastic material is sealed to a matching surface and severed therefrom comprising, in combination (a) a plurality of upper sealing bars and a plurality of lower sealing bars,

(b) a plurality of upper and lower propelling bars,

(c) means for propelling said bars on either side of a web of thermoplastic material,

(d) means on said bars whereby the bars grip the web and propel it along said path,

(e) means whereby a heated sealing and severing element passes down through one of said sealing bars while the sealing bars are in gripping arrangement with the web,

(f) means whereby said heating element is removed from the proximity of the web while the sealing bars are still in gripping arrangement with the severed ends of the web, and means whereby the sealing bars are released from the severed portions of the web, said sealing bars and said propelling bars alternating to move the web.

8. The structure of claim 1 wherein at least one side sealing element is employed, said side sealing element comprising a heated ribbon in the path of travel of the web, said rib trimming an edge ofi the web and heat sealing the severed edge.

References Cited UNITED STATES PATENTS 2,720,246 10/1955 Piazze 93-8 3,122,467 2/1964 Hannon 93-8 ANDREW R. JUHASZ, Primary Examiner.

GERALD A. DOST, Assistant Examiner.

Claims

1. A BAG-MAKING MACHINE OR THE LIKE WHEREIN A WEB OF A THERMOPLASTIC MATERIAL IS SEALED TO A MATCHING SURFACE AND SEVERED THEREFROM COMPRISING, IN COMBINATION: (A) AT LEAST ONE UPPER SEALING BAR AND AT LEAST ONE LOWER SEALING BAR, (B) MEANS FOR PROPELLING SAID UPPER AND LOWER SEALING BARS ON EITHER SIDE OF A WEB OF THERMOPLASTIC MATERIAL, (C) MEANS ON SAID SEALING BARS WHEREBY THE SEALING BARS GRIP THE WEB AND PROPEL IT ALONG SAID PATH, (D) MEANS WHEREBY A HEATED SEALING ELEMENT PASSES DOWN THROUGH ONE OF SAID SEALING BARS WHILE THE SEALING BARS ARE IN GRIPPING ARRANGEMENT WITH THE WEB, (E) MEANS WHEREBY SAID HEATING ELEMENT IS REMOVED FROM THE PROXIMITY OF THE WEB WHILE THE SEALING BARS ARE STILL IN GRIPPING ARRANGEMENT WITH THE SEVERED ENDS OF THE WEB, AND MEANS WHEREBY THE SEALING BARS ARE RELEASED FROM THE SEVERED PORTIONS OF THE WEB.