US3060593A - Clothes drier - Google Patents

Description

Oct. 30, 1962 Filed Aug. 7, 1959 R- A. FLORA ETAL CLOTHES DRIER 6 Sheets-Sheet l 000/1779 air Dry/77g air a4 38 K /36 90881 I00 24 i 0 74 ii-.. 4. l

70 I 68 9e e4 l 82 9a 30 loo INVENTORS 7716/! Attorney Fig. l

Oct 1962 R. A. FLORA ETAL 7 3,050,593

CLOTHES DRIER Filed Aug. 7, 1959 6 Sheets-Sheet 2 INVENTORS Y Raymond A. Flora George. A. Nay/muse Jack W Savage Ralph K. Shewmon The/r Af/omey Oct. 30, 1962 R. A. FLORA ETAL 3,060,593

CLOTHES DRIER Filed Aug. 7, 1959 6 Sheets-Sheet 3 INVE/V TORS Raymond A. Flora George- ';4: Nay/rouse Jack W. Savag'e 4 Ralph .Slwwmon T/reir Afro/nay Oct. 30, 1962 R. A. FLORA ETAL 3,060,593

CLOTHES DRIER Filed Aug. '7, 1959 6 Sheets-Sheet 4 INVENTOR-S Fly, 5 Raymond A. Flora c j George/1. Nay/louse Jack mavage Drying BY Ralph K Skew/non Their florney Oct. 30, 1962 R. A. FLORA ETAL 3,060,593

CLOTHES DRIER Filed Aug. 7, 1959 6 Sheets-Sheet 5 INVENTORS 6 Raymond A. F/ora'= George A; Nay/muse Jack W. Savage Ra/p/l K. Shaw/nan Their Al/omey Oct. 30, 1962 R. A. FLORA ETAL 3,060,593

- CLOTHES DRIER Filed Aug. 7, 1959 6 Sheets-Sheet 6 'l/VVE/VTO/PS Raymond A. Flora George A. Neyhouse Jack W. Savage Ralph K. Siren/man I BY 7 The/r A fforney .nie

3,i 50,593 Patented Oct. 30, 1962 3,060,593 CLOTHES DRIER Raymond A. Flora, George A. Neyhouse, and Jack W. Savage, Dayton, and Ralph K. Showman, Centerville, Ohio, assignors to General Motors Corporation, De-

troit, Mich, a corporation of Delaware Filed Aug. 7, 1959, Ser. No. 832,186 12 Claims. (Cl. 34-433) This invention relates to a domestic appliance and more particularly to an improved drying apparatus.

A major consideration of the appliance industry con cerns the reduction in product size and the standardization of parts. In the manufacture of drying apparatus, the prime moving and air circulating system for the dryer constitutes a severe obstacle to this reduction in size. In the past, it has been disposed primarily in a space beneath the tumbling drum of the drier and has, thus, added to the size of the drier. Further, prior art devices have used belt and pulley systems to transmit power for rotating the tumbling drum and for circulating air through the tumbling drum. This, too, is a space consuming arrange ment. Therefore, these practices and other problems are overcome by this invention in a manner to reduce the over-all size of a clothes drier and to provide a compact prime moving and air circulating system which may be interchangeably adapted to difierent driers.

Accordingly, it is an object of this invention to provide a clothes drier with a prime moving system which mounts in a central portion of the tumbling drum.

It is also an object of this invention to provide a clothes drier which eliminates the need for belts and pulleys in its prime moving system.

A further object of this invention is the provision of a motor for a clothes drier which rotates the tumbling drum from one end of the motor and the air impelling means from the other end thereof.

It is also an object of this invention to provide a prime moving and air circulating system which may be used interchangeably for difierent type driers.

A more specific object of this invention is the provision of an integral unit for a clothes drier which includes a tumbling drum driving means, an impeller driving means and a heater in one compact unit.

Another object of this invention is the provision of a compact unitary prime moving and air circulating system for a forced draft drying system and an induced draft drying system.

A further object of this invention as it applies to a forced draft drying system is the provision of air flow passageways through the motor which are connected to a blower and tumbling drum whereby the motor is cooled by air which then commingles with the drying air to add the motor heat to the heat of drying.

Another object of this invention is the provision of an impeller for a motor driven clothes drier which circulates predetermined pro-rated quantities of drying air through said drier and cooling air through said motor.

A more specific object of this invention is the provision of a duct system for a prime moving and heated air circulating system which provides an insulating air barrier between the heater for said air and the motor of said prime moving system.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein preferred embodiment of the present invention are clearly shown.

In the drawings:

FIGURE 1 is a schematic side sectional view of a drier provided with the prime moving and forced draft system of this invention;

FIGURE 2 is a fragmentary elevational view with parts broken away to show the clothes drying air and motor cooling air housing in accordance with the forced draft form of this invention;

FIGURE 3 is a fragmentary sectional view of the prime moving and air circulating system shown in FIGURE 1;

FIGURE 4 is a fragmentary sectional view of the means for mounting a tumbling drum to the prime moving system of this invention;

FIGURE 5 is a schematic sectional view of a clothes drier provided with a second embodiment of this invention showing an induced draft air circulating system;

FIGURE 6 is a rear elevational view of the FIGURE 5 drier with parts broken away to show the combined motor cooling and clothes drying air fiow duct system of this second embodiment; and

FIGURE 7 is a fragmentary sectional view of the prime 7 moving and air circulating system shown in the induced draft arrangement of FIGURE 5.

In accordance with this invention and with reference to FIGURE 1, a forced draft drying system is set forth for a clothes drying apparatus. A clothes drier Iii is shown which is provided with a rear drum support bulkhead 12, a base portion 14, and a front wall 16. A top panel 18 is included to cover the drier 10 and provide the housing means whereby a control 20 is positioned for any conventional control of the clothes drier. Within the clothes drier 10 is located a tumbling drum 22 which has a rear wall 24 and a front annular closure-26. The annular closure 26 defines a collar 28 which forms an access opening into the tumbling drum 22. The opening 28 is also the means of egress for air circulating through the tumbling drum 22. For admitting air to the tumbling drum, the rear wall 24- includes a plurality of ports 30 which connect with an inlet air flow space or annular heated air chamber 32 between the rear wall 24 of the tumbling drum and the rear support bulkhead 12. An annular seal 34 defines the outer limits of the annular air space 32 and is mounted on the support wall or bulkhead 12 and adapted to seal in a relative rotational fashion against a shoulder 36 at the rear of the tumbling drum 22.

The front wall 16 has an inwardly turned shoulder portion 40 which supports a front port plate 42 having a cylindrical inlet collar or support flange '44 which nests within the drum collar 28 and is adapted to support the drum on a plurality of nylon rubbing blocks (not shown) interposed between the collars 44 and 28. Between the support blocks, a strip of felt sealing material 46 isutilized to prevent leakage from the air flow system. An open ing 48, formed by the shoulder 40 in the front wall 16, isclosed by a door 50- in which a plurality of louvers 52 are stamped to provide for egress of air from the tu'mblingdrum 22. Any suitable seal 49 may be used to minimize air leakage when the drier is'in operation.

The door 50 has a rear panel 54 on which alint collecting housing 56 is aflixed. The housing 56 has a ported rear panel 58 which receives air from the tumbling drum 22. When the door 50 is in closed position as seen in FIGURE 1, an annular seal 60 serves to prevent air from escaping around the edges of the lint collecting housing 56. Within the housing 56, a lint screen 62 is disposed which has a support and removable handle portion 64 which permits removal of the lint screen for cleaning when the door 50 is opened.

The foregoing general construction of a cabinet and drum for a drying apparatus forms'no part of this inven' tion. Thus, to constitute an operable device, there remains to be had only a prime moving system whereby the tumbling drum 22 may be rotated and a flow or current of heated air caused to proceed through the tumbling drum in a clothes drying operation. In the past, this has been accomplished by a motor located in the bottom of the drier and arranged with belts and pulleys to drive the tumbling drum 22 and an air circulating means or blower. The drier of FIGURE 1 is shown with a space 66 beneath the tumbling drum 22 to indicate the waste area which has been occasioned by prior art designs. It is the pur pose of this invention to save this space 66 in a manner to reduce the over-all dimensions of the drier 10 or to free the space 66 for use in another manner.

A compact prime moving and air circulating system 68 is shown generally in FIGURE 1. The system includes a motor 70 having a full speed impeller shaft portion 72 and a reduced speed drum shaft portion 74. To achieve these ends, the motor 70 includes a planetary gear speed reduction segment shown generally at 76. The rear wall 24 of the tumbling drum 22 includes a dished out or inwardly recessed portion 78 which receives the gear reduction housing 76 and a motor mounting housing 80'. It is not necessary that the drum wall be recessed at 78, however, in order to fully avail oneself of the advantages of compactness in this invention, it is desirable to dispose the prime moving system 68 within an area which is otherwise waste space within the tumbling drum. The prime moving and air circulating system 68 includes an impeller shown generally at 82 having a first or motor cooling air stage 84 and a second or drying air circulating stage 86. The impeller 82 is attached in any suitable fashion to the motor full speed shaft portion 72 as by a set screw 83 in a keyway. A heater housing 88 provides the means for covering the heaters 90' and includes inlet openings 92 which directs air from the atmosphere to the impeller 82.

Problems in heat radiation occur with the heaters 90 as close to the motor 70 as seen in FIGURE 1. This invention provides an air barrier 94 interposed between the heaters 90 and the motor 70 as will be explained more fully hereinafter.

In accordance with this invention, the prime moving and air circulating system 68 is adapted to be applied to any drier having a forced draft air flow and a means of support adjacent the tumbling drum. In particular, the motor mounting housing '80 is carried by a support or adapter plate 98 which is spaced from the rear bulkhead by a plurality of spacers 100. However, it should be recognized that the motor mounting housing 80 could be mounted directly on the rear bulkhead 12 of the drier 10. In such a situation, duct work could be provided to connect the ported rear wall 24 of the tumbling drum to the outlet of the blower impeller 82.

The explanation of the air flow system of this invention is facilitated by using solid-line arrows to indicate a clothes drying air flow and dashed-line arrows to indicate a motor cooling air flow. Thus, with reference to FIGURE 1, the drying air flow is created when the motor 70 is energized to rotate the shaft portion 72 and the impeller 82 thereon. Outside air is drawn through the heater housing '88 by way of inlets 92. This air is heated by the heaters 90 and is forced by the impeller stage 86 into the annular space 32 adjacent the rear wall of the tumbling drum. From this point, the heated air is forced through the perforations 30 in the tumbling drum and through the tumbling drum 22 to the outlet collar 28. From this point, the air, which is then moisture-laden, is forced through the lint collecting screen 62 and through the louvered access door 50. At the same time, the motor 70 is cooled by an airflow traversing a path shown in dashed arrows. To do so, the intake duct 96 is caused to direct cool outside air to the motor 70 by the suction created by the first stage 84 of the impeller 82. This motor cooling air which is heated by the operation of the motor 70 then mixes with the air drawn over the heaters 90 and together the combined flows proceed to evaporate moisture from fabric in the tumbling drum. It should thus be seen that the novel air circulating system of this invention not only cools a motor situated in a high temperature area but serves also to utilize the heat of the motor in speeding the drying of the fabric placed within the tumbling drum 22.

The details of the novel prime moving and air circulating system of this invention will now be set forth in connection with FIGURES 2 and 3. The motor 70 is provided with an outer casing 110 in which a plurality of circumferentially arranged air cooling ports 112 is formed. This casing 114) is spaced from the motor mounting to form an annular motor cooling air passageway 115. A segmented or interrupted tenon 114 provides the interchange of air through one end of the motor housing and the passageway 115. Similarly, an end frame 116 at the opposite end of the motor 70 is provided with end frame openings 118 to permit the axial flow of air into the motor housing 110. The motor 7t) is a conventional induction type and includes a stator 120 and a rotor 122 disposed within the stator. A motor speed of 1725 rpm. has been found satisfactory for this invention. The rotor 122 is formed with a plurality of axially directed air passageways 124 which permit the through-flow of air from the end frame openings 118 to the air cooling outlet openings 112 and 114. Attached to the rotor 122 of the motor 70 is a motor shaft 121 which has a keyway portion 122 for lockingly receiving the impeller 82. The opposite end of the motor shaft 121 is formed with gear teeth 125 which act as the driving pinion for the speed reduction gearing unit 76 to effect a rotation of the shaft 74 at approximately 50 r.p.m.

Although the reduction gearing per se forms no part of this invention, the speed reduction is accomplished by a planetary gearing arrangement as follows. The shaft gear 125 drives a first planetary gear 126 and a second planetary gear 127. The planetary gears 126 and 127 revolve on bearing ring portions 128 and 130. In turn, the planetary gears 126 and 127 include shank portions 132 and 134, respectively. The shank portions 132 and 134 are formed with gear teeth which intermesh with a ring gear 136. The planetary gears 126 and 127 rotate about spirally grooved pins which rotate the driven gear or output shaft 74 as the planetary gears revolve. In this arrangement, it is possible to achieve an impeller speed of 1725 rpm. (the synchronous speed of the motor) and an output shaft speed of 50 rpm. (the reduced output speed of the gear reduction unit 76). Suitable oil seals 137 are mounted about the input and output shafts of the speed reduction unit to retain an oil bath therein.

The manner in which the drum 22 is attached to the prime moving system is seen in FIGURES 3 and 4. To attach the prime moving system to the tumbling drum 22, a nut 142 may be utilized. The output shaft 74 is formed with a flat 144 which matches a similar fiat in a reinforcement portion 146 which is secured to the inward recess 73 of the tumbling drum. The bolt 142 is threaded into the end of the output shaft 74 and the drum is thereby rigidly afiixed to the prime moving system 68. As aforesaid, the entire prime moving and air circulating system 68 is affixed to a support bulkhead, such as 12. The bulkhead thus becomes the means for supporting the rear end of the tumbling drum.

The heater housing 88 will be described more fully with reference to FIGURE 2. The housing 88 is formed with a flange 159 which may be fastened as at 152 to the rear bulk-head 1-2. The housing 88 is formed with openings 92 which lie adjacent the heaters 90. Extending from a generally central portion of the housing 88 is a motor air intake duct 96 which is generally cylindrical in shape. Circumscribing the duct 96 is an annular passage 94 which forms a thermal insulating barrier to protect the motor 70. To form the insulating barrier or passageway 94, the housing 88 has an inwardly turned cylindrical wall portion 154 which is reverse-bent to the cylindrical air intake duct 96. At the inwardly directed end of the wall portion 154 are a plurality of circumferentially arranged, generally circular insulating barrier air outlet openings 156. These openings 156 communicate with the inlet side of the second stage 86 of the impeller 82. Thus, when the impeller 82 is rotating, air is drawn through the passageway 94 and the openings 156 to the inlet side of the impeller stage 86. Since the heaters are on one side of the housing wall 154 and the motor 70 is disposed only a short distance therefrom, the cylindrical or annular passageway 94 provides a barrier or cool air during operation of the drier. This barrier effectively insulates the heat of the drier heaters 90 from the motor 7t) and, thus, enhances a long life of trouble-free operation for the apparatus.

The housing 83 is designed to form a heating chamber 39 in which the heaters 96 are disposed. To admit the heated air to the inlet side of the impeller stage 86, the rear bulkhead 12 has an opening 158. This ararngement permits cool air to enter the heater chamber 89 by way of inlet openings 92 and heated air to leave the housing through bulkhead opening 158 to the inlet side of the impeller stage 86.

The impeller 82 is formed with a back plate 160' in which a plurality of openings 162 are formed to permit air flow to the motor 70. The impeller includes a cylindrical bafile portion 164 which lies in closely adjacent spaced relationship to the intake duct 96 and the motor end frame 116. In this manner, motor cooling air flow entering duct 96 is substantially prevented from bypassing the motor 76. Extending from the baffle portion 164 is a radially outer extension 166 of the back plate 16%. The back plate extension 166 supports the first impeller stage 86 as well as the second impeller stage 84, thereby transmitting motor shaft rotation to the impeller. The plurality of impeller blades 84 and 86 are suported respectively at their axially outer edges by an annular support ring 168 and 174). It should be obvious that the impeller 82 could be formed with a single back plate, consolidating portions 16d and 166, by redesigning the housing 83 to permit the impeller stages to move rearwardly. The configuration shown in FIG- URE 3, however, lends itself to a compact arrangement requiring a minimum of drier cabinet space.

The foregoing structure divides the air circulating system into three air flow paths as follows. The drying air flow derives its source of air from the atmosphere from which point the air proceeds through the openings 92 in the heater housing. After being warmed by the heaters 90, the heated air leaves the housing 88 by way of bulkhead opening 158 and enters the inlet side of the first stage 86 of the impeller 82. The impeller stage 86 draws the air from the heater housing and throws it radially outwardly into the annular space 32 adjacent the rear wall of the tumbling drum 22. From this point, the air may proceed through the tumbling drum in a conventional manner, picking up moisture from the dampened clothes therein.

With the motor 70 disposed in such close relation- I ship to the heaters 90, it is necessary to provide a means for cooling the motor. For this purpose, a second air flow is required-a motor cooling air flow. The motor cooling air proceeds also from the atmosphere through a motor air intake duct 96. Since the duct 96 is in line with the openings 162 in the impeller back plate 160, the cooling air flow may enter the motor '70 through openings 118 in the motor end frame 16. The rotor 122 includes the passageways 124 through which the cooling air proceeds to the outlet end of the motor 70, namely, the circumferentially arranged series of ports 112 and the segmented tenon 1 14. As the cooling air leaves the motor, having picked up the heat therefrom, the air enters the surrounding cooling air passageway 115 which surrounds the motor casing 11%. This passageway 115 connect through an opening 117 in the adapter plate 98 to the inlet side of the impeller second stage 84. The impeller second stage also connects with the annular space 32 adjacent the rear wall of the tumbling drum.

A third air flow channel is utilized in this invention to provide an insulating barrier between the heaters 90 and the motor '70. The insulator barrier passageway 24 is opened to the atmosphere and receives air therefrom whenever the impeller first stage 86 is in operation. The relatively cool atmospheric air is drawn through the cylindrical or annular passageway 94 and the openings 156 at one end thereof to the inlet side of the impeller stage 86. This insulating air is warmed as it proceeds along the wall 154 of the heater housing 88. The air joins the heated drying air proceeding from the housing 88 by way of opening 158 and is thrown into the annular space 32. It will be noticed that all three air flows commingle or mix at the outlet of the impeller 82. In this way, the efficiency of the drier is improved in the fact that the heat loss of the motor is added to the heated air being used to dry the clothes. This novel three-flow air pass has been found to maintain the motor 719 in an exceptionally cool operating condition in spite of its proximity to the heaters 96 and its generally confined location within the drying apparatus.

The foregoing embodiment is adapted to a pusher type or forced draft system wherein the air flow is pushed through the tumbling drum. However, certain drier manufacturers prefer the induced draft air flow system wherein air is pulled or sucked through the tumbling drum. The novel combination prime moving and air circulating system of this invention may be equally well adapted to the induced draft system in accordance with the concepts of this invention as described next following.

Reference may now be had to the FIGURES 5, 6 and 7 for a complete description of the induced draft type dried adapted for use with this invention. Reference numerals for identical parts in both the forced draft and induced draft arrangements Will be the same. An induced draft drier 260 is provided with a front wall 202 having an access opening 204 closed by an imperforate door 206-. A support bulkhead 268 is interposed between a top wall 210 of the drier and a bottom support 212. Disposed within the drier 200 is a tumbling drum 22. As in the first embodiment, a seal 34 may be utilized to provide the or define the outer limits of an annular space 218 between the bulkhead 208 and the rear wall 24 of the tumbling drum. Also as with the first embodiment, a dished out or recessed wall portion 78 is formed to receive the prime moving system and induced draft air circulating arrangement shown generally at 224. The tumbling drum 22 has a front access collar 28 which is supported by a front port plate baffle 42 carried by the front wall 202 of the drier. The door 206 carries a perforated bafile 229 which deflects clothing during the tumbling operation from the area between the tumbling drum and the door 206. The front port plate 42 is formed with a plurality of arcuately arranged openings 236 which open into a front duct 232. Disposed beneath the front duct 232 is a lint collecting chamber 234 in which a lint collector 236 is adapted to be slidably removed by a handle 238. The lint collecting housing has an outlet 240 which connects to a conduit 242 leading to a drying air return duct 244 in the air circulating system.

The prime moving and air circulating system arrangement 224 includes a motor 246, a motor mounting housing 80, a gear reduction housing 76, a blower housing 252 and an impeller 254 rotatably mounted to the motor 246 within the blower housing 252. The blower housing 252 has an opening 256 which is interconnected with an outlet 258 from the intake or drying air return duct 244. The motor housing has a flange 260 which may be fastened in any suitable manner to an opening 261 in the rear bulkhead 268, the housing and the gear reduction extending into the inwardly bulged portion '78 of the tumbling drum.

For heating the air, a heater of any conventional type 262 may be disposed in a housing 265 adjacent an inlet 264 in the support bulkhead 268. Thus, atmospheric air enters the open rear of the drier 200, proceeds through an opening 263 in the heater housing 265 and enters an annular space 266 between the bulkhead and the perforated rear wall 24 of the tumbling drum. Air is pulled through the tumbling drum and the front batllle 229 at which point it enters the front duct 232. Air is filtered within the lint collecting housing 234 and returns to the intake duct 244. This duct 244 leads to the inlet of the blower 252 from which it is exhausted in any suitable manner to the atmosphere. In FIGURE 5, the drying air flow is shown by a solid arrow, whereas the cooling air flow for the motor 246 is shown in a dashed-line arrow. Reference will now be had to FIGURES 6 and 7 for a detailed description of the combination prime moving and induced draft air circulating system of this in vention.

The prime mover or motor 246 in the induced draft arrangement is essentially the same as the motor 74} set forth in connection with the forced draft drying system. In the induced draft system, however, the motor casing 110 is designed for air circulation in the following manner. At one end of the motor casing, an open end frame 116 includes a series of radially arranged ports 11% to permit outflow of cooling air from the motor 246. At the opposite end of the motor, a series of circumferentially arranged ports 112 are arranged in the casing 11ft along with a segmented tenon 114. The combination of the ports 112 and of the spacing allowed by the segmented tenon 114 permit inflow of air to the motor 246 from a passageway 270 surrounding the motor casing 110 within the motor mounting shell 80. Within the motor 246, the rotor 122 is provided with a plurality of generally cylindrical passageways 124 to allow the through flow of air in the motor. Thus, cooling air flow is induced by the impeller 254 to enter the clothes drier cabinet through an opening 272 in the back of the drier. This air channels in any suitable manner around the blower 252 and duct 244 in the area between the rear bulkhead 208 and the rear of the drier cabinet and proceeds toward the annular passageway 276 immediately adjacent the motor casing 116. The ports 112 in the motor casing as well as the openings facilitated by the segmented tenon permit ingress of cooling air to the internal parts of the motor. Passageways 124 in the rotor guide the air through the central part of the motor where the motor heat is entrained and from which point the heated air is carried from the motor casing by way of outflow ports 118 in the end frame 116. At this point, the motor cooling air enters the blower housing 252 and is expelled or exhausted from the drier.

In this second embodiment, the motor 246 is adapted to support both the upright return duct and the blower housing. The return duct 244 for the clothes drying air lies in juxtaposition to the blower housing 252. More particularly, the blower housing 252 is comprised of a scroll portion which terminates in an outlet 274. Fur-. ther, the blower housing has an inner wall 276 and an outer wall 278. The inner wall 276 of the blower housing is formed with the opening 256 from which project a plurality of attachment tabs 282. In juxtaposition to the rear wall 276 of the blower is the front wall 284 of the return duct 244. Similar, but slightly shorter, tabs 286 extend from an opening 258 in the duct wall 284. In this fashion, the tabs may be aligned in juxtaposition to secure the blower housing 252 to the front duct 244. Further, the outer extension of the tabs 282 receive one end of a through bolt 290 which serves also to assemble the motor 246. A spacer 292 is effective to hold the combination duct and blower housing in correctly spaced alignment with the end frame 116 of the motor. It should be noted that the end frame 116 is spaced a short distance from the front wall 284 of the system intake duct 244. In this fashion, the induced draft set up by the ing housing 80 in the second embodiment.

impeller 254 draws motor cooling air satisfactorily through the motor 246 as well as clothes drying air from the return air duct 244. However, it is within the purview of this invention to place the end frame of the motor 246 in coplanar relationship with the blower housing opening 256, thereby to draw two completely separated paths of air into the blowernarnely, the cooling air flow through the motor 246 and the drying air flow from the duct 244 and, more particularly, through the spaces 294 interspersed between the tabs Therefore, by regulating the proximity of the motor end frame 116 to the blower opening 256, the amount of cooling air drawn through the motor may be changed. This is important for it permits the system to be adjusted to obtain the proper operating temperature for the motor 246. As a practical matter, the spacer 25 2 may be lengthened to reduce air flow through the motor and shortened to increase the air supply.

The motor shaft 121 is adapted to support a hub 296 on the impeller 254. The impeller 254 differs from its counterpart in the first embodiment in that only a single stage impeller is utilized. Therefore, a back plate 293 is fixed to the hub 2% and carries at its outer limits, a plurality of generally radially directed impeller blades 255. These blades 255 are connected at their axially inner ends by an annular ring 299. Any suitable set screw Stltl may be used in conjunction with a fiat on the motor shaft to secure the impeller 254 to the motor shaft 121.

In operation, the motor 246 may be energized in any suitable fashion. Upon energization, the motor will be effective to rotate the impeller 254 at the synchronous speed of the motor, generally 1725 rpm. At the opposite end of the motor, the adaptation of the reduction gear unit '76 is effective to rotate the tumbling drum at approximately 50 rpm. Air flow will be induced through the tumbling drum 214 by way of the heating chamber 265. This air will 'be heated at this point by the heaters 262 carried through the tumbling drum 22 and the lint filtering arrangement at 234. The return duct 244 will draw the air from the front of the tumbling drum and upwardly toward the blower housing 252. The moistureladen air will enter the blower housing through the opening 25!; in the front Wall 284 of the duct. The areas between the support tabs 282 and 286 provide passageways circumscribing the end frame of the motor 246 whereby the drying air may enter the blower housing 252. Simultaneously, air for cooling the motor will be drawn into the rear of the drier around the blower housing 252 and the rear duct 244. This air will channel toward the motor 246 through the passageway 270 interposed between the motor and its mounting housing 80. After threading its way through the motor, the air, then heated, will commingle with the returned moisture-laden drying air and will be exhausted from the drier in any conventional manner. It should be understood that the blower outlet 274 may be connected to suitable ductwork (not shown) for selective exhaust from any part of the drier cabinet. Further, the blower may be connected to a condenser whereby the system of this invention may be adapted to a recirculating air type drier.

It should now be seen that an improved compact combination prime moving and air circulating drying system has been provided which is adaptable to both forced draft driers (system 68 of FIGURES 1, 2 and 3) and induced draft driers (system 224 of FIGURES 5, 6 and 7). It should be obvious that the structural details of this arrangement could be modified within the purview of this invention. For instance, the bulkhead utilized for supporting the combination prime moving and blower system could be formed or drawn to replace the mount- Of major importance is the fact that the motors 70 or 246 must be securely fastened to a stationary bulkhead in the drier which is capable of supporting the tumbling drum at its rear wall and segregating the motor cooling air flow from the drying air as described hereinbefore. The foregoing embodiments have been recited merely as convenient adaptations of this invention to two of the more common clothes drying systems. This invention permits a unitary prime moving and air circulating system to be designed and built separate from the drier cabinet structure itself. The first embodiment has the advantage of combining the motor heat with the drying air to improve the efficiency of the drier. The compact nature of this invention frees a substantial area otherwise devoted in prior art driers to the motor, blower, belts and pulleys. This added space may be used to reduce the size of the drier or to house certain optional features in conjunction with a drier. This invention also includes a two-stage impeller arrangement which may be selectively proportioned for the desired amount of air flow through both the motor for cooling and the heaters for drying. Of inventive significance also is the selective positioning of the motor of the second embodiment within the return duct adjacent the inlet to the blower housing to permit a selective adjustment of air through the motor for cooling. With the above and other detailed characteristics of this invention, any type drying situation may be accommodated in a manner to maintain the motor in a cool operation condition. In addition to the advantages of compactness, experience has shown that the motors of this invention may be adjusted to run cooler than motors in the conventional type drier systems which are spaced a greater distance from the heating elements Thus, the teachings of this invention have advanced the drier art in the areas of interchangeability, compactness and extended motor life.

While the embodiments of the present invention as herein disclosed constitute preferred forms, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. A unitary prime moving and air circulating system for a clothes drier having a tumbling drum and a support bulkhead comprising, a motor having a high speed shaft portion and a reduced speed shaft portion, means for connecting said tumbling drum to said reduced speed shaft portion, said motor having a casing, means in said casing forming an air passageway through said motor, a motor mounting housing having a flange connected for support to said bulkhead, an air circulating means having a drying air inlet and an impeller connected to said high speed shaft portion, said impeller having a first and second stage, means forming an enclosure adjacent said air circulating means and connected to said tumbling drum, said enclosure being connected to said air passageway through said first impeller stage and to said drying air inlet through said second impeller stage, whereby when said impeller is rotated at said high speed and said drum is rotated at said reduced speed, a motor cooling air flow is induced through said air passageway by said first impeller stage and a clothes drying air flow is forced through said tumbling drum by said second impeller stage.

2. A unitary prime moving and air circulating system for a clothes drier having a tumbling drum and a support bulkhead comprising, a motor having a high speed shaft portion and a reduced speed shaft portion, means for connecting said tumbling drum to said reduced speed shaft portion, said motor having a casing, means in said casing forming an air passageway through said motor, a motor mounting housing having a flange connected for support to said bulkhead, an air circulating means having an inlet opening and an impeller connected to said high speed shaft portion through said opening, a conduit adjacent said air circulating means and connected to said tumbling drum, said conduit having afirst aperture connected to said air passageway and a second aperture to said inlet opening of said air circulating means, whereby when said impeller is rotated at said high speed and said drum is rotated at said reduced speed, a motor cooling air flow is induced through said air passageway in one manner and a clothes drying air flow is induced through said tumbling drum in another manner.

3. A unitary prime moving and air circulating system for a clothes drier having a tumbling drum and a support bulkhead comprising, a motor having a high speed shaft portion and a reduced speed shaft portion, means for connecting said tumbling drum to said reduced speed shaft portion, said motor having a casing, means in said casing forming an air passage for cooling said motor, a motor mounting housing having a flange connected for support to said bulkhead, an air circulating means having a heated air inlet and an impeller connected to said high speed shaft portion, means forming an enclosure adjacent said air circulating means and connected to said tumbling drum, said enclosure having one section connected to said air passage and another section to said heated air inlet, whereby when said impeller is rotated at said high speed and said drum is rotated at said reduced speed, a motor cooling air flow travels through said air passageway in one manner and a clothes drying air flow travels through said tumbling drum in another manner.

4. In combination with a tumbling drum for an induced draft drying apparatus, said drum having an air inlet and an air outlet, a prime moving and drying and cooling air circulating system comprising, a motor having a high speed shaft portion, a speed reduction unit drivably connected to said motor, and a motor cooling passageway through said motor having a passageway inlet connected to a source of cooling air relatively cooler than the drying air and a passageway outlet, said tumbling drum connected to said speed reduction unit, a blower housing having inlet means connected to said passageway, impeller means in said housing connected to said high speed shaft portion, and a duct connecting said drum air outlet and said blower housing inlet means in series fiow relationship, said duct having an opening therein adjacent said impeller for receiving at least a portion of said motor into said duct and closely engaging said portion between said passageway inlet and said passageway outlet, thereby to permit cooling air flow through said motor cooling passageway.

5. In combination with a tumbling drum for an induced draft drying apparatus, a prime moving and air circulating system comprising, a motor having means for operating a relatively high speed shaft and a relatively low speed shaft, said motor having a cooling air passageway therethrough, said tumbling drum connected to said reduced speed shaft for rotation therewith, an impeller connected to said full speed shaft for rotation therewith, and means forming a duct connecting said tumbling drum and said impeller in series flow relationship, said duct having an opening therein connected to said cooling air passageway and adjacent said impeller, whereby said motor may extend into said duct through said opening in a manner to induce air flow through said cooling air passageway.

6. In combination, a clothes drier comprising, a tumbling drum having a recess, a drier air circulating blower adjacent said recess and in air flow relationship with said drum, a motor between said drum and said blower and having a relatively slow speed shaft directly connected to said drum in said recess for rotating said drum and a relatively high speed shaft axially in line with said slow speed shaft and connected to said air circulating blower for operating said blower to direct an air flow through said drum, and means including a by-pass duct through said motor and connected to said blower for cooling said motor during operation of said drier.

7. In combination, a clothes drier comprising, a tumbling drum, a dried air circulating blower in primary air flow relationship with said drum, a motor between said drum and said blower and having a relatively slow speed shaft directly connected to said drum and a relatively high speed shaft connected to said air circulating blower, and means for cooling said motor during operation of said drier, said cooling means including a secondary air flow passage through said motor and connected to said blower.

8. A clothes drier comprising, a cabinet, a tumbling drum in said cabinet, said drum having a perforated rear wall and a front access opening, said front access opening being in communication with the atmosphere, said perforated rear Wall having an inwardly directed mounting housing, means for rotating said tumbling drum and for initiating a stream of air through said tumbling drum to said front access opening, said rotating means having a first speed reduction portion connected to said inwardly directed housing for rotating said drum and a second portion, and a two-stage impeller driven by said second portion, said rotating means defining an air passage therethrough connected to one stage of said impeller, and said cabinet having a conduit connecting said second-stage impeller and said perforated rear wall of said drum, Whereby cooling air is circulated through said rotating means and drying air is circulated through said tumbling drum after mixing with said cooling air.

9. A prime moving system for a drying apparatus having a tumbling drum and heating means comprising, a prime mover having a speed reduction portion and a synchronous speed portion, means for directly connecting said tumbling drum to said speed reduction portion for rotation therewith, and impeller means connected to said synchronous speed portion and to said tumbling drum and said prime mover, said impeller having a first and second stage, said second stage being connected in series flow relationship with said heating means and said tumbling drum to direct a stream of drying air through said tumbling drum and said first stage impeller being connected in series flow relationship with said prime mover and said atmosphere to direct a stream of cooling air through said prime mover.

10. A forced draft air circulating system for a drying apparatus having a motor and a heating means, a housing for said heating means, a motor cooling air intake duct for said motor, said housing and said duct forming therebetween an insulating air barrier conduit, said motor having a shaft and an air flow passageway through said motor, an impeller carried by said shaft having a first relatively small impeller portion and a second relatively large impeller portion, said first impeller portion being in series flow relationship with said motor air passageway and said motor cooling air intake duct, and said second impeller portion being connected to said heater housing and said insulating air barrier passageway, and means for connecting both of said impeller portions to said tumbling drum, whereby the heat of said motor and said heating means are impelled in mixed fashion to said tumbling drum.

11. A drier comprising, a tumbling drum, a heater, a motor having a cooling channel and adapted to rotate said drum, a blower having an outlet in series flow relationship with said drum, a first blower inlet connected in air flow relationship to said cooling channel and a second blower inlet connected in air flow relationship to said heater, and impeller means in said blower operated by said motor, said impeller means having a first stage connected to said first blower inlet and a second stage connected to said second blower inlet for directing predetermined air fiows through said channel and past said heater into mixing relationship at the outlet of said blower.

12. In combination, a drier comprising, a drum, a drier air circulating blower in primary air flow relationship with said drum, prime mover means between said drum and said blower and having a relatively slow speed shaft directly connected to said drum and a relatively high speed shaft connected to said air circulating blower, and means for cooling said prime mover means during operation of said drier, said cooling means including a secondary air flow passage through said prime mover means and connected to said blower.

References Cited in the file of this patent UNITED STATES PATENTS 1,935,211 Krohn Nov. 14, 1933 2,050,180 Hurxthal Aug. 4, 1936 2,589,284 ONeil Mar. 18, 1952 2,736,826 Hoover Feb. 28, 1956 2,841,723 Corbett July 1, 1958

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