US3026628A - Drying system for dishwashers - Google Patents

Description

w. E. BERGER, sR., ETAL 3,026,628

DRYING SYSTEM FOR DISHWASHERS March 27, 1962 3 Sheets-Sheet 1 Filed Aug. 7, 1956 INVENTORS WILLIAM E. BERGER SR. BYEDWARD C. LEVIT aw 4/ M ATTORNEYS March 27, 1962 w. E. BERGER, sR., ETAL 3,026,628

DRYING SYSTEM FOR DISHWASHERS 5 Sheets-Sheet 2 Filed Aug. 7, 1956 a n. lflFLunf m k L L INVENTORS WILLIAM E. BERGER SR. BY EDWARD C. LEVIT ATTO RN EYS March 27, 1962 w. E. BERGER, sR., ETAL 3,026,628

DRYING SYSTEM FOR DISHWASHERS Filed Aug. 7. 1956 3 sheets-sheet 5 INVENTORS WILLIAM E. BERGER SR.

EDWARD C. LEVIT ATTO RN EYS Unite States The present invention relates to improvements in domestic type dishwashers and particularly to an improved mechanism for drying dishes by evaporating the moisture from the surfaces of said dishes after they have been washed.

Provisions have heretofore been made for drying dishes after they have been washed in the domestic automatic type dishwasher. In this type of washer the dishes are usually placed in a closed tan-k whereupon they are subjected to a series of washing and rinsing treatments wherein jets or streams of water are sprayed against the dish surfaces with the streams being sequentially varied with the addition of soap or detergent and with a variance in temperature. The final step usually applies a hot clear rinsing fluid to rinse the soaps and detergents from the surface thereof. Drying is frequently accomplished by permitting the moisture to evaporate through normal evaporative processes from the surfaces of the dishes. The dishwasher is then often opened to permit a circulation of room air since the air within the dishwasher will rapidly become saturated with moisture and the dishes will not dry. These processes are accompanied by numerous disadvantages in that the drying process used heretofore have taken a considerable length of time, and if the dishes are needed immediately, they must either be used in their wet state or must be removed and dried with a towel. Further, the housewife must tolerate the filled dishwasher in the kitchen for an extensive period of time until the dishes are dry and then return to the dish handling operation at some later time to stack the dishes on a cabinet shelf. If the dishwasher is opened the dishes are subjected to such foreign materials as may pass into the dishwasher interior from the air in the room including dust, various odors, insects and the like.

Other disadvantages are encountered in that frequently the dishes do not become completely dry since once they have cooled the evaporative process is greatly slowed and dishes having recessed interiors, such as cups and glasses, frequently will be very slow in drying. Evaporative processes have also not been completely satisfactory in that moisture is discharged into the room air. The dishwasher is usually used in the kitchen and this room frequently has an abundance of moisture from cooking processes and other operations in any event. Thus, the addition of more moisture is particularly undesirable.

One of the objections to enforced drying systems is that the moisture being evaporated from the dish surfaces emerges from the dishwasher as steam, and is quite visible to the operator, especially when it strikes the cooler air of the surrounding room. This is especially disturbing to the housewife who realizes that such concentrations of steam can damage materials in the household and the presence of a fog or steam in the air is objectionable from many view points.

Accordingly, it is among the objects of the invention to avoid the difiiculties and objectionable features above referred to and to present an improved mechanism for drying dishes within an automatic dish washer after they have been washed.

Another object of the invention is to provide a mechanism which will provide a very rapid drying of the dishes Within the dishwasher and which will dry them automatically after they have been washed.

'atent t 3,626,628 QQ Patented Mar. 27, 19fi2 Another object of the invention is to provide a mechanism in combination with an automatic dishwasher which will insure that the dishes will be absolutely dried and will insure drying even the difficult hollow concave dishes, such as cups or deep glasses and the like.

A still further object of the invention is to provide a dish drying system to be used in combination with an automatic dishwasher wherein it is unnecessary to open the dishwasher at the end of the washing operation and it is unnecessary to subject the dishes to the effects of foreign elements in the air of the room.

An additional feature of the invention is to provide a dish drying system for use with an automatic dishwasher which will not cause a sudden increase of the moisture content of the air of the room so as to steam the windows and cause other unpleasant on undesirable effects.

Another object of the invention is to provide an improved means for condensing the moisture from the air which is used for drying dishes although discharging the drying air and an improved means for disposing of the condensed moisture.

A still further object of the invention is to provide an improved dishwashing system which is capable of automatically drying the dishes and which will enable reduction of the amount of steam discharged into the surrounding air during the time the dishes are being dried.

Another object of the invention is to provide a dish drying system which will circulate a drying air through the dishes to discharge the air into the surrounding atmosphere and will reduce the relative humidity of the discharged air.

A further object of the invention is to provide a dish drying system for an automatic dishwasher wherein the drying air is discharged into the room and the visible steam or fog issuing from the dishwasher is avoided.

Other objects and advantages will become more apparent from the following specification and claims which present a complete disclosure of the preferred embodiment of the invention taken in connection with the appended drawings in which:

FIGURE 1 is a front elevational view of the drier taken in vertical section through the center of the machine to illustrate the interior construction of a dishwashing machine of the type which is capable of utilizing the advantages and features of the present invention;

FIGURE 2 is a plan view taken in horizontal section with parts removed to illustrate the interior of the dishwasher tank for purposes of showing the path of air circulation therein and the elements which cause the circulation;

FIGURE 3 is a side elevational view taken in vertical section with parts removed and illustrating the interior construction of a dishwasher employing the features of the invention;

FIGURE 4 is a sectional view taken along line IV-IV of FIGURE 3 and illustrating the interior construction of the moisture condenser;

FIGURE 5 is an enlarged vertical fragmentary sec tional view taken through the door of the drier and illustrating an alternative embodiment of the condensing mechanism for the dish drier;

FIGURE 6 is a vertical sectional view taken through the dishwasher to illustrate an alternative form of drying system;

FIGURE 7 is a sectional view taken along line VlI- VII of FIGURE 6 and shown diagrammatically;

FIGURE 8 is an enlarged side elevational view shown in schematic form to illustrate a variation of the embodiment of FIGURE 6; and,

FIGURE 9 is an enlarged detailed view of the fan assembly for directing the drying and mixing air through the washer system.

While the present disclosure illustrates and describes the features of the invention as being used in combination with a preferred type of automatic domestic type dishwasher, it is to be understood that many features of the invention may be used to advantage in combination in other types of installations, although the invention is shown in the preferred embodiment as enjoying particular utility in the combination shown.

The dishwasher shown represents the type known to the art which is used in a domestic household for purposes of washing the dishes used by a family. The dishes are first scraped, then stacked in the dishwasher whereupon the dishwasher, through an automatic cycling arrangement, subjects the dishes to treatment by a cleansing fluid. At the end of the treatment, the dishes are dried by the controlled evaporation of the fluid from the heated dishes.

The washer is housed in a cabinet which encloses the operational elements of the machine to protect the operator and to present an attractive appearing appliance. Within the cabinet 10 is a tank 12, which for the purposes used, is watertight and contains the dishes during the time they are subjected to treatment by the cleansing fluid, thereby creating a treatment zone for the dishes.

For purposes of supporting the dishes within the treatment zone, a rack 14 is provided which is preferably constructed in such a manner so as to have slots as the sides for holding flat dishes 16, such as plates and saucers in upright position and having pockets or other supports better adapted to holding deep hollow dishware, such as cups and glasses, at the center portion 18. This construction of the rack is significant since it insures a positioning of the dishes in cooperation with the path of circulation of drying air which is controlled by operational elements later to be described. The positioning of the hollow dishware 18 at the center of the rack also insures that these diflicult to clean dishes will be Subjected to intense cleansing action in accordance with the dish fluid treatment arrangement illustrated.

For spraying or cleansing the dishes a pair of rotating spray arms 20 and 22 are employed and these spray arms are mounted at their centers to rotate in a common horizontal plane. The spray arms 26 and 22 are shown in FIGURE 1, but omitted from FIGURES 3 and 6 to more clearly show the heating element 122. The spray arms so positioned so that they will overlap at their center and provide a zone of double treatment over which is positioned the deep hollow dishes. These spray arms have upwardly extending nozzles 24, which may be arranged at an angle so that the reaction of the stream issuing therefrom causes a rotation of the arms.

To insure that the arms will not strike each other and interfere in the common overlapping zone between them, they are mechanically linked to keep them rotating in the proper phase relationship. For this purpose, each of the spray arms carries bevel gears 26 and 28 and small bevel pinion gears 30 and 32 are in mesh with the bevel gears. These pinion gears 30 and 32 are mounted on a cross shaft 34 which mechanically links the two bevel gears 26 and 28 to insure the synchronous non-interfering rotation of the two spray arms 20 and 22 at the same speed and in the proper phase relationship. The spray arms are supplied with fluid through hollow supply pipes 36 and 38 and are rotatably mounted at the tops of these pipes. The pipes join in a T, shown at 40, which connects to a diverter valve 42 receiving pressurized water from a pump 44. The diverter valve 42 is controlled to direct the supply of cleaning water either to the two spray arms 20 and 22 or to direct the water up through the pipe 46 where it passes upwardly to be channeled into a rotating spray tube 48 which sprays jets of water onto the top of the dishes. The diverter valve is employed in order that a maximum pressure can be given to each set of spraying elements. a

Water is supplied to the diverter valve 42 from the pump 44 drawing from a sump 50 which is located at the base of the inclined floor 52 of the tank 12. The washing and rinse water is admitted to the tank generally through a water inlet line 54 leading into the tank through a connection which is not shown. The water inlet line 54 connects to the hot and cold water supply lines of the household and may also connect to a heater booster tank 56 to obtain water of very high temperature. The pump 44 draws water from the sump 50, into which the fluid drains from the dishes and from the tank 56. The Water enters the pump through an inlet pipe 58 leading from the sump to the eye of the pump. A screen 60 over the pipe 58 prevents foreign materials, such as food particles, from being recirculated through the spray system and possibly clogging the nozzles. The pump 44 is driven by a motor 62 through a shaft 63 (FIGURE 3).

For purposes of draining the dishwasher at the end of the dishwashing operation, the water passes downwardly from the sump 50 into a drain pump 64- which carries a pulley 66 over which is threaded a belt 68 driven by a pulley 70 carried on a drive motor 72. The drain pump 64- discharges through a pipe 74 to a suitable household drain line to discharge the water and food particles.

For purposes of loading and unloading dishes from the dishwasher, the front of the cabinet is opened by a door 76 which is hingedly mounted at its base and is capable of being swung between an open position, as shown in the dotted line position of FIGURE 3, and a closed position, as is shown in the solid line position of FIGURE 3. The door 76 carries tracks 78, FIGURE 3, which may be extensions of the tracks, shown at 80 and 82 in FIGURE 1, within the tank. The tracks support rollers 84 and 86 on the dish rack 1-4 which permit the dish rack to be rolled in and out of the tank when the door is in open position. To load the rack with the door open, the dish rack is drawn outwardly to the dotted line position of FIGURE 3 and filled with dishes whereupon it is pushed back into the tank on the tracks. The door is moved to closed position and the dishwasher is ready for operation. With the present arrangement, the door is then left in a closed position and need not be opened until the dishes are again used since the dishwasher will automatically dry the dishes within the tank and will store them, acting as a cabinet, protecting them from the dust, dirt and foreign materials in the air. In fact, since the dishwasher is substantially a sealed enclosure, it will protect the dishes much better than the usual kitchen cabinet and therefore the present arrangement enables the dishwasher to perform an important additional function; that of being a storage cabinet, thereby increasing its utility as a kitchen appliance.

As is shown in FIGURES 2 and 3, for purposes of drying the dishes, a forced circulation of heated air is moved through the interior of the dishwasher tank 12 to rapidly and effectively dry the dishes. Air is admitted through a pair of inlet openings 88 and 90 which lead into the dishwashing tank at the rear corners of the tank adjacent the floor 52 of the tank. The air must then circulate across the floor 52 of the tank in the path illustrated by the arrows 92 and 24. The two streams of air 92 and 94 meet at the center of the tank, whereupon they impringe on each other and are deflected upwardly, as shown by the arrows 96 in FIGURE 3. This insures that the air will pass upwardly into the glasses and cups 18 which are situated at the center of the dishwasher by the design of the supporting rack 14. Afterthe air is passed upwardly, circulating into the interior of the hollow dishes and cups, it circulates through the remainder of the tank and is turned downwardly at the front of the tank, as indicated by the arrow 98 in FIGURE 3, to pass outwardly through an opening 10$) in the base of the door 76 and down into a condensing chamber 102. The essentially moisture-free air leaves the condensing chamber through a slot 104 at the base of the condensing chamber and is discharged into the room.

The aforedescribed air circulation path is achieved by a source of air supplied by a pressure fan 106 mounted in the base of the cabinet 10. The fan directs a supply of air up through a conduit 108 'which leads to a Y 110 that splits into two branches 112 and 114, which lead to the inlet openings 88 and 90 to direct air into the interior of the cabinet. The conduit 108 is supplied with heater ele' ments 116 within the conduit to heat the air that passes upwardly into the dishwashing tank 12. To achieve the circulation of air prescribed by the present invention, the air must be dispersed and distributed along the floor 52 of the tank before moving upwardly in the center of the tank. To achieve this, deflector plates 118 and 120 are positioned in the rear corners of the tank and extend outwardly in the general direction of the tank floor 52 to deflect the air in a sheet along the floor 52 of the tank.

Positioned in the path of the air as it moves along the floor of the tank, is a specially located heater element 122. The heater element 122 is shown in FIGURES 2, 3 and 6, but is omitted from FIGURE 1 to more clearly show the spray arms 20 and 22. The heater element has a central U-shaped portion 124 doubling across the floor of the tank beneath the central portion, so as to be located beneath the portion of the rack that supports the hollow cups and glasses 18. The U-shaped central portion 124 of the heater element connects at its ends to two leg portions 126 and 128, which extend across the front of the tank floor 52. The heater 122 may be operated by the same time cycling device that controls the operation of the entire dishwasher and may be placed in operation after the water is drained from the dishwasher tank, and the blower 106 and the heater 116 are started, so that its sole function is to heat the air circulating through the tank. The heater 122, however, may, in many instances, be used as an auxiliary hot water heater being turned on for the entire washing and drying operation of the dishes and thereby serves a dual function. The air entering the drier is, therefore, first heated by the heating element 116 and is subsequently increased in temperature by the heating element 122 within the tank. This heating element is of the immersion type which is not affected by the water within the tank, and is supported from the tank floor, such as by a bracket 123.

The condenser chamber 102 is utilized for removing the moisture from the saturated air as it leaves the tank and before it is discharged into the room. The chamber is provided with a slot 100 extending across its top end and located beneath the door 76. Moisture is kept out of the chamber during normal operation of the drier by a baffle plate 132 extending upwardly in front of the slot 130. A downwardly extending flange or lip 13-4 is carried by the door 76 to project against a curved shield 133 which extends over the baflle plate 132 in spaced relationship to define a gap or slot 130 between them. This arrangement prevents any moisture or water that is being sprayed within the dishwasher during the washing operation from entering the condensing chamber or from escaping under the door. The dishwasher door also may be provided with a seal or gasket under the flange 134 which will prevent escape of moisture.

The condensing chamber is secured to the front of the cabinet and is formed of a pair of vertically spaced plates 138 and 140 with the front exposed plate 138 having an enameled finish to have the same appearance as the cabinet 10. To the plate, as is shown in FIGURES 3 and 4, is connected a series of labyrinth baflles, as illustrated by baffles 142, which are connected to the rear plate 140 and by baffles 144 which are connected to the front plate 138. Each of the baffles, as is illustrated in FIGURE 3, are inclined downwardly so that moisture condensing on their surfaces will tend to drip downwardly, from baffle to baflle, to eventually end up in the liquid tray 146 at the base of the condenser chamber 102. In

addition to being inclined downwardly away from the supporting walls,,each of the baffles is also inclined downwardly along the wall, as shown in FIGURE 4, so that the moisture can run downwardly in both directions dripping off the ends as Well as the lateral side edges of the baflle. These bafiles form a tortuous path with much exposed metal surface for condensing the moisture from the air. The baffles and the walls 138 and of the chamber are cooled by the surrounding air in the room and Within the cabinet. Thus, by the time the air has traversed its path through the condenser chamber 102 and is discharged out through the slot 104, most of the moisture has been condensed and has dripped down into the tray 146. Air is thus discharged into the room without creating a situation of intense humidity.

FIGURE 5 illustrates an alternative type of condenser to be used in the dishwasher combination. In this embodiment, the door 148 is modified so as to contain the moisture condenser. The door possesses an elongated slot 150 extending horizontally for purposes of discharging the moist air from within the tank. As the moist air leaves the tank out through the slot 150 in the door it must pass over a cold condensing plate 154 in the base of the slot. The back or under surface of this cold condensing plate forms the target for a spray head 156 which sprays a stream or a spray of cold water against the undersurface of the plate to maintain it in a cold condition so that it will continue to condense the moisture from the air leaving the tank. The spray head 156 is supplied with cold water from a pipe 153 connected to a flexible tube 160 in the base of the door which permits the door to be pivoted about its base between open and closed position. The flexible coupling tube 160 connects to another pipe leading to the cold water supply of the household which is connected to the dishwasher. The flow of water up to the spray head is controlled by a valve 172 in the pipe 170. The condensed moisture from the air stream and the water from the spray drain into a common drain pipe 174 from an elongated collector trough 176. A baffle 178 in front of the collector prevents the moist air leaving the drier tank from passing directly into the drain pipe 174. The drain pipe leads downwardly through an opening 180 in the base of the door which drains directly onto the floor 52 of the tank and thus the water will run down the inclined floor of the tank to the sump 50. The drain pump 64 may be operated at intervals or at the end of the drying operation to pump the water out of the sump and into the drain line 74.

In the arrangement shown in FIGURES 6 through 9, the structure for forming the dishwashing function may he the same as the embodiment shown in FIGURES 1 through 4. That is, a cabinet 10 may be provided with a closed tank 12 housed in the cabinet and containing the dishes to define a treatment zone within. The front of the tank is open for the removal and replacement of dishes and a door 76 may be hingedly swung between open and closed to close the front of the tank. The dishes 16 are positioned within the tank and for drying, air enters at some point in the tank, preferably through the openings 88 and 89 at the rear corners of the tank, to be deflected forwardly by the shields 118 and 120 to flow across the base of the tank in order that it may circulate upwardly between the dishes 16. Heat may be added to the circulating air by the submersible heating element 122 in the floor 52 of the tank.

The systems shown in FIGURES 6 through 9, however, utilize a different and unique arrangement for conducting the air for the drying operation and for discharging the air into the room. These systems recognize the disadvantages of discharging steam, or air of a high relative humidity directly into the room because of the damage it can do to the furniture and household effects in the room and because of the adverse psychological effect it has on the housewife to see steam billowing into the room. To

reduce the possibility of a visible discharge of steam into the room, an amount of dry air is mixed with the air being discharged into the room from the dishwasher. This will, of course, reduce the proportionate amount of humidity in the total amount of discharged air and can completely avoid discharging visible steam or fog into the room. The dry mixing air may be introduced into the steam laden air at various points in the system and in various proportions in accordance with the arrangement now to be described.

Pressurized air is supplied, for both the drying air and the mixing air, by a centrifugal type fan 190 appropriately housed within the cabinet 10 of the washer. The fan forces a stream of air upwardly through its tangential discharge 192 whereupon the air enters a Y to pass out the branch 194 for the mixing air, or the branch 196 for the drying air. The air which passes outwardly through the branch 196 functions the same as the air discharge with the arrangement shown in FIGURES 1 through 4. The branch 196 may be provided with an additional Y, not shown, which will split the air stream and direct it to the two rear-most corners of the dishwasher tank 12.

In passing upwardly toward the tank, the air is filtered through a heating element 198 so that heated air enters the tank through the opening 88, as is shown in FIGURE 6. This heated drying air is directed along the base of the tank by the deflector 118 and it passes over the submersible heating element 122 to gain more heat and thence rises through the dishware 16 to circulate through the tank. The continuing ingress of air will force the air out through the slot 29%), extending across the front of the tank at the. base of the door 76. This air will, of course, have approached a condition of 100% relative humidity, having evaporated the moisture from the surface of the dishes.

At the slot or gap 200 in the front of the dishwasher tank, the flow of air is distributed with a portion passing down into the condenser 202 and another portion being discharged directly into the room through the space 264 beneath the door. This division of air reduces the amount which must be handled by the condenser 202 since only a portion of the discharge passes through the condenser. This enhances the operating efliciency of the condenser and insures that it will remove a greater amount of moisture from the air which it'treats.

The air which is directed into the condenser is conducted thereto by tubes 206, which have entrance openings 208 positioned in the slot or gap 260 at the base of the door. The tubes lead directly to the upper end of the condenser and force the air into the condenser through their discharge openings 210. The air which does not enter the condenser via the tubes 206, is that which bypasses the tube openings 203 and proceeds directly out through the gap or slot 264, beneath the door to be discharged into the room. In practice, a plurality of tubes 296 may be arranged across the front of the door and the proportion of total air directed into the condenser can be controlled by varying the number of tubes 206 and their cross-sectional area. If the total area of tubes is increased, a greater proportion of air will be directed into the condenser and conversely, if the total area is reduced a smaller portion of air will pass into the condenser. The size of the slot 234 can also be controlled to'reduce the amount of air passing out directly into the room. The tubes may be separated to provide slots 295 between them for the air which passes into the room, and it will be recognized that various air dividing arrangements may be adopted for the division of air between the condenser and the room discharge.

The air which passes out through slot 204 into the room will, of course, have the full amount of moisture that it has gathered in circulating through the interior of the dishwashing tank 12. Upon striking the cooler air of the room, this air will cause a cloud of steam or fog to-bc present unless itis further treated. To avoid this steam effect, a diffusion of dry air is mixed with the steamladen air before it passes into the room, thereby reducing its relative humidity and avoiding the visual appearance of a cloud of steam issuing from the front of the dishwasher. The dry air is introduced to the steam-laden air by a series of nozzles 212 projecting upwardly from a manifold 214 extending across the front of the dishwasher, particularly as shown in FIGURES 6 and 7. The amount of dry air mixed with the steam laden air can be controlled by the size of the nozzle openings 212 and by the pressure of the air being fed to the manifold 214 through the conduit 215.

The dry air is supplied to the conduit 215 from the fan 196 through the branch 194 of the Y which leads from the fan. The division of air from the fan, between the branch 196 leading up to the dishwasher chamber and the branch 194 leading to the manifold for mixing air, is controlled by a deflector vane 2E6. The deflector vane is pivotally supported at 218 and moves between a solid line position and a dotted line position, as is shown in FIGURE 6. When the deflector 216 is in the solid line position, the fan discharge will be split substantially evenly between the branch 124 and 196, and when the deflector moves toward the dotted line position a decreased amount of air will be discharged to the branch 194. The air passing up through branch 194 and through the conduit 215 will, of course, be dry room air and when mixed with the air issuing from the slot 204, will reduce the percentage of moisture content to avoid steam, and the moisture thus distributed will be less likely to condense on any cool surfaces in the path of air.

The moist air which passes downwardly through the condenser 262 loses its moisture on the surfaces of the baffles 220 and the walls 222 and 224 of the condenser. After the moisture has been removed from the air, the air is discharged through the openings 226 at the base of the condenser. These openings are raised slightly above the base so that a pan 228 will be formed in the bottom of the condenser for receiving the condensed moisture droplets that run down the walls 222 and 224 of the condenser.

Since the condenser will have to handle only a reduced amountv of the air passing through the dishwasher, it will easily remove the entire moisture therefrom and theair being discharged through the openings 226 will be dry and will not be in the form of steam to condense on household surfaces or to alarm the housewife.

It is further contemplated that dry air from the conduit 215 may be introduced directly at the slot 204 to mix with and diffuse the moisture, laden air without using the condenser 202.

The greatest amount of moisture will be picked up by the air during the beginning of the drying operation, since at this time the greatest amount of moisture is available from the dishes and also because there is a larger amount of residual heat in the moisture and dishes to cause a faster evaporation. Therefore, it is desirable that a greater amount of dry air be mixed with the air being discharged through the slot 264 at the beginning of the drying operation. For this purpose, the deflector 216 may be varied in position during the drying procedure.

As is illustrated in FIGURE 9, the damper 216, which is pivotally mounted between the branches 194 and 196 at 218, is positioned at the solid line position at the beginning of the drying operation to discharge the greatest amount of air into branch 194. After the initial drying period and after the moisture is evaporating from the dishes at a reduced rate, the deflector 216 is shifted to the dotted line position in order that less drying air be operating arm 243 secured to, the deflector blade, suchv as by being connected to a pivotal shaft that may be connected to the blade at its pivotal axis 218. A tension spring 236 suitably attached to a bracket 238 within the drier cabinet pulls the blade 216 to the solid line position. The arm 24-8 is also connected to a link 240 which is secured to the plunger 242 of a solenoid 244. The leads 246 of this solenoid connect to an electrical system through a switch which may be controlled by the time cycle switch that automatically operates the machine. The solenoid 244 thus will be energized after an initial drying period to pull the blade 216 to the dotted line position, and the amount of drying air passing up through the conduit 215 will automatically be reduced when less air is needed to avoid steam from being discharged into the room.

Since the amount of moisture evaporated into the drying air is gradually reduced during the drying operation, it may, in some cases, be desirable to gradually reduce the drying air mixed with the moist air discharged from the dishwasher. This may be effected by a control which gradually moves the deflector 216 from the solid to the dotted line position. In the embodiment illustrated in FIGURE 6, the arm 248 connected to the deflector is secured to a link 250 leading to a lever arm 252. The lever arm is pivotal-1y supported on a bracket 254 and the upper end of the lever arm connects to a temperature responsive element 256, which is shown mounted in the wall of the condenser, but which may be positioned at any point to be responsive to the drying air coming from the dishwasher. Since the amount of moisture picked up by the drying air is reduced in proportion to the reduction of residual heat in the dishes, and thus the temperature of the drying air drops in proportion to its moisture content, the temperature responsive element 256 can be used to mechanically alter the position of the deflector 216 and automatically gradually reduce the amount of dry air mixed with the moist air being discharged from the dishwasher as the moisture content of the air drops with its temperature. If desired, the element 256 may be changed to a humidity responsive element so that the dry air mixed with moist air may be in the exact proportion to the humidity content of the air leaving the drier.

Instead of mixing the dry air with only a portion of the moist air, the airangement of FIGURE 8 mixes dry air with the total amount of moist air, but some of the moisture is removed from all of the moist air by the condenser.

To accomplish this, the dry air conduit 215a communicates with the base of the condenser 202a so that the dry air mingles with the air being discharged from the condenser as it passes out through the opening 226a. Althrough the air which is passed downwardly through the condenser may not have lost its entire moisture, by being mixed with dry air, its relative humidity is reduced sufficiently to avoid discharging visible steam into the air. In this instance, a conduit 260 will receive all of the air leaving the dishwasher, and will direct all of the moisture laden air into the condenser 202a.

Although the operation of the invention is believed clear from the foregoing descn'ption of the integrated elements of the machine, a brief summary of operation of the overall machine will be helpful in understanding the objects, features and advantages of the invention. With reference to FIGURE 3, the operator first loads the tray 14 with dishes having pulled the tray from the interior of the tank and having pivoted the door 76 to the open position. As is shown in FIGURES 1 and 2, the tray 14 is so designed so that the cups and glasses 18 may be best stacked in the center of the tray, and the flat dishes 16 stacked in the slots at the sides of the tray. The rack 14- is then pushed back to the position shown in FIGURE 1 within the tank 12, and the door 76 pivoted to closed position. The dishes are then washed by the sequential operation of the rotating spray arms 20 and 22 and the rotating spray tube 43 positioned in the top of the tank. Circulation of the water through the spray arms and the spray tubes is effected by the pump 44, and at the end of the washing operation the pump 44 is stopped and the drain pump 64 is operated to remove the water from the sump 50 where it is drained from the inclined floor 52 of the tank.

In the embodiment shown in FIGURES 1 through 4, the heated drying air is next forcibly circulated through the tank 12 by operation of the fan 106 forcing air through the conduit 1% wherein it is heated by the heating element 116, as is shown in FIGURES 2 and 3. The air divides at the Y 108 and enters the tank through the openings 88 and 91 to be deflected across the floor 52 of the tank by the deflector plates 113 and 120. Where the streams of air 92 and 24 meet at the center, after being additionally heated by the heating element 122, they are diverted upwardly to pass into the interior of the inverted cups and glasses 18 to insure evaporating the moisture from the surface thereof. The air then circulates and diffuses through the dishes in the rest of the tank, the dishes themselves being heated by the radiant heat of the immersion heating element 122, and leaves the tank passing through the slot 130, FIGURE 3, into the condenser 1&2. The air passing downwardly flows through the tortuous path defined by the baffles 142 and 144 and passes outwardly through the slot 104. The condensed moisture collects on the walls 138 and 140 and on the batlles cooled by the ambient air, and drips downwardly off the baflles to collect in the tray 146. The water can be removed by drainage, or if left in the bafiles it will evaporate slowly over a period of time when the dishwasher is not in operation. This slow evaporation between usages of the dishwasher will consume a period of a number of hours, for example between meals. This distributes the moisture into the air slowly and does not create an intense amount of moisture at one time, but merely increases the humidity slightly over a long period of time and thus performs a beneficial rather than an undesirable effect.

With the embodiment shown in FIGURES 6 through 9, the dishwashing operation is identical with that described in connection with the embodiment of FIGURES 1 through 4. The drying operation within the dish treatment zone is also identical, except that a portion of the drying air is channeled to the front of the dishwasher to be mixed with the moist air. As is illustrated in FIGURE 6, the moist air leaves the dishwasher through the slot 200 and divides, with a portion of the air being discharged through the slot 2G4 directly into the room and the remainder entering the tube 2W5 to be directed into the condenser 262. The portion that passes downwardly through the condenser is relieved of its moisture and the droplets gather in the tray 228, and the air is disc iarged through the openings 226. The other portion of moist air is mixed with diffused dry air issuing from nozzles 212 and the dry air is supplied through the conduit 215 from the fan 1%.

In the arrangement of FIGURE 8, the dry air is mixed with the moist air after a portion of the moisture has been removed by the condenser 292a. All of the moist air is directed through the condenser and if an excess amount of moisture still remains in the air, the relative humidity of the air will be sufliciently reduced by mixing with dry air from conduit 215a to be permitted to be discharged into the room through the opening 226a.

The amount of dry air required to maintain the relative humidity of air issuing into the room below the point where steam will be visible is reduced as the moisture content of the air leaving the dishwasher is reduced. This moisture content decreases considerably after an initial drying period. The amount of dry air mixed with the moisture laden air is controlled by a deflector 216, FIGURE 9, and this deflector may be moved from a solid line position to a dotted line position by energization of the solenoid 244 to thereby decrease the amount of mixing air after the initial drying period. In the arrangement of FIGURE 6, the volume of drying air is gradually reduced in proportion to the temperature of the air leaving the dishwasher, and the temperature of the air is an indicia of the amount of moisture it contains. This control is obtained through a temperature responsive element 256 in the form of a gas filled wafer or a bi-metal element which mechanically pivots a lever arm 252 to pivot the deflector 216 through the link 2511 and control arm 248.

Thus, it will be seen that we have provided an improved drying system for an automatic domestic dishwasher which meets the objects and advantages hereinberore set forth. The mechanism is simple in construction and does not interfere with the features of operation of the dishwasher. The mechanism avoids the necessity of having to leave the dishwasher open and the dishes exposed to the air of the room and thus improves the cleanliness and sanitation of the dishwasher operation.

The mechanism also avoids discharging large amounts of moisture into the air and insures that the dishes will be completely dried. The dishwasher can remain closed and will not have to be attended until it is opened when the dishes are again needed.

The method and apparatus employing the features of the invention also prevent visible steam from being discharged into the room. The relative humidity is reduced by mixing with dry air and the quantity of dry mixing air can be adjustably controlled.

We have, in the drawings and specification, presented a detailed disclosure of the preferred embodiments of our invention, but it is to be understood that we do not intend to limit the invention to the specific form disclosed, but intend to cover all modifications, changes and alternative constructions and methods falling within the scope of the principles taught by our invention.

We claim as our invention:

1. A dishwasher or the like, comprising an enclosure having spaced top and bottom walls, front and rear walls and opposed side walls cooperatively defining a dish treatment zone, a pair of conduit members protruding upwardly through said bottom wall in the two rear corners of said enclosure provided by said rear wall and opposed side walls, a deflector mounted closely above each conduit member and shaped to direct a moving air stream along said bottom wall from said two rear corners and toward the center of said bottom wall for intersection with the air stream from the other conduit member, and fan means connected to said conduit members and forcing air upwardly therein and against said deflectors for movement along said bottom wall of said enclosure, the air streams from said conduit members then intersecting at generally the center of said bottom wall and moving upwardly therefrom toward said front wall of said enclosure for discharge from said treatment zone along the front lower portion thereof.

2. A dishwasher or the like, comprising an enclosure having spaced top and bottom walls, front and rear walls and opposed side walls cooperatively defining a dish treatment zone, a pair of conduit members protruding upwardly through said bottom wall in the two rear corners of said enclosure provided by said rear wall and opposed side Walls, a connector member connecting said conduit members below said bottom wall, heating means in said connector member applying thermal energy to the air stream moving therethrough, a heater in said treatment zone disposed in closely spaced relation to said bottom wall for heating the dishes in said treatment zone, a deflector mounted closely above each conduit member and shaped to direct a moving air stream along said bottom wall from said two rear corners and toward the center of said bottom wall for intersection with the air stream from the other conduit member, and fan means connected to said conduit members and forcing heated air upwardly therein and against said deflectors for movement along said bottom wall of said enclosure, the air streams from said conduit members then intersecting at generally the center of said bottom wall and moving upwardly therefrom toward said front wall of said enclosure for discharge from said treatment zone along the front lower portion thereof.

3. A dishwasher or the like, comprising an enclosure having spaced top and bottom walls, front and rear walls and opposed side walls cooperatively defining a dish treatment zone, said front wall having an air discharge opening adjacent its connection to said bottom wall, condenser means communicating With said air discharge opening, a pair of conduit members protruding upwardly through said bottom wall in the two rear corners of said enclosure provided by said rear wall and opposed side walls, a deflector mounted closely above each conduit member and shaped to direct a moving air stream along said bottom wall from said two rear corners and toward the center of said bottom wall for intersection with the air stream from the other conduit member, and fan means connectedto said conduit members and forcing air upwardly therein and against said deflectors for movement along said bottom wall of said enclosure, the air streams from said conduit members then intersecting at generally the center of said bottom wall and moving upwardly therefrom toward said front wall of said enclosure for discharge through said air discharge opening in said front wall and into the communicating condenser means.

References Cited in the file of this patent UNITED STATES PATENTS 1,452,066 Cave Apr. 17, 1923 1,900,846 Russell et a1 Mar. 7, 1933 1,981,234 Hetzer NOV. 20, 1934 2,064,084 Sando Dec. 15, 1936 2,318,511 McAllister May 4, 1943 2,390,757 Voris Dec. 11, 1945 2,487,722 Nuvell Nov. 8, 1949 2,627,669 Candor Feb. 10, 1953 2,674,249 Knight Apr. 6, 1954 2,691,986 Kirby Oct. 19, 1954 2,737,799 Knipmeyer Mar. 13, 1956 2,785,557 Stilwcll Mar. 19, 1957 2,797,567 Heien July 2, 1957 2,858,688 Smith Nov. 4, 1958 2,859,755 Burke Nov. 11, 1958 2,957,330 Cline Oct. 25, 1960 FOREIGN PATENTS 89,088 Germany Oct. 29, 1896 598,764 France Oct. 5, 1925 983,433 France Feb. 14, 1951

Images