US3064664A

US3064664A - Dishwashing machine

Info

Publication number: US3064664A
Authority: US
Inventors: John D Warhus
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1957-09-20
Filing date: 1957-09-20
Publication date: 1962-11-20
Anticipated expiration: 1979-11-20

Description

Nov. 20, 1962 J. DJWARHUS I DISHWASHING MACHINE Filed Sept. 20. 1957 H ll' a Sheets-Sheet 1 INVENTOR. JOH N D. WARHUS lam/4M ATTORNEY Nov. 20, 1962 Filed Sept. 20, 1957 J. D. WARHUS DISHWASHING MACHINE 6 Sheets-Sheet 2 INVENTOR. JOHN D. WARHUS MA JAMAQ/ ATTORN EY Nov. 20, 1962 J. D. wARHu's 3,064,654

DISHWASHING MACHINE Filed Sept. 20, 1957 6 Sheets-Sheet 3 INVENTOR. JOHN D. WARHUS ATTORNEY Nov. 20, 1962 J. D. WARHUS ,664

DISHWASHING MACHINE Filed Sept. 20, 1957 e Sheets-Sheet 4 i i 51 x} 8 K 4 I 42 42 Z; m u 20 43 20 I A 2 I I mm INVENTOR. m I 39 JOHN D. WARHUS BY q 39 Wk M I 3 ATTORNEY Nov. 20, 1962 J. D. WARHUS DISHWASHING MACHINE Filed Sept. 20, 1957 6 Sheets-Sheet 5 JOHN D. WARHUS Q iMA/W ATTORNEY Patented Nov. 29, 3852 lid 3.064.664 DIHWAHING MACHINE John D. Warhus, Lombard, 11]., assignor to General Electric Company. a corporation of New York Filed Sent. 20, 1957. Ser. No. 685,303 7 Claims. (Cl. 134-176) This invention relates to domestic appliances, such as dishwashing machines.

The modern automatic dishwasher'used domestically, as distinguished from the specialized apparatus used in restaurants and other large-scale eating establishments, is subject to being rather haphazardly loaded by the user, and because the washing of the dishes within the dishwasher tub is effected by the impingement of multitudes of droplets of washing liquid against the dishes. it will be seen that the loading arrangement of the dishes has much to do with the effectiveness of the washing action. It will also be obvious that because the manner in which the dishwasher is loaded and used may vary from day to day, or even from meal to meal, the washing etl'lciency may vary over a rather wide range;

The majority of domestic dishwashers presently use either an impeller or a reaction spray device in the lower 13ft of thetub-and thus depend on upwardly directed water sprays to wash the miscellany of dishes and other articles placed in open-work racl sor a spray device disposed intermediate the upper and lower racks and designed to obtain a suitable water distribution pattern.

The disadvantage of the first-named arrangement is that its efiectiveness is particularly subject to the manner of loading and type of dishes; whereas in dishwashers embodying the second circulation arrangement, bowls, cups, and glasses must be arranged in inverted fashion in the upper rack. This, it is not always possible'to do.

It has previously been proposed to employ a reaction spray device below the lower rack, and a second one intermediate the upper and lower racks. This arrangement is productive or a good water distribution pattern, but the necessary pipe connections have been costly and bulky, and the intermediate reaction spray device has on occasion damaged dishes by striking them during rotation. The reaction spray devices of the prior art have usually comprise a twoor three-armed device mounted for free rotation in a horizontal plane, and havingvariously disposed nozzles effective when liquid under pressure is supplied thereto, to rotate the device and provide a wide coverage and e;re..tive contact of the washing and rinsing liquids with tie dishes and other articles placed in the rack immediately thereabove.

It is an object of the present invention to provide a dishwasher using upper and lower spray nozzle devices, arranged to produce optimum washing action without possibility of damage to the dishes within the tub.

It is another object of the invention to provide an upper spray nozzle device which is fixed relative to one of the racks for an efficient spray pattern relative to the dishes in the washing chamber or tub, and automatically becomes physically detached from its liquid supply means when said supply means is shut oil, thereby permitting said rack to be reely moved relative to the tub to facilitate loading or unloading the rack.

It is a further object of the invention to provide a novel means for automatically coupling and uncoupling the upper and lower spray nozzle devices of a dishwasher.

It is still another object of the invention to provide improved means for rotatably mounting'a spray nozzle device in proper position within a dishwasher tub.

' In a presently preferred embodiment of the invention, a dishwasher tub is provided with a bottom hinged door, movable between a substantially vertical closed position and a substantially horizontal open position. An upper and a lower dish-receiving rack are supported within said tub in a manner permitting them to be with; drawn through the door opening to facilitate leading, us is well known in the art. A liquid distribution such as a reaction-type spray nozzle device is rot-stably mounted beneath the lower rack for rotation in a horizontal plane, and motor-driven pump means is provided for drawing the washing liquid from a low point within the tub and discharging it at relatively high pres sure into the liquid distributor, from the radially extending arms of which it issues in variously disposed sprays and jets reflective to impinge against the articles in the racks immediately above and thus wash them. Certain of the jets are arranged to produce a rotation of the distributor as long as the liquid is supplied thereto at necessary pressure.

The lower rack rotatably supports a vertical, rigid water supply conduit having a bell-ed, open end, disposed, when the rack is in operative position, immediately above an upwardly facing discharge port in the hub portion of the liquid distributor. Said conduit terminates intermediate the upper and lower rack, and at its upper end carries a second spray nozzle liquid distribution device having discharge ports which direct streams of liquid in various patterns against the articles located in the upper and lower racks. Said second distributor may or may not have reaction jets to impart a rotative efiort thereto, because pursuant to a preferred form or" the invention rotative effort is applied thereto by the lower distributor. to the lower rack engage with a fitting at the top of the upper liquid distributor.

An important aspect of the invention is that means are provided for automatically coupling the conduit to the lower liquid distributor when the lower rack is in operative position and liquid under pressure is delivered to said lower distributor. By means of this coupling, liquid under substantial pressure is supplied to the conduit and thence to the upper distributor when the dishwasher is in any of its water-using cycles, such as the washing or rinsing cycles. At the end of such cycles, the conduit is automatically uncoupled from the lower liquid distributor, making it possible to withdraw and return the lower rack without conflict with the lower distributor. In a presently preferred embodiment, I utilize an annular expansion coupling fixed about the axial discharge opening provided by the open upper end of the hub portion of the lower liquid distributor. Said coupling has an inwardly extending flexible lip which defines a discharge port of substantially less area than the said axial opening in the distributor. When the lower rack is in home position, the 'belled end of the conduit is disposed immediately above but in spaced relation to the discharge port of the coupling. When liquid under pressure enters the coupling from the lower liquid distributor, the pressure exerted against the underside of the lip causes the coupling to move upwardly into sealing relation with the conduit and liquid under substantial pressure is thereby delivered 'by the conduit to the upper water distributor. So positive is the engagement of the lip of the coupling with the conduit that the conduit and its associated upper distributor is actually lifted relative to the lower rack, and is rotatively driven by the lower distributor.

Another feature of the invention resides in the fact that the upper liquid distributor comprises a flat disklike structure of plastic material. The rounded peripheral edge of the upper distributor and the inherently resilient nature of the material substantially eliminates the possibility of damage to articles which Bearing means suitably supported relative through careless loading of the racks may rest against or be struck by the rotating disk.

Although the dishwasher embodying the present invention may be arranged for gravity drainage, I prefer to use a drain pump to insure fast and complete removal of the dishwasher liquids. The drain pump inlet is dis posed substantially centrally of the screen, and thus is in a position efficiently to accumulate and discharge the food soil which has gathered in the sump.

Other features and advantages of the invention will be apparent from the following description of a presently preferred embodiment, read in connection with the accompanying drawings in which:

, FIG. 1 is a side sectional elevation of a dishwashing machine, taken on lines I i of FIG. 3, with the filter structure removed, the loading door partly open, and the lower rack partially projecting through the opening;

FIG. 2 is a front sectional elevational view of the dishwasher with the front door removed and the lower front panel partially broken away to disclose structural details and accessories normally concealed thereby;

FIG. 3 is a plan section of the dishwasher tub looking in the direction of the arrows 33 of FIG. 2, but with the filter structure removed;

FIG. 4 is a fragmentary sectional elevation taken on lines 4-4 of FIG. 3;

FIG. 5 is a sectional elevation taken on lines 55 of FIG. 3 showing the relationship of the filter screen to the drain pump inlet;

FIG. 6 is a fragmentary sectional elevation of the hub portion of the lower liquid distributor and the lower portion of the upper distributor conduit, with the flexible coupling in relaxed condition;

FIG. 7 is a view similar to FIG. 6, showing the flexible coupling in extended condition;

FIG. 8 is a plan view of the upper liquid distributor;

FIG. 9 is an upper sectional elevation of the upper distributor and conduit; and

FIG. 10 comprises a schematic wiring diagram and cam sequence chart. I Referring initially to FIG. 1, the dishwasher 1 embodying the present invention comprises a washing chamber or tub 2 suitably housed within a structural casing 3. The tub has a front opening fitted with a bottom hinged door 4 which is shown in a partially open position. The door is arranged to operate between a substantially vertical closed position and a substantially horizontal open position. The door, or the tub margin, as desired, is ordinarily fitted with a suitable gasket (not shown) for sealing the tub when the door is in its closed position. The side walls of the tub are provided with a pair of upper tracks 5 and a pair of lower tracks 6 which respectively support the upper dish rack structure 7 and the lower dish rack structure 8. For example, the respective racks are suitably provided with rollers which engage with the tracks, to permit the upper and lower racks to be withdrawn through the front opening of the tub to facilitate loading the racks with the dishes and other articles (not shown) to be washed. Preferably, means is provided to prevent the complete withdrawal of the upper rack 7. The lower rack 8 substantially completely occupies the lower portion of the tub when it is in operative position, but may be withdrawn completely from the tub, in view of the fact that in such a circumstance it will be supported by the horizontal inner panel of the door 4 when the later is in its fullopen position. The upper and lower racks are of openwork construction and include various formed-wire supporting structures, pursuant to which cups, glasses, saucers, and other small articles may be suitably arranged in the upper rack, and dishes, platters, bowls, and the like may be placed in the lower rack. A silverware basket (not shown) is normally removably associated with the lower rack for articles of tableware.

The bottom of the tub 2 slopes to a sump portion,

which, as shown in FIG. 2, is somewhat to the right of the tub when viewed from the front. A solenoid-operated valve 9 connected by way of a pipe 10 to a source of heated water (not shown) is provided for supplying the tub with heated water. The valve discharge tube 11 extends vertically between the tub and the outer casing 3, and the water issuing therefrom passes through a vertical air gap of not less than one inch into a pipe 12 which communicates with the interior of the tub. A pressure switch 14- (FIGS. 1 and 3) having a diaphragm 15 exposed within the tub is responsive to the head of water within the tub; and if because of some faulty operation of the machine a quantity of water accumulates within the tub, the switch 14 will operate to open the valve circuit, thus preventing overfilling. The dishwasher apparatus is arranged to be fully automatic in its operation and a conventional time-cycle controller 16 is suitably disposed within the dishwasher door. The timecycle switch is provided with a control knob 17 on the outside of the door, and, as will more fully appear hereinafter, the time-cycle switch will conduct the dishwasher operation through a predetermined cycle of washing and rinsing operations. The inside panel of the door carries a device for the introduction of detergent into the water so as to produce a suitable washing liquid. The detergent introduction device 18 is desirably of the type in which fresh detergent is mixed with water in each of two washing operations, as shown and described inv the Sharp et al. Re. 24,198, entitled Dishwashing Apparatus with Automatic Detergent-Dispensing Means, and assigned to my present assignee. A heating unit 19 of the tubular sheathed resistnce type is mounted within the tub to facilitate the drying operation. In the present embodiment of the dishwasher, two gallons of water are used in each of the washing and rinsing operations, but this relativelysmall quantity is circulated at the rate of thirty gallons per minute. At no time, therefore, is there any substantial depth of liquid within the tub. For the washing operations, the water mixes with detergent to provide the washing liquid. Rinsing is carried out by clean hot water, although in the final rinse a water conditioner, such as a wetting agent, may be added.

The washing and rinsing of the articles contained in the respective racks 7 and 8 is accomplished by means of sprays of liquid forcefully ejected from a pair of rotating spray devices which efficiently distribute the liquid throughout the tub. The lower liquid distributor comprises a reaction spray device rotatably mounted below the lower rack 8, whereas the upper distributor comprises a different form of spray nozzle device which is rotatably mounted between the upper and the lower racks. The lower distributor 29 is illustrated as a twoarmed device provided with a plurality of upwardly facing slots 21 which spray the washing or rinsing liquid against the articles in the lower rack, and with opposingly directed openings 22 which provide reaction forces which cause the lower distributor to rotate. This action literally drenches the dishes and other articles which are racked in the lower portion of the tub. The upper water distributor 23 comprises a relatively flat, hollow disk-like structure which is advantageously molded of thermosetting plastic, such as Bakelite. The rounded periphery of the upper distributor and the complete absence of any sharp edges or projections makes it impossible to damage dishes which may accidentally come into contact with it. The upper distributor is provided with

suitable ports

24, 25, 26, 27, and 28, later described in detail, which produce water streams which extend in a generally outward and upward direction.

During the washing and rinsing operations, the upper and lower distributors are continuously supplied with liquid at a pressure which at admission to the lower distributor is about eleven pounds per square inch gage. This is provided by a centrifugal pump 3% disposed in a. com

par cent below the tub, and driven by an electric motor 31. The pump inlet 32 communicates with a tube 33 formed in the combined water circulation and drain fitting 34, best shown in PEG. 4. The inlet to said tube 33 comprises a cylindrical collar or baffle 35 which projects upwardly into the tub for about one-half inch and receives a portion of the filter structure 36, as presently described.

The pump outlet 37 communicates directly with a support and supply conduit 38 for the lower distributor. Advantageously, the connection between the pump outlet 37 and the conduit 38 comprises a combination gasket and sleeve 39, best shown in FIG. 6. The pump outlet 37 fits within the sleeve 39 which, as shown in FIG. 6, has an outwardly extending flange 39a, which receives the bottom of the tub 2 and supports the flanged base 38a of the conduit 33. Any suitable means, such as the illustrated fastening devices, may be used to maintain the respective parts in a suitable water-tight relationship.

The conduit 38 is provided with an interior spider 40 which carries an elongated pivot bearing 41 arranged'coaxially with the conduit 38. Bearing 41 rotatably receives a socket 42 which is preferably an integral part of the hub 43 of the lower distributor 20. A tubular extension 47 of said hub is outwardly flared to receive the base 44 of the flexible coupling member 45. it will be observed from FIG. 6 that the axial opening 46 in said coupling member is considerably smaller than the axial opening 47 of the hub i3, whereupon when liquid is flowing through said extension under pressure from the pump 3%, the coupling will be displaced in an axial direction. Preferably, the flexible coupling is of a synthetic rubber-like material, such as neoprene, which is resistant to the detergents used in present-day dishwashers. In a present embodiment of the invention, the pump pressure within the hub 43 of the lower distributor 20 is of the order of eleven pounds per square inch, and said pressure is distributed over about three square inches of the end of the coupling 45, whereupon there is an effective force of about thirty-three pounds applied against the inside of the coupling to upwardly expand the same.

As more specifically disclosed in the presently pending application of Thomas P. Zurek, Serial Number 685,447, filed September 23, 1957, for dishwashing apparatus and assigned to my assignee herein, it has been found possible to eliminate rotating seals and the like at the juncture between the conduit 38' and the hub 43 by beveling' the lower edge of said hub so that the wall of the hub ext ads into a very close, but nevertheless finite clearance, forms a very sharp angle with the inside wall. The hub re ionship with the upper fiat wall of the conduit 38, and it will be noted from FIG. 6 that the inside diameter of the hub 43 is slightly larger than the inside diameter of the conduit, whereupon the knife edge 48 of the hub 43 is intermediate the inner and outer walls of the conduit 33. There is, of course, a very small escape of liquid through the clearance space between the hub and the fitting. Any small food soil particles which may haveescape the screen will not lodge in the clearance space because of the escape facilities provided by the beveled edge It has previously been noted that the upper liquid distributor 23 is supported by the lower rack 8. As shown in FlGS. 1 and 6, the support includes the metal conduit 5% which has about its lower portion a hub 51 which may be of nylon or the like. The lower portion of the nylon hub is beveled, as at 52, to pilot into a ring-like support 53 which is formed in the bottom of the rack 8. It will be noted from P16. 6, that the inner wall of the hub 51 is grooved; the outer wall of the conduit 59. is knurled, as at 54, to provide an interlocking relationship with one of the internal grooves of the hub. The conduit 5i enters the hub 55 of the upper distributor 23 to supply water to said distributor, as later described. Additional support for the upper distributor is provided by the bearing 56 which is disposed at the extremity of the support frame 57 fixed to and extending upwardly from. the lower rack 8.

The lower end of the conduit 50 is provided with a bell-like mouth at which is disposed immediately above the upper flexible end of the expansion coupling 45. The hub 51 maintains a concentric relationship between the conduit 50 and the lower distributor hub 43 when the lower rack 8 is in its operative position. The relationship of the lower rack to the inner panel of the door 4 is such that the rack 8, if slightly out of position as the door is closed, will be engaged by the door panel and moved to its operative position. As appears in FIG. 7, when the machine is in operation and water under pressure is issuing through the hub 43 of the lower distributor, the expansion of the flexible coupling 45 brings it into positive engagement with the lower surface of the bell 60 and actually lifts the upper distributor assembly relative to the lower rack 8. Thehub 51 at'the lower end of the conduit 56 is then in a definite clearance relationship with the portion 53 of the lower rack. This of course reduces the friction of the'upper distributorrotating system, a nd although the upper distributor. may be formed to have reaction jets, it is primarily rotated by means of the firm pressure engagement between the coupling member 45 and the bell 60.

As best shown in FIGS. 8 and 9, the upper liquid distributor 23 is arranged so that in spite of its small diameter as respects the lower distributor, it provides avery efiicient liquid distribution pattern. The outside diameter of the upper distributor 23 is, in the present commercial embodiment of this invention, six inches, as compared with the eighteen inch arm spread of the lower distributor 20. The upper distributor 23 is provided with tWoarrangemerits of marginal slots which are characterizedby different extents of fan-Wise discharge. For example, the slots 24 are arranged (FIG. 8) so that the fan-like discharge therefrom makes an angle of approximately fifty degrees relative to the horizontal, whereas the slots 25 are formed so that the discharge makes an angle of approximately thirty-five degrees from the horizontal. There are, in addition, angularly inclined circular ports 26' which are disposed at substantially the horizontal center line of the distributor. The ports 26 may, if desired; be arranged to produce reaction jets for the rotation of distributor 23.

The top of the distributor is similarly provided with two arrangements of water ejection slots. A central group of slots, identified as 27, projects directly upwardly. It will be noted from MG. 8 that none of this group ofslots is at the same radius from the axis of rotation of the distributor. The second group of slots 2-8 is sufficiently close to the upper marginal edge of the distributor to permit a slight outward incline. The resulting action is essentially to discharge liquid under pressure in an outward direction from the

slots

24, 25, and 26; in a directly upward direction from the slots 27; and in a substantially upward but somewhat outward direction from-the slots 28.

It will be observed from FIG. 9 that the upper distriow tor is a two-part device in which the hub 55 has a portion which is in a keyed relationship to the upper end of the conduit 51} and is fixed thereto by set screws 62 or equivalent. The upper portion of distributor 23 is provided with a central hub 63 which provides means for mounting the upper needle bearing member 64 which upon an extreme upward displacement of the conduit 5%, as aforesaid, may rotatably seat within the conical base of the- These walls are adaptedto enter the collar 35- so as frictionally to engage the inside wall thereof. The engagement of the walls within the collar 35 stabilizes the filter relative to the drain fitting and, together with the short leg portions 71 (of which there are two at the front of the filter and rest upon the bottom wall of the tub 2), securely supports the filter structure relative to the tub bottom. A fixed handle 73 facilitates the insertion and removal of the filter. A boss 74 is arranged to receive the screw 75 which forms the primary means for securing the filter screen 76 in position. As is evident from a comparison of FIGS. 4 and 5, the screen 76 is a generally concave structure, the upper edge of which engages the rim or shoulder 69 within the filter cover 66. The projected area of the screen 76 is substantially less than that of the cover 66.

The drainage fitting 34 has a relatively deep sump '77 which drains toward the outlet 78. A drainage pump conduit 80 issuitably secured about the outlet 78 and communicates directly with the drainage pump 81 which is driven by an electric motor 82. The discharge 33 from the pump 81 rises to a point substantially above the bottom of the tub for discharge-through an air break (not shown) of at least one inchinto the plumbing waste line (not shown) of the building. A coarse guard plate 84 prevents passage of material which might clog the discharge pump.

The element 70 extends through a suitable aperture in the screen, and when the filter structure is in operative position, a portion of the screen immediately circumscribing the aperture rests upon the upper edge of the collar 35. When the pump 3!) begins operation for a wash or rinse portion of the operational cycle, the liquid level in the sump is below the rim 67 of the filter cover 66. The liquid can flow to the pump 30 only by passing upwardly through the filter screen 76 and then through the passages provided by the walls of the element 70 into the pump inlet connection 32. Heavy food soil will accumulate in the sump 77 and will enter the drain pump inlet pipe 80; the lighter soil will be intercepted on the outside of the screen 76 and thus prevented from passing into the water distributor system. Any small particles of soil which may penetrate the screen 76 will be carried into the inlet 32 by flow along the passages provided by the walls of the element 70. The pumping rate of thirty gallons per minute floods the interior of the filter structure, and because the operation of the pump 30 is abruptly terminated at the end of the washing or rinsing operation, the liquid within the filter will backfiow through the screen and remove the food soil therefrom.

An important aspect of the filter design is that when the pump 36 is in operation, there is a slight negative pressure existing Within the filter structure, and the atmospheric pressure within the tub exerted over the relatively larger area of the imperforate cover 66 tends to hold the filter structure firmly against the thrust exerted by the upward flow of liquid through the screen.

FIG. comprises a composite figure showing the cam sequence chart and a schematic wiring diagram for a control system useful with a dishwasher embodying the present invention. The sequence timer 16 includes a synchronous motor 85 which may be of the well-known Telechron type. Said motor operates through a speed reduction and friction clutch mechanism 86 to drive a cam shaft on which are mounted six cams, designated 37 to 92 inclusive. The knob 17 on the cam shaft provides for manual rotation of the cams to place the cams in a home position, advance the operation to any desired cycle, or to shorten a particular operation. The friction clutch permits such manual operation, as is well understood in the art.

Cam 87 controls the operation of the drain pump motor 82; cam 88, the heating element 19; cam 89, the circulation pump motor 31; and cam 90, the solenoid coil of the water valve 9. Cam 9]. is the so-called short cycle cam which comes into operation when the user wishes to operate the dishwasher for an abbreviated cycle, as presently explained, and cam 92.jis a bypass cam which maintains the timer motor in operation at or the line 93 switch has been automatically opened by operation of the timer. With respect to this latter feature, it may be noted that the particular form of timer used by my assignee herein is of a conventional and commercially well-known type in which the cam shaft is manually movable in an out' ward axial direction, and in its outwardly moved position closes the line switch 93; and when the timer has rotated the cam shaft through the major part of its operational cycle, the cam shaft is automatically returned to a home position in which the line switch 93 is opened. A door switch 94 is of a conventional, normally open type; it is operated to closed circuit position when the dishwasher door is closed, and assumes its open position whenever upper edge of the door is moved as little as one-eighth of an inch away from fully closed position. A beneficial effect of such an arrangement is that if the door is open sufficiently to permit the rack 8 to be displaced relative to the lower distributor 26, the dishwasher is inoperative.

Assuming now that the machine has been loaded with dishes and that detergent has been placed in each of the cups of the detergent dispenser 13 and the dispenser placed in its operating position, as is fully described in the said Sharp et al. Reissue Patent 24,198, the user then determines whether the machine is to operate through its normal washing, rinsing, and drying cycle, or whether it is to operate on the abbreviated cycle. According to her decision, she operate the pushbutton switch 95; and assuming that she has decided on the full cycle, her operation of the switch will close the contacts thereof and thereby shunt-out the switch 91a which is associated with the short cycle cam 91. When the door is closed (which closes witch 94), the user pulls outwardly on the control knob 17, thus closing line switch 93 and energizing the electrical system.

The timer motor begins operation immediately. Switch a in the water valve circuit is in closed circuit condition at this stage of operation, and so, of course, is the water switch 14, for there is no water in the tub.

Cam 87 is holding switch 87a closed at this time, and

the drain pump motor 82 is therefore operating. The result is that for the first sixty seconds, water is flowing into the tub through the inlet pipe 12 and is passing directly to the drain pump 82 for discharge. The purpose of this is to purge the valve inlet pipe 10 of the cool water which it may then contain. After sixty seconds, the drainage operation terminates; and in view of the fact that circulation pump 30 is in operation, water issues forcefully from the

distributors

20 and 23. During the first portion of this operation, the water washes the detergent out of one of the cups of the detergent dispenser 18, whereupon a washing solution is created. During this operation, also, the detergent dispenser prepares itself for supplying detergent to the next washing operation.

At the end of four minutes, cam 87 again closes its drain pump switch 87a for one minute, whereupon the washing liquid is discharged. The circulation pump remains in operation in order to purge the pump casing and associated conduits of most of the spent washing liquid. After the one minute discharge operation, cam 89 closes 7 its switch for another one-minute fill, and there ensues a apogee;

9.. switch 89a also opens, signifying the end of the washing and'rinsing phases of the operational cycle.

As indicated in the cam sequence chart, when the circulation and drain pumps finally terminate their operation-which would be at the end of the nineteenth minute of operationthe cam 38 closes its switch 88a to energize the heater 19. The heater l9 maintains an elevated temperature in the tub to facilitate the air-drying of the dishes and other articles therein. At about the forty-first minute of operation, the timer begins the line switch kickout operation. The kick-out impulse-that is to say, the movement of the line switch to open circuit position actually occurs in the forty-fourth minute. In the meantime, however, cam 92 has closed its switch 92a providing a bypass around the line switch 93; and when said line switch opens, it is without effect as respects the continued operation of the timer motor 85. Said motor remains in operation until the fiftieth minute has passed, at which time the cam 92 has opened switch $201, and thereby has restored the sequence timer to a condition which makes it ready for the next operation of the dishwasher.

The presently commercial embodiment of the dishwasher uses two gallons of water for each of the washing and rinsing operations. The valve 9 is of the well-known type having a flow control device, pursuant to which it delivers two gallons per minute over a range of inlet water pressure from about fifteen pounds per square inch to more than seventy-five pounds per square inch, thus accommodating itself to the range of water pressures found in the average domestic installation. During the first minute of operation, two gallons of water will, therefore, have been discharged by the pump 81; and during the second minute another two gallons will be delivered to the tub andwill be available for the first washing operation. It the drain valve discharge were plugged up, or, if for some reason the pump 80 did not operate during the first minute, the accumulation of two gallons of water during the first minute would operate the switch 14 to open circuit position and no more water could be admitted to the tub. Switch 14 is, therefore, a safety switch to prevent flooding the dishwasher.

As is evident'from the cam sequence portion of FIG. 10, the short cycle cam 91 maintains the line circuit closed for a period which includes two washing and one rinsing operation. This operational cycle is useful, for example, in washing pots and cooking ware, as its primary function'is to loosen and remove stubborn soil and place the pots in condition for a final cleaning by hand or by a later operation of the normal dishwashing cycle. It will be noted that when the short cycle cam opens its switch 91a, all power is interrupted, for the preliminary preparation for the short cycle operation includes operating the switch 95 to open circuit condition. At the end of the short cycle of operation, therefore, the timer has not reached the condition where it has reset itself for reuse. It is necessary for the operator by manipulation of the timer control knob 17 to restore the timer to its home position, in which the respective cam actuated switches, including the switch 91a, are prepared for the next operation.

While there has been described what is at present con sidered to be the preferred embodiment of the invention, it will be understood that various modifications may be made therein, and it is intended to cover in the appended claims all such modifications as fall within the scope of the invention.

I claim:

1. In dishwashing apparatus including a tub having an opening in a wall and a door for said opening and means for supplying said tub with a quantity of washing liquid: a rack to accommodate articles to be washed; means for mounting said rack for movement to or from an operating position in said tub; a first spray nozzle device extending laterally of said rack in parallel spaced relation thereto,

said device having a multiplicity of openings for discharging liquid against articles in said rack; a conduit; means for mounting said spray nozzle device on one end of said conduit in communication therewith; means for mounting said conduit on said rack, the opposite end of said conduit being open and below said rack; a second spray nozzle device, comprising an open ended tubular huh and spray arm means extending laterally therefrom; means for rotatably mounting said second device in said tub below said rack with the hub coaxial with said conduit when said rack is in its operating position, an open end of said hub openly facing said conduit open end in spaced relation therewith, said hub open end being substantially larger in diameter than that of said conduit; an annular resilient coupling member disposed on said hub open end and having an annular wall portion radially inward ofthe hub wall for displacement into mechanical engagement with said conduit end under influence of liquid pressure within said hub, the opening in said coupling member being substantially equal to the conduit diameter for substantially unrestricted flow of liquid from said hub portion into said conduit; means for supplying liquid from said tub to said hub under pressure sufficient to, effect said coupling displacement and in volume to supply both said spray nozzle devices for discharge of liquid therefrom; and means for effecting rotation of said last named spray nozzle device relative to said rack while maintaining said coupling members in engagement with said conduit.

2. Dishwashing apparatus, comprising a tub; means for supplying washing liquid thereto; means including a rack for accommodating articles to be washed; means for removably supporting said rack in an operating position within said tub; a first spray nozzle device, said device including an u anding hub providing an axial discharge opening facing ll bottom of said rack; means for mounting said spray nozzle device for rotation about the axis or" its hub; a second spray nozzle device; a rigid openended conduit fixed at one end to said second spray nozzle device to provide for fiow of washing liquid directly thereinto, said second spray nozzle device extending laterally therelrom for a substantial distance and having a multiplicity of openings for discharging liquid against said rack; bearing means interposed between said rack and said second spray nozzle device at the aids of rotation of for supporting said conduit for rotation relative to said rack while permitting axial displacement of said conduit and associated second spray nozzle device; hub means on said conduit engageable with said rack to position the f ee end of said conduit below said rack in a predetermined vertically spaced axial alignment with the axial discharge opening or" said first spray nozzle device, the hub means on said conduit being arranged to disengage from said rack upon axial displacement of said conduit; a resilient coupling fixed to the hub of said first spray nozzle device concentrically about the axial opening thereof, said coupling having structure assuming an inactive position disengaged from the open end of said conduit out displaceable into mechanical engagement therewith to provide an enclosed flow passage between the hub of said first spray nozzle device and said conduit under a condition of positive liquid pressure within said first spray nozzle device; pump means for supplying liquid from said tub to said first spray nozzle device at the said positive pressure condition; the displacement of said coupling into mechanical engagement with said conduit effecting the disengagement of said conduit hub means from said rack, whereby said conduit is supported by said coupling and said bearing means; and means for rotating said first spray nozzle device relative to said rack.

3. Dishwashing apparatus, comprising structure providing a tub having a wall opening; a closure door therefor; means for supplying said tub with washing liquid; a dishraclt in the lower portion of said tub, a dishrack in the upper portion of said tub; means for positioning said upper and lower racks in vertically spaced operative position while permitting at least the lower rack to be drawn through the tub wall opening; a first spray nozzle device having a tubular hub and at least one spray arm member extending laterally therefrom, means for mounting said spray nozzle device below said lower rack for rotation about the axis of said hub portion; means including reaction-spray means on said arm member for rotating said hub; means comprising an open-ended tubular extension of said hub for discharging liquid axially upwardly therefrom; a conduit having an open end; means for rotatively mounting said conduit on said lower rack with the said open end coaxial with said hub extension and in vertically spaced relation therewith when said lower rack is in operative position; a resilient annular coupling member fixed to the said hub extension for displacement into mechanical engagement with said conduit about the open end thereof under influence of liquid pressure within said hub, the opening of said annular member being smaller than the discharge diameter of said tubular extension and coaxial therewith; a second spray nozzle device, said device having a multiplicity of individual openings disposed in a common plane for discharge of liquid toward said upper rack; means for mounting said second device nonrotatably on said conduit intermediate said upper and lower racks, said second spray nozzle. extending laterally from said conduit in communication therewith; and means for pumping liquid from said tub into said hub and tubular extension thereof under sufiicient pressure to engage said coupling member with said conduit end and in sufficient volume to supply both of said spray nozzle devices; said coupling member providing a driving connection between said hub and said conduit for rotating said conduit conjointly with the first spray nozzle device.

4. In dishwashing apparatus including a tub having an opening in a wall and a door for said opening and means for supplying said tub with a quantity of washing liquid: a rack to accommodate articles to be washed; means for mounting said rack for movement to and from an operative position in said tub; a first spray nozzle device; a con duit; means for securing said device to one end of said conduit for receipt of liquid therefrom, said spray nozzle device extending laterally from said conduit for a substantial distance parallel to the horizontal plane of said rack to discharge liquid against articles therein; means for supporting said conduit on said rack, the other end of said conduit being open and adjacent the base of said rack; a second spray nozzle device, comprising an open-ended tubular hub and spray arm means extending laterally therefrom; means for mounting said second device in said tub with the hub coaxial with said conduit when said rack is in its operative position, an open end of said hub openly facing said conduit open end in spaced relation therewith, said hub open end being substantially larger in diameter than the open end of said conduit; an annular resilient coupling member disposed on said hub open end for displacement into a substantially liquid tight mechanical engagement with said conduit end under influence of liquid pressure within said hub, the opening in said coupling member being smaller than the hub open end to provide a substantial area of said coupling member subject to liquid pressure; means for supplying liquid to said hub under pressure suincient to effect said coupling displacement and in volume to supply both said spray nozzle devices for discharge of liquid therefrom into said tub; and means for effecting rotation of said second spray nozzle device relative to said rack while said coupling member remains in substantially liquid tight engagement with said conduit.

5. Dishwashing apparatus, comprising structure providing an open-front tub having a door swingable between open and closed positions relative to said tub front opening, open-work racks for dishes disposed respectively within the lower portion and the upper portion of said tub and arranged for individual movement through said tub opening to or from an operative position in said tub, a

reaction spray device rotatably mounted in said tub below said lower rack, means for supplying said device with a continuous supply of liquid under pressure to rotate said device and effect the discharge of sprays of liquid throughout said tub, said reaction spray device having an upstanding hub portion provided with an axial discharge opening facing said lower rack, a rigid, open ended conduit supported in said lower rack for free rotation relative thereto, a spray nozzle device fixed to and extending laterally from an end of said conduit below said upper rack for rotation by said conduit in a plane parallel to the base of said rack, said spray nozzle device having individual discharge openings disposed at various radial distances from the axis of rotation thereof to discharge liquid against articles in said upper rack, said conduit providing means for supplying said spray nozzle device with liquid and having its open end disposed, when said lower rack is in operating position within said tub, in vertically spaced axial alignment with the axial discharge opening of said reaction spray device, coupling means fixed on said hub portion about said axial opening in normal vertically spaced relation to the open end or" said conduit, means responsive to the flow of liquid through with hub to displace said coupling means to sealingly engage with said conduit about the open end thereof, whereby during operation of said dishwashing apparatus said conduit and said hub portion form a unitary, rotating, conduit through which liquid is supplied to said spray nozzle device and said conduit is physically disconnected from said reaction spray device when liquid flow through the said hub portion is discontinued, thus under the last-named circumstance permitting the lower rack to be withdrawn from said tub without conflicting with said reaction spray device. 7

6. Dishwashing apparatus, comprising a tub adapted to hold a quantity of dishes and other articles to be washed, a rack for containing said articles, means for mounting said rack for removal from an operating position in said tub, a first spray nozzle device having discharge openings directed toward said rack, means fixed relative to said tub for mounting said device for rotation in a plane be low and parallel to said rack, means including an upstanding, open-ended hub portion for supplying said spray nozzle device with liquid under pressure to discharge liquid against articles in said rack, means for effecting rotation of said spray nozzle device during discharge of liquid therefrom, a second spray nozzle device, means carried by said rack for mounting said second device for axial movement relative to said rack and rotation in a plane above and parallel to said rack, said second spray nozzle device including means providing a water passage extending for several inches laterally of the axis of rotation thereof and having apertures for discharging individual streams of liquid against articles in said rack from different radial distances from said axis of rotation, said mounting means positioning said second device in a predetermined vertically spaced position relative to said first spray nozzle device when the rack is in operative position within said tub, and means fixed to the hub portion of said first spray nozzle device and responsive to the issuance of liquid therefrom to mechanically couple said hub portion to said second spray nozzle device for rotation therewith and to supply said second spray nozzle device with liquid under pressure for discharge through the apertures thereof.

7. Dishwashing apparatus, comprising a tub, upper and lower openwork racks disposed in vertically spaced relation within said tub to contain articles to be washed, means for mounting at least said lower rack for removal from an operating position in said tub, a spray nozzle device disposed within said tub for rotation in a horizontal plane intermediate said racks, said device comprising a fiat, disk-like, structure having a multiplicity of discharge openings disposed throughout a surface of said structure facing said upper rack to direct sprays of liquid toward articles therein, a rigid open-ended tube rotatably mounted in said lower rack, means for aflixing said spray nozzle device to one end of said tube to receive liquid therefrom, means including an upwardly extending conduit disposed Within said tub below said lower rack, said conduit having an open end facing said rack in axial alignment with the bottom of said tube, means for supplying said conduit with a flow of liquid under pressure, means responsive solely to the discharge of liquid from the said open end of said conduit to mechanically connect said tube to said conduit end for establishing a pressure-tight flow passage between said conduit and said tube, and means for effecting the rotation of said tube and spray nozzle device during flow of liquid under pressure thereinto.

References Cited in the file of this patent UNITED STATES PATENTS 2,063,746 Meeker Dec. 8, 1936 Donnelly Mar. 14, 1950 De Lisle May 16, 1950 Marmo et al. July 5, 1950 Sway Jan. 5, 1954 Lengrenis June 7, 1955 Stanitz et a1 Aug. 16, 1955 Oxford Dec. 13, 1955 James Jan. 17, 1956 Federighi Apr. 3, 1956 Sisson June 5, 1956 Low June 26, 1956 Clark July 3, 1956 Low Nov. 27, 1956 Bradley et al. Feb. 26, 1957 Low Mar. 4, 1958 Ullman et a1 June 23, 1959 FOREIGN PATENTS Austria Feb. 10, 1953