US3285779A - Dishwashing apparatus - Google Patents

Description

Nov. 15,1966 A w. DUNHAM DISHWASHING APPARATUS 4 Sheets-Sheet 1 Filed Nov. 17, 1964 INVENH'OR ANSEL W. DUNHAM Filed Nov. 1.7, 1964 4 Sheets-Sheet 2 FIGS.

INVENTOR A NSEL W. DUNHAM ATTYS Nov. 15, 1966 A. w. DUNHAM DISHWASHING APPARATUS 4 Sheets-Sheet 5 Filed Nov. 17, 1964 ATTYS Nov. 15, 1966 A. w. DUNHAM 3,

DISHWASHING APPARATUS Filed Nov. 17, 1964 4 Sheets-S eet 4 FIGS.

INVENTOR ANSEL W. DUNHAM ATTYS.

United States Patent "ice 3,235,779 DISHWASHING APPARATUS Ansel W. Dunham, Napa, Calih, assignor to King Fifth Wheel Company, Mountaintop, Pa., a corporation of Pennsylvania Filed Nov. 17, 1964, Ser. No. 411,741 4 Claims. (Cl. 134-44) The present invention relates to dish washing, and more particularly to commercial dish washing of the type wherein the dishes and other tableware are placed in trays which are put through a dish washing cycle of a relatively short time period. More specifically, the present invention constitutes an improvement upon the invention disclosed in my earlier Patent Number 2,307,363, issued January 5, 1943.

A primary object of the present'invention is to provide an improved dishwasher of the stated type wherein the dish washing cycle is reduced in time to a minimum and yet which is fully elfective to cleanse the tableware both from grease and from food particles which may be ad hered thereto.

More specifically, the present invention provides a dishwasher in which the wash water is cascaded over the tableware in a concentrated sheet which traverses the entire cross sectional area of the dishwasher.

The present invention also provides a dishwasher wherein the rinse water is sprayed over the tableware from above as well as below. and wherein the proportion of rinse water between the overhead and underneath sprays is automatically varied in accordance with the type of the tableware being rinsed.

The present invention provides an improved dishwasher which operates efliciently and effectively to thoroughly cleanse the tableware washed therein in a minimum length of time and with a minimum expenditure of power, avoiding the necessity for high pressure pumps for pressurizing the water used.

All of the objects of the invention are more fully set forth hereinafter with reference to the accompanying drawings wherein:

FIG. 1 is a view in side elevation with portions broken away illustrating a dishwasher made in accordance with the present invention;

FIG. 2 is an end view of the dishwasher shown in FIG. 1

3,285,779 Patented Nov. 1 5, 1966.

bowls, serving dishes, silverware and the like, and the third form may be used for loading tumblers, and similar glassware. Such trays are of standardized outer dimensions to be used interchangeably in the dishwasher, the only difference being in the arrangement of partitions and tableware supports to accommodate the different forms of tableware.

In the operation of the dishwasher, the tableware in the tray 18 is subjected to opposing streams of wash water from above and below respectively. In accordance with the invention, the upper stream takes the form of a sheet of cascading water extending substantially the entire length of the tank andtraversing from side to side therein during the wash cycle. The lower stream is ejected upwardly from a pair of rotating fountain heads mounted in the bottom of the tank. The wash water is recirculated for a period of approximately 40 seconds, the water being maintained at a temperature of approximately 165 F. by suitable heating means in the bottom of the tank. Following the wash period, the circulation of water is interrupted and the tableware in the dishwasher is rinsed by pairs of with portions broken away to illustrate the interior construction thereof;

FIG. 3 is an enlarged vertical cross section through the machine taken on the line 3--3 of FIG. 1 and showing the flow of wash water in the washing period of the cycle.

FIG. 4 is an enlarged horizontal section taken on the line 44 of FIG. 1;

FIG. 5 is a fragmentary vertical sectional view taken on the line 55 of FIG. 1 and showing the flow of rinse water in the rinsing period of the cycle.

FIG. 6 is an enlarged sectional view taken on the line 66 of FIG. 5; and

FIG. 7 is an enlarged sectional view taken on the line 7--7 of FIG. 4 showing the mechanism for causing the sheet of cascading water to traverse the tank.

Referring now to the drawings, the dishwasher illustrated therein comprises an exterior casing 10, mounting therein an interior tank 11 and having a cooperating lid 12 hinged thereto as indicated at 13 (see FIG. 2). The interior tank 11 is generally rectangular in outline and has midway on its side and end walls inwardly projecting brackets 17 for receiving the conventional dishwasher tray 18 into which is loaded the tableware to be washed. The tray 18 may take several forms; for example, one form may be used for loading flat plates, sauce dishes, saucers, and the like. Another form may be used for loading cups,

opposed upper and lower rotating spray arms for a period of from 10 to 20 seconds. The spray arms have outlets directed toward the middle of the tank to provide a spray of rinse water which serves to thoroughly rinse the tableware. When rinsing glassware, cups, silverware, etc., the normal distribution equally divides the rinse water between the upper and lower sprays respectively. However, when washing dishes and other flatware which projects substantially above the bottom of the tray, means is provided to automatically increase the proportion of flow through the upper sprays to approximately 80%, whereby the bulk of the rinse water is sprayed downwardly over the dishes and the like in the tray. When the rinse period is completed, the flow through the rinse spray is interrupted and the lid may be opened for removal of the tray of washed tableware and insertion of a tray of dirty tableware.

Referring again to the drawings, the tank is provided with a wash water inlet 21 controlled by a suitable valve 20 and, if desired, is equipped with a detergent dispenser (not shown), operable to inject a charge of detergent into the wash water during each cycle. The quantity of wash water is maintained below the level of the tray 18 by an overflow pipe 26 projecting upwardly into the tank as shown in FIGS. 1 and 4. A drain is provided at 22. The wash water may be introduced into the tank at standard line pressure and a thermostaticallycontrolled heating element 23 is provided adjacent the bottom of'the tank to heat the wash water to the desired temperature. In the present instance, as shown in FIGS. 3 and 4, the heater 23 comprises a heating loop 24 and a thermostat 25 projecting into the tank from its rear wall. The wash water is circulated by means of an impeller 31 driven by a motor 33 under the bottom of the tank and having a shaft 32 projecting upwardly through the bottom of the tank centrally thereof. The impeller 31 is housed in a hollow cylindrical housing 34 open at its bottom to the tank 11 and open at the top to a manifold 35. The manifold 35 is provided with a pair of oppositely directed passageways 36 and 37 connected at their free extremities to openings 38 and 39 in the side wall of the tank. Ducts 40 and 41 are connected to the openings 38 and 39 and diverge upwardly to connect with orifices 42 and 43 which extend along the length of the tank 11 adjacent its upper end. Thus, as shown by the arrows in FIG. 3, the wash water is impelled upwardly through the passages 36 and 37 and ducts 40 and 41 to provide a stream of wash water which cascades outwardly through the orifices 42 and 43 over the tableware in the tray 18. As indicated, the streams, indicated by the arrows at 44 and 45, meet and cascade downwardly in a sheet 46 extending the full length of the side walls of the tank.

In accordance with the invention, in order to cause the sheet 46 to traverse across the width of the tank, flow control or baffie means is provided. In the present instance, the baflle means comprises proportioning dampers 48 and 49 in the passageways 36 and 37 respectively. The dampers are interconnected so that when one provides maximum flow, the other provides minimum flow and vice versa. Thus, when the dampers are adjusted between their opposite limit positions, the sheet 46 of cascading water resulting from the merger of the two streams 44 and 45, traverses from one side of the tank to the other. In order to adjust the dampers 48 and 49 (see FIGS. 4 and 7), the dampers are provided with arms 52 and 53 operable to engage abutments 54 and 55 mounted on a slide 56 which is slidably mounted on the bottom of the manifold, for example by a .guide 57, for reciprocatory movement. The slide is reciprocated by an arm 58 mounted at one end on the slide 56 and mounted at the other end on a crank pin 59 on a control motor 60, or equivalent drive means. Thus, as the motor 60 rotates the pin 59 the slide 56 is displaced in its guide 57 from one side to the other and back. With reference to FIG. 7, rightward movement of the slide 56 and abutment 54 displaces the arm 52 counterclockwise thereby gradually rotating the damper 48 counterclockwise against the flow of water through the passageway 36, reducing the flow therethrough. In addition, displacement of the slide 56 and abutment 55 to the right permits the water pressure in the passageway 37 to rotate the damper 49 counter-. clockwise thereby opening the passageway 37 and increasing the flow therethrough. Thus, rightward movement of the slide 56 alters the proportion of flow so as to cause the sheet 46 to travel from right to left as seen in FIG. 3. Thereafter, leftward movement of the slide 56 restores the proportion of flow so as to cause the sheet 46 to travel from left to right.

Thus, as the control motor 60 rotates the crank pin 59, the sheet 46 of cascading water traverses back and forth between the opposite side walls of the tank. In this manner, the tableware in the tray 18 is fully subjected to a downwardly cascading sheet of wash water. The tableware is also subjected to upwardly-directed revolving streams of wash water from fountain heads 71 and 72 rotatably mounted on the manifold 35 adjacent the opposite end of the tank. The water from the manifold is directed through the hollow fountain heads 71 and 72, and through upwardly directed openings therein as best shown in FIG. 5. The wash water from the manifold streams upwardly through the ports 73 and 74 in the heads 71 and 72 to provide concentrated streams of wash water to impinge against the undersurface of the tableware in the tray 18. The fountain heads 71 and 72 are rotated by the discharge of water through apertures 75 and 76 in one of the arms of the fountain head. The discharge of water from the apertures 75 and 76 causes the fountain heads 71 and 72 to rotate in a clockwise direction as indicated by the arrows 71a and 7211. Thus, the under-portion of the tableware in the tray 18 is thoroughly washed by revolving streams of upwardly directed wash water from the rotating fountain heads. In this way, the tableware is subjected to heavily concentrated streams both from above and from below to thoroughly cleanse food particles and the like therefrom.

Following a wash period of sufficient duration to cleanse the tableware, in the present instance 40 seconds, the rinse water is sprayed over the tableware. To this end, rinse arms are provided above and below the tray 18. As shown in FIG. 4, the lower rinse arms are designated 81 and 82, and as shown in FIG. 1, the upper rinse arms are designated 83 and 84. The rinse arms are identical in construction and only one will be described, in the present instance, the arm 82. As shown in FIG. 5, the arm 82 is hollow and has a series of orifices 85 disposed along its length in the upper surface thereof. At each end, the arm is provided with a nozzle 86 which operates when rinse water is expelled therethrough to effect clockwise rotation of the arm (see FIG. 4). The arm is mounted on a hollow tubular shaft 87 having a series of apertures in registry with the hollow center of the arm so that as the arm rotates on the shaft, water from the hollow bore thereof is introduced into the arm from which it is sprayed through the orifices '85 and nozzles 86. The hollow shaft 87 connects at its lower extremity to a valve housing 88 having a valve element 89 therein (see FIG. 6) with a stem 90 passing upwardly through the shaft 87 to project above the rinse head 82 as shown in FIG. 5. A similar hollow shaft 91 is provided for the rinse arm 81 which is closed at its upper end and is connected at its lower end to a conduit 92 connected to the valve housing 88 as shown in FIG. 6. Rinse Water is supplied to the housing 88 by a rinse water supply duct 95. The hollow shafts for the spray arms 83 and 84 in the lid 12 of the tank are connected through conduits 93 and 94 (see FIGS. 1 and 2) to the rinse water supply duct 95 below the latters connection to the valve housing 88. At its opposite end, the supply conduit 95 is connected to a rinse tank 96 having a thermostatically-controlled heating element 97 therein and being connected to a fresh water supply line 98 having a control valve 99 therein.

In the operation of the dishwasher, after the completion of the wash period, the valve 99 is opened, placing the rinse tank 96 under line water pressure. The water pressure causes the heated rinse water to flow through the conduit 95 and from there to the upper rinse arms 83 and 84 through the conduit 94 and into the valve casing 88. The water pressure causes the valve element 89 to lift from its illustrated full line position in FIG. 6 to the broken line position, thereby affording flow of the rinsewater into the rinse arms 81 and 82 through the conduit 92 and the hollow shaft 87 respectively. Under these conditions, the rinse water is approximately equally divided between the upper rinse arms and the lower rinse arms so that half of the rinse water is discharged through the rinse arms 81 and 82 and the other half through the rinse arms 83 and 84. This is desirable when rinsing cups, flatware, and the like.

In accordance with the invention, means is provided to automatically reduce the proportion of the rinse water flowing through the lower rinse arms 81 and 82 when rinsing dishes. To this end, the dish racks which are used when washing plates and the like are provided with control elements or clips 118 positioned to register with the valve stem 90 when the plate rack 18 is placed on the brackets 17 facing either direction. One of the clips 118 thereby displaces the valve stem 90 downwardly against the pressure of the water in the casing 88 to the full line position of FIG. 6. In this position, the valve element 89 limits the water fiow into the casing such that only approximately 20% of the rinse water is sprayed through the lower rinse arms 81 and 82, the remaining 80% being sprayed through the upper rinse arms 83 and 84. In this way, in situations where upwardly directed rinse water is not required, and it is desired to have substantialflow of rinse water in the upper reaches of the tank, the bulk of the rinsing is accomplished by downwardly directed sprays from the upper rinse arms. A rinse period of from 10 to 20 seconds has been found sufficient to thoroughly rinse the tableware in the tray 18, after which the valve 99 is closed, whereupon the lid of the dishwasher may be opened and the tray removed to complete the entire cycle. In order to prevent leakage from the dishwasher during the wash and rinse periods of the cycle, the lid 12 is tightly fitted on the tank 14. To accommodate the expansion of air when the temperature in the tank is raised, a suitable vent 114 and shield 115 (see FIGS. 1 and 4) is provided in the front wall alongside the upwardly divergent duct 40. Additional vents may be provided for installations where the expansion will be especially violent, for example when the washer cycle is .to be initiated after prolonged idle periods, when the unit is quite chilled.

The controls which sequentially operate the wash water inlet valve 20, the impeller motor 33, control motor 60, and the rinse water inlet valve 99, may be of conventional construction. Normally, the wash water in the tank maintains the proper washing temperature through the addition of the heated rinse water at the end of each wash period, and the rinse tank is normally heated to the desired level during the wash period. However, when starting with cold water, suitable controls delay the operation until the proper temperatures are attained.

It should be noted that the wash water remains in the tank at a level below the tray 18, over several cycles and is drained by removing the overflow pipe 26 from the drain opening 22 onlywhen the wash water is overly dirty, or when the machine will be shut down for a prolonged period. This efi'ects a considerable saving of wash water, in that the only water lost during each cycle is the amount used during the rinse portion which is discharged through the overflow 26, along with any garbage particles which may float on the surface of the wash water.

While a particular embodiment of the present invention has been herein illustrated and described, it is not intended to limit the invention to such disclosures, but changes and modifications may be made therein and thereto within the scope of the following claims:

I claim:

1. In a dishwasher having a tank having coextensive orifices in opposite side walls adjacent the top and disposed along the length thereof, means in said tank to support a rack for tableware therein below said orifices, a manifold, impeller means operable to circulate wash water from the bottom of said tank into said manifold, duct means connecting said manifold to each of said orifices whereby upon operation of said impeller means said wash water is expelled from said orifices in confronting streams coextensive with said orifices, said streams merging along a line into a cascading sheet of wash water intermediate said opposite side walls, flow control means to determine the line of merger of said streams, and actuating means for said flow control means to cause said line of merger and therefore said cascading sheet to traverse the space intermediate said side walls; the improvement wherein said flow control means comprises baffles mounted to intercept the flow from said impeller and through said orifices, one battle for each side wall, means interconnecting said bafiles for countermovement, and drive means to catuate said baflles to cause said cascading sheet to traverse back and forth between said opposite side walls.

2. A dishwasher according to claim 1 wherein said manifold is provided with two outlet passageways, one for each orifice, said duct means comprise separate ducts, and said bafiles are pivotally mounted in said manifold outlet passageways to vary the flow through the associated orifice between a minimum and a maximum, the connection providing minimum flow through one orifice concurrently with maximum flow through the other.

3. In dishwashing apparatus comprising a tank and means to circulate wash water through said tank in streams to wash the tableware therein, spray means for spraying rinse water over the tableware, said spray means comprising upper and lower spray arms disposed respectively above and below the tableware in the tank, a common supply for said rinse water, separate conduits from said supply to said upper and lower spray arms respectively, a proportioning valve connected to said supply and I operable to vary the proportional flow between said upper and lower spray arms, and an operator for said valve to vary the proportional flow when the character of the tableware being washed and rinsed is changed, a plurality of trays for tableware; the improvement wherein at least one tray has a control element thereon, said apparatus including means to support each of said plurality of trays in said tank intermediate said upper and lower spray arms, said operator for the valve being positioned for registry with said control element of said one tray whereby upon engagament of said one tray on said support means, said control element actuates said operator to operate the valve to thereby change the proportional flow.

4. Dishwashing apparatus according to claim 3 wherein said valve comprises a valve casing in said supply conduit for the lower spray arm, a valve element in said casing operable in one limit position to aflord maximum flow therethrough and operable in the other limit position to afford minimum flow therethrough, said operator comprising a valve stem connected to said valve element and displaceable by said control element to position said element in one of said limit positions.

References Cited by the Examiner UNITED STATES PATENTS 821,250 5/1906 Miller 134-176 X 1,023,630 4/ 1912 Elkins 134-44 2,236,791 4/ 1941 Forsberg 134183 2,307,363 l/ 1943 Dunham 13499 2,597,359 5/1952 McDonald et a1 13457 FOREIGN PATENTS 104,057 3/ 1924 Switzerland.

References Cited by the Applicant UNITED STATES PATENTS 1,6-24,3 81 4/ 1927 Barker. 2,307,363 1/ 1943 Dunham. 2,563,109 8/ 1951 Franklin. 2,597,359 5/ 1952 McDonald. 2,608,981 9/1952 Jackson. 2,824,648 2/ 8 Bear. 3,101,728 8/ 1963 Broge.

CHARLES A. WILLMUTH, Primwry Examiner.

R. L. BLEUTGE, Assistant Examiner.

Claims (1)

1. IN A DISHWASHER HAVING A TANK HAVING COEXTENSIVE ORIFICES IN OPPOSITE SIDE WALLS ADJACENT THE TOP AND DISPOSED ALONG THE LENGTH THEREOF, MEANS IN SAID TANK TO SUPPORT A RACK FOR TABLEWARE THEREIN BELOW SAID ORIFICES, A MANIFOLD, IMPELLER MEANS OPERABLE TO CIRCULATE WASH WATER FROM THE BOTTOM OF SAID TANK INTO SAID MANIFOLD, DUCT MEANS CONNECTING SAID MANIFOLD TO EACH OF SAID ORIFICES WHEREBY UPON OPERATION OF SAID IMPELLER MEANS SAID WASH WATER IS EXPELLED FROM SAID ORIFICES IN CONFRONTING STREAMS COEXTENSIVE WITH SAID ORIFICES, SAID STREAMS MERGING ALONG A LINE INTO A CASCADING SHEET OF WASH WATER INTERMEDIATE SAID OPPOSITE SIDE WALLS, FLOW CONTOL MEANS TO DETERMINE THE LINE OF MERGER OF SAID STREAMS, AND ACTUATING MEANS FOR SAID CONTROL MEANS TO CAUSE LINE OF MERGER AND THEREFORE SAID CASCADING SHEET TO TRAVERSE THE SPACE INTERMEDIATE SAID SIDE WALLS; THE IMPROVEMENT WHREREIN SAID FLOW CONTROL MEANS COM-

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