US2654377A - Dishwashing machine - Google Patents

Description

Oct. 6,1953 Q SWAY DISHWASHING MACHINE 3 Sheets-Sheet 1 Filed Feb. 9, 1949 Inventor: Henry C. Swag, M

Hi5 Attorney H. C. SWAY DISHWASHING MACHINE Oct. 6, 1953 3 Sheets-Sheet 2 \nventow Henry C. sway.

His Attovney.

Filed Feb. 9, 1949 x M k x llllltilllllllli \M|I..||||| A 1 v 1953 H. c. swAY DISHWASHING MACHINE 3 Sheets-Sheet 3 Filed Feb. 9, 1949 His Attorney.

3 dropped during the loading of the machine, from fouling the impeller.

In a dishwasher of the impeller type, it is preferable to arrange the motor 21 so that its shaft 4| will extend vertically upwardly concentric with the tub 28. A sleeve or bearing 42 for the motor shaft may be integral with and extend upwardly from the lower wall 43 of the pump chamber 44. It will be understood that suitable seals (not shown) protect against contamination of the wash water with lubricant and prevent water from passing into the motor. Advantageously, the pump chamber is formed as part of the motor housing and afiords means of securing the housing to the bottom of the tub, as by screws 45 or equivalent. It will be understood that gaskets and other leakage-preventing means are provided to seal the aperture at the bottom of the tub. Sleeve 42 extends upwardly to a point substantially above the static water level, WL, and at its upper end is provided with suitable water sealing means (not shown). Fixed to the upper end of the shaft ll is a tubular hub'structure 46 which extends about the bearing 42 in concentricity therewith. Suitably secured to hub it-advantageously integral therewith-is a pump impeller 4'! which, as later explained, pumps water outwardly through the discharge conduit 48 to the discharge control valve 50 and thence to the drain connection 2 3. Also afiixed to the motor shaft and carried by the upper end of the pump hub is the hub SI of the impeller 52. The impeller and its hub may be molded from rubber compounds or plastic materials which are satisfactorily abrasion resistant. The impeller blades have a sharp angle of attack as is apparent in Fig. 2 and the motor and impeller are capable of substantial water movementfor example, at the rate of 50 gallons per minute.

A present embodiment of a dishwasher embodying the present invention operates most satisfactorily on one gallon of water, said quantity filling the lower portion of the tub to a point wherein the impeller 52 is approximately onehalf submerged. A feature of the invention resides in the use of a chamber associated with the cover to measure the water with substantial accuracy. As appears to best advantage in Fig. 2 the water chamber may be formed by the cover itself, by making the cover of hollow construction, in which an upper member 53 which is shaped to form a convex top wall and cylindrical side wall cooperates with a contoured bottom wall 54 suitably secured to the member 53. Preferably the point of securement is at an outwardly extending peripheral lip 55 which forms an anchor for gasket 55 which seats on a ledge 51 of the tub when the cover is closed. The central portion of the bottom wall 54 is domed as at 58 and at its center is provided with an opening 59. Said opening is partly closed by a baffie 60 which is supported by a bracket 6| afifixed to the cover member 53, said shield having any desired number of side wall openings 69a. The inflow hose 23 seats telescopically about a rigid inlet pipe 62 which enters a side wall of an upper hinge cover plate 63, and then extends into the cover chamber, terminating at any suitable location therein. In the illustrated embodiment the pipe 52 is illustrated as being in contact with the underside of the cover member 52, thereby being suitably above the maximum cover water level, C. W. L., to provide an air gap sufficient to prevent back siphonage from the cover to the fill line. The end of the pipe may be bafiled or the pipe provided with bridge means or the like for supporting it within the cover, as a matter of choice. As best appears in Fig. 3 an opening in the bottom cover member 54 is provided with a plate-like structure 64 which defines a valve seat 65 extending upwardly into the cover. Said valve seat cooperates with a valve disk 66 to permit the cover chamber to be filled, or drained into the tub according to the operating position of the disk. An open-topped detergent cup or container 6'! fits snugly against the underside of plate 64, and forms a conduit through which water flows from the cover into the tub. Suitable side wall channels of container 6! (not shown) engage with side tracks (58 to removably support the container 6! on the plate M. Preferably, the cup is of molded plastic or like lightweight material.

The filling and draining of the cover chamber is controlled by a sliding valve operator iii having an end portion which extends upwardly through a slot in the cover handle II, to terminate in' a suitable knob 12. A bracket 13 provides a supporting saddle M for the rod 10 and also a detent plate 15 for cooperation with the roller- 7 provided detent member 16 afiixed to the vertical portion of rod 18.

Such construction is detailed in Fig. 5. As is apparent from Fig. 3 the detent rollers will climb over the shoulders formed in detent plate 15 during movement of the valve rod to the left or right and seat in the adjacent valley to retain the valve rod in one or the other position. It is understood, of course, that the detent member 16 is springable so as to permit the rollers to ride over the shoulders. Valve disk is advantageously supported on on arm 11 having an apertured head structure through which the mushroom end 18 of the valve disk structure extends. The valve disk structure has a suitable degree of adjustment relative to the arm l! to insure secure seating on seat 66. Arm TI is biased into rotation in valve seating direction by such means as a leaf spring 80 suitably secured as suggested in Fig. 3. The leaf spring forms the double function of biasing the valve as aforesaid and supporting it in proper position relative to the valve seat. Arm 1! is forked atits upper end to slidably receive the rod 10, said rod having a short cross pin 8| which is immediately to the right of the arm 11 as viewed in Fig. 3. It is obvious that when the control knob 12 is pushed leftwardly to the dotted position of Fig. 3, the pin 8| will enforce a counterclockwise rotation of the arm 11 to unseat the valve disk 61 and thereupon permit the water to drain into the tub. It will be noted that the cover is vented through one or more ports 82 so that drainage will be free and unimpaired. The vent ports may be covered by suitable rearward extension 83 of the handle H. As appears best in Fig. 1 the extension 83 provides a suitable plurality of relatively narrow air inflow passages.

' orifice I I6 through which the water flows to the impeller. The ring therefore meters water flowing to the impeller, and prevents any substantial amount reaching the impeller above the base thereof. The metering ring effectively reduces the surging which occurs if the water is allowed to circulate freely into the impeller. It will be noted that the ring fits relatively closely about the impeller, at the low point of the bottom of the tub. Thus, after the quantity of water within the ring has been thrown upwardly by the impeller, water flows to the impeller substantially only through the orifice HE. A metered flow of water to the base of the impeller is thereby enforced. The metering ring effectively reduces the critical effect of the quantity of water within the tub. It has been demonstrated that the water quantity may be doubled--increased to two gallonswithout overloading the motor.

After the desired washing period the tub is drained by returning the control handle to the fill-drain position. The movement of the control rod 10 lifts the valve stem 82 so that the valve disk assembly of the discharge valve 50 is free to lift. It should be understood that all during the washing operation the pump impeller 41 has been rotating inasmuch as it is fixed to the motor drive shaft 4] in common with the impeller hub However, the outlet valve 50 has been held closed by means of the spring 92 and the pump impeller has been rotating idly within the pum chamber; but as soon as the valve stem 92 is raised the pump pressure lifts the valve disk and permits water to flow outwardly through the connection 24 to the discharge port of the faucet fitting. To improve the flow of water into the pump casing, I form the pump cover 502, see Fig. 10, with a central cavity or sump I II at the center of which is an upwardly extending circular wall I I8. Extending tangentially from said wall to the periphery of the cover are vanes I2 and l2l, said vanes being approximately the height of the wall H8. In the cover portion defined by the two vanes I20, I2I the pump cover is slotted to provide an arcuate inlet port I22 at the base of the circular wall II 8. In the space between vane I2I and a third tangentially extending vane I23 there is no bottom wall opening because said space is adjacent to the discharge or high pressure area of the pump housing. Accordingly, vane I23 terminates short of the ring H8 to provide a flow passage I24 into a cover area defined by the vanes I23 and I20, in which area there is another slot, I25, communicating with the pump chamber. I22 and I25 are in the low pressure area of the pump chamber farthest removed from the discharge port. The slot size is such that water will drain rapidly from the tub, but objects which might damage the pump are prevented from entering.

Centrifugal pumps previously used with dishwashing machines and the like have had an inlet openin or openings extending about the full hub circle. In such constructions, noisy splashing and expulsion of water occur through the opening every time a pump blade passes the cutoff point at the outlet. In dishwashers, this undesirable characteristic is most apparent when the pump is operating at the end of the drain cycle. It should also be considered that in dishwashers, this splashing and noise could be of considerable magnitude, for in adapting a centrifugal pump to a desired tub construction it is impossible to have the inlet passage at the very cen- It will be apparent then that the slots ter of the pump cover as in the conventional centrifugal pump design. My pump cover construction as shown herein substantially eliminates the splashing and expulsion of water by blanking off the pump cover over the high pressure area of the pump, as explained above. The present pump cover also provides an improved inflow condition at the pump inlet; the tangential vanes nullify the natural vortex action of the incoming water which might otherwise detract from the proper functioning of the pump. The absenc of an inlet port adjacent to the high pressure cutofi point prevents a conflicting flow of water, thus also minimizing the noise when operating with only residual water in the pump cavity.

The operation of the outlet valve is particularly effective in that the free action of the valve seat assembly operates as a check when the motor is stopped, to prevent the water in the drain tube 48 from flowing back into the pump cavity and the bottom of the tub. At the end of the drain cycle when the last of the water is being emptied from the tub, air begins to enter the pump. At this moment, the tube 48 is full of water by virtue of the pressure created by the revolving pump blades accelerating the water. Air, however, cannot be accelerated with equal facility by the pump blades and the pressure at the base of this vertical water column falls off. Without the free Valve seating action of the valve 50, water would drain back into the pump chamber until enough water (and resultant pressure) accumulate to again force the water up the tube. A cyclic surging action would result, creating a noise that would be disturbing to the operator. However, the valve seat is free to close when the Water flow ceases and by preventing air from entering, the water is held in tube 48 until enough pressure is created by the pump to lift the valve seat assembly. Thus, although the final drainage from the tub may be intermittent, the disconcerting surging noise is not present.

While I have shown a particular embodiment of my invention, it will be understood, of course,

that I do not wish to be limited thereto since many modifications may be made; and I therefore contemplate by the appended claims to cover any such modifications as fall within the true spirit and. scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a dish washing machine, a tub having a depending bottom wall portion at its lower end which defines an impeller chamber, an impeller in said impeller chamber for circulating water from such chamber throughout the tub and from which it flows back to such chamber, a closure for the upper end of the tub having top and bottom walls which define a water chamber, a. wall projecting upwardly from said bottom wall which defines an overflow passage through said bottom wall and serves to define a liquid level in said water chamber, an opening in said bottom wall through which liquid in said water chamber may flow directly to said impeller chamber whereby a volume of wash water measured in' said water chamber may be supplied to said impeller chamber, a discharge conduit connected to the bottom of said impeller chamber, an inlet valve for closing said opening, means connected with said valve for opening and closing it, and a conduit connected to said water chamber through which water may be supplied to it.

2. In a dish washing machine, a tub having a a ree conical bottom wall portionatrits lower endwhich; cflaesam mpeHe e ,-,an-.-im e1 er-in said impeller; chamber for circulating water from-such chamberthrpughout the tub and-from which. it flaws a tozsu h mber, at lqsure fom he ppgreendoigthe tub havingtqp and bottom :wa ls whi htd neza w t r mb r cwa present n upwardly ,irom said bottom wall which defines-an overflow passage through said bottom wall- ;and env sito defin al quid l velrin a d w erscham bet; :anzopening in said bottom'wall,throughrwhich liguid in said watcr chamber may flow; directly toizsaid impeller chamber whereby a volumeof washwater measured in said water-chambermay be supplied to ,saidimpellerphamber, a discharge conduit connected -'-to the bot-tom'of said impeller chamber, an inlet valvetforclosin said openin anwoutletwalve. .for, .theidischargeiconduit; ,means connected to: said. .valves which when \onerated effects the opening of one of said valves and the closing of the other, and a conduit connected to said water chamber through which water may be supplied to it.

3. In a dishwashing machine, a tub having a depending bottom wall portion at its lower end which defines an impeller chamber, an impeller in said impeller chamber for circulating water from such chamber throughout the tub and from which it flows back to such chamber, a hinged closure for the upper end of the tub having top and bottom walls which define a water chamber, a wall projecting upwardly from said bottom wall which defines an overflow passage through said bottom wall and serves to define a liquid level in said water chamber, an openin in said bottom wall through which liquid in said water chamber may flow directly to said impeller chamber, whereby a volume of wash water measured in said water chamber may be supplied to said impeller chamber, a detergent receptacle connected to the under side of said bottom wall in line with said opening, a discharge conduit connected to the bottom of said impeller chamber, an inlet valv for closing said opening, means connected with said valve for opening and closing it, and a conduit connected to said water chamber through which water may be supplied to it.

4. In a dish washing machine, a tub having an impeller chamber at its lower end, an impeller in said impeller chamber for circulating water from such chamber throughout the tub and from which it flows back to such chamber, a closure for the upper end of the tub having top and bottom walls which define a water chamber, a wall projecting upwardly from said bottom wall which defines an overflow passage through said bottom wall and serves to define a liquid level in said water chamber, an opening in said bottom wall through which liquid in said water chamber may flow directly to said impeller chamber whereby a volume of wash water measured in said water chamber may be supplied to said impeller chamber, a drain pump having its inlet connected to the bottom of said impeller chamber, a discharge conduit which extends upwardly along the side of said tub with its lower end connected to the drain pump outlet, an inlet valve for closing said opening, an outlet valve for the upper end of the discharge conduit, means connected to said valves which when operated effects the opening of one of said valves and the closing of the other, and a conduit connected to said water chamber through which water may be supplied to it.

5. In a dish washing machine, a tub having an open top, a hinged cover for the open top com- 1&6 primer-t p; and-bat en wa ls. wl cha efinse a Waterichamben means taic tm lunwardlyi r mi said bottom; wall; Wh htdefiues, anhov rhoiv pen whereb aameasure ivo umee t, Water. ay e supplied ,torsa d. Water hamber, a bane plateeca ried.by;s idcbqttomn alli beneath. said: overflow opening for distributing water overflowing therethrough over dishes in said tub whereby ermay b ,eiv n,..an init al.. a botto chamber, an'impeller initheiimpellenchamber for circulating water over dishes in;the tub, angopen ing, inlthe,bottom wall of the,cover; throug=h:Which a volume ot water measured inth'e water1 h bemmag be supplied directly,,tothecimpeller chamber, a valve for closing,saidmpening means for? operating said valve, a water supply conduit enn c e -do said water chambe andchargeicpnduit connected to theebottom;-, impeller chamber.

6. In a dish washing machine, a tub having an open top, a hinged cover for the open top comprising top and bottom walls which define a water chamber, a water supply conduit connected thereto, means projecting upwardly from said bottom wall which defines an overflow opening whereby a measured Volume of water may be supplied to said water chamber, a bottom wall for the tub shaped to define an impeller chamber, an impeller in the impeller chamber for circulating water over dishes in the tub, a supply opening in the bottom wall of the cover through which a volume of water measured in the water chamber may be supplied directly to the impeller chamber, a drain pump having its inlet connected to the bottom of the impeller chamber, a discharge conduit for the pump, the discharge end of which terminates adjacent to said cover, an inlet valve for closing said supply opening, a discharge valve for closing the end of said discharge conduit, and an operating member carried by the cover for controlling said valves which when moved to one position effects the opening of one of said valves and the closing of the other and when moved to another position effects the opening of the other of said valves and the closing of the one valve.

'7. In a dish washing machine, a tub having an open top, a hinged cover for the open top comprising top and bottom walls which define a, water chamber, a water supply conduit connected thereto, means projecting upwardly from said bottom wall which defines an overflow opening whereby a measured volume of water may be supplied to said water chamber, a bottom wall for the tub shaped to define an impeller chamber, an impeller in the impeller chamber for circulating water over dishes in the tub, a supply opening in the bottom wall of the cover through which a volume of water measured in the water chamber may be supplied directly to the impeller chamber, a drain pump having its inlet connected to the bottom of the impeller chamber, a discharge conduit for the pump, the discharge end of which terminates adjacent to said cover, an inlet valve for closing said supply opening, a discharge valve for closing the end of said discharge conduit, a valve control member which in one position holds the discharge valve closed and in another positionpermits it to be opened by pressure in the discharge conduit, and an operating member carried by the cover for controlling said inlet valve and said valve control member which when moved to one position effects the opening of said inlet valve and move- 1 1 ment of said valve control member to close the discharge valve and when moved to another position efiects the closing of the inlet valve and the movement of said valve control member away from said discharge valve whereby it may be opened by pressure in said discharge conduit.

HENRY C. SWAY.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 954,879 Ostrom Apr. 12, 1910 1,105,561 Hershey July 28, 1914 1,196,862 Hayes Sept. 5, 1916 1,487,426 Andrews Mar. 18, 1924 1,505,492 Reddig Aug. 19, 1924 1,645,815 Murdoch Oct. 18, 1927 1,722,272 Buck July 30, 1929 Number Number Name Date Dunham May 13, 1930 Pauly Oct. 25, 1932 Pauly Oct. 25, 1932 Snyder et a1 Mar. 26, 1935 Stoddard May 21, 1935 Chandler June 13, 1939 Clark et al Sept. 2, 1941 Moody May 12, 1942 Balcunas June 23, 1942 La Bour July 28, 1942 Ballentine Feb. 29, 1944 Voris Dec. 11, 1945 Loeb Feb. 26, 1946 FOREIGN PATENTS Country Date Great Britain Nov. 5, 1937 Switzerland Sept. 15, 1949

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