US2862510A

US2862510A - Dishwasher

Info

Publication number: US2862510A
Application number: US529489A
Authority: US
Inventors: Russell C Geiger; David A Meeker
Original assignee: Hobart Manfacturing Co
Current assignee: Hobart Manfacturing Co
Priority date: 1955-08-19
Filing date: 1955-08-19
Publication date: 1958-12-02
Anticipated expiration: 1975-12-02
Also published as: GB801192A

Description

Dec. 2, 1958 R. c. GEIGER ETAL 2,362,510

DISHWASHER V Filed Aug. 19, 1955 A- 2 Sheets-Sheet 2 INVENTORS `20 RUSSELL c. GEIGER a BY DAVID A. Ml-:EKER WM@ M, M,

AT TORN EYS United States Patent 2,862,510 DrsrrwAsni-:R

Russell C. Geiger and David A. Meeker, Troy, Ohio, assignors to The YHobart Manufacturing Company, rIroy, Ghia, a corporation of hio Application August 195, 1955, Serial No. 529,489 3 Claims. (Cl. 134-111) water is recirculated for a time suflicientto lloosen and remove the food particles on the- ,dishes, such particles being carried along withythe wash liquid. Whilel it is importantl to provide for such uid recirculation, ,it is undesirable to allow the food particles themselves to be recirculated, particularly larger sized food particles and leafy material, and it is also: important to assure that such large sized particles are flushed away when the dishwasher is `drained following the washing cycle and in advance of the rinsing operations. In addition, it is desirable to facilitate access to and removal ofv the mechanical working parts and the drive motor of the dishwasher in the event that servicing thereof is required.

It is a primary objectfof the present invention to provide a dishwasher for household use which operates according to the general principles outlined-above and which is of improved and simplied construction affording major advantages of economy of manufacture and assembly as well as of easy and convenient maintenance.

Another object of thefinvention isto provide a dishwasher of the above general type incorporating a rotating wash arm for spraying `the wash and rinse liquids against the dishes wherein the wash arm rotated by the reactionforces of-tl'ie liquid sprayed-therefrom is mounted directly on a centrifugal pump in vertically aligned relation with` the shaft for the pump impeller, and' a furtherobject of the invention isto provide such a dishwasher construction wherein the drive -motorfor-the pump is suspended below the sump ofV the dishwashingY chamber-in verticalv alignmentwith the impeller 'shaft and in such manner as to bei easily removed for servicing.

Anadditional object of the" invention is to yprovide a` centrifugal'pumpfconstruction for use in a dishwasher of the above type wherein Vthe upper endY of- `the pump housing-forms a support for the hollow hub-of the rotating wash'arrn, wherein'the pump-impeller is mounted in the-pump housing onan axis vertically aligned with the` axis of the wash arm, and wherein the discharge from the-1 impeller `is channeled by vpassageways in the Vpump housing upwardly and into a common passage above and coa-xial with the impeller. Y

It isf also an object 'of theinvention toy provide an improved and simplified strainer construction` for a dishwasher ofthe above outlined type -wherein a major part of 'the strainer 'has relativelyV small perforations for preventing passageof food particles, a minor part of the strainer has relatively large perforations and is arranged both to pass large food particles directly to a trapping space adjacent the drain -valve and also to serve asV a separately vremovable tray for retaining'excessively large food particles, leafy material and the like, and

2,862,510 Patented Dec. 2, 195s the vminor strainerpart also includes askirt of screen material having small perforations and serving to screen thev particle-trapping space from the inlet to the pump housing. f

Otherobjects and Aadvantages of the inventionv will beapparent from the following description, the accompanying drawings and the appended claims.

in the drawings.-

Figi l is asomewhat diagrammaticy view showing a dishwasher constructed in. accordance with `the invention viewed from Ithe side-and with portions of the cabinet broken away to'illustrate details ofinternal construction;

Fig. 2 is an enlarged view invvertical section looking in the Vsame directionas Fig. l and taken generally on the line 2-.2 of Fig. 3; y t

Fig. 3 is a plan view, partly in section, ytaken as indicated by the line 3-3 in Fig. 2;, v

Fig. 4 is an enlarged fragmentary view taken in section on the line 4.?4 of Fig. 3;

Fig. 5 is a detail section through lthe lower pump housing taken as indicated by the line 5-5 of Fig. 3;

yFig.v 6 is a fragmentary `view taken as indicated by the line 6--6 of Fig. `2; andf Fig. 7 is a view yona small scale looking downwardly toward thebottom of the washingv chamber in Figs. l

. and 2 and withy the, wash armand strainer assembly removed.

Y. Referring to-the drawings, which illustrate a preferred embodiment oftheinventiom the dishwashershown in Fig. vl is-v generally similar toqthedishwasher construction shown inv Meeker et al.- Patent 2,681,658 issued June 22,, V195,4l to, thel assignee of the present application. This dishwasher; includes an outer cabinet indicated generally at V10 andhaving a door 11 at the front thereof whichhas a handle 1 2/and is hinged for movement on a horizontal axis to swing downwardly to the open position shownin dottedlines in Fig. l, thedoor having a springcounterbalance 13. Within the cabinetl 10 is the washing chamber wherein the dishes are supported by one or more trays 15,`which may be mounted and operated as described inthe, above Meeker et al. patent.

The bottom- ,ofi-the washing chamber is formed b y a casing 20 havingv a depending; central vportion 21 of circular4 sectionV which forms the sump 22, below the washing chamber.` Thepbottom of the casing portion2-1' has two openings therethrough, a central circular openingI 24. and a generally..kidney-shapedcopening 25 .located forwardly of thel central opening-24 ,and separate therefrom. This-opening25 deiines .xt he. drain outlet passage from the sump 221and;.leads to the drain vvalveassembly described in detailhereinafter. The motor support plate 26 overliesthecasing portion 21sand1includes a flange 27 extending downwardlyithroughsthe opening 25.

The drive motorv for4 effecting circulation of the wash andrinse liquids withinthewashing chamber is indicated generally at 30, and it includes a casting 31 which forms a part of the cover for the motor :parts and additionally actsbcth as a mounting bracket for: the ,motor and also. as a part ofthe drain outlet system. The ycasting 31 includes a top bossV portion 32 which is received through the opening 24,-andvthis casting is secured to the Vcasing 20 by means of'a plurality of screws 33 threaded intothe upper surface of casting 31, suitable gaskets .34being provided to seal this connection. The casting 31 also includes an extension 35' at thev front thereof which encloses a passageway 36jhavinga kidney-shaped opening at its upper end matching the opening 25 in casing portion 21, and -thepassagel is decreasing dimensions towards its vlower endend terminatesin a., cyli 1 1d rif:a l opening 37`having a tapered'valve seat 38 at the frontv thereof.

The centrifugal pump for circulating the wash and Y' rinse fluids in the washing chamber includes lower and

upper housings

40 and 41 respectively which are mounted in superimposed relation directly on the boss portion 32 of the casting 31 and are secured thereto by elongated machine screws 42. The lower pump housing 40 includes an inlet chamber 44, and four of inlet passages (Figs. 2 and 5) lead into chamber 44 at the junction between housing 40 and the top of casting 31. The inlet passages 45 are formed by four feet 46`which supports receive the screws 42 and housing 40 on casting 31, and the inlet passages thus extend around substantially the entire periphery of the housing 40. The inlet chamber 44 in turn leads into the pumping chamber 47 in the upper part of housing 40 wherein the centrifugal impeller 50 operates. The wall of the pumping chamber 47 includes a plurality of curved shoulders 51 which define diffuser passages for conducting the discharge from the impeller and the pumping chamber 47 upwardly to four passages 52 in housing 41 which are separated by ribs 53 and lead upwardly and inwardly to a centrally located outlet passage 54 in the upper end of pump housing 41.

The impeller is mounted on the upper end of the drive shaft 55 of motor 30, which is supported in the pasting 31 by a bearing 56 and shaft seal 57. Special provision is made for preventing any liquid leaking past the shaft seal 57 from reaching the interior of the motor. The casting 31 includes a chamber 60 defined by a depending portion 61 integral With the casting and including an upwardly extending tubular portion 62 surrounding the motor shaft. A flinger 65 in the form of an inverted cup member is secured on the shaft in the chamber 60 in overhanging relation with the portion 62 and acts to deflect any leaking liquid outwardly and to prevent it from access to the junction between the upper portion 62 and the shaft. A discharge tube 66 is threaded through the wall of part 61 and extends outwardly through an opening in the outer wall of casting 31 for direct drainage of any liquid which may accumulate in the bottom of the chamber 60. Y

The wash arm 70 is mounted for rotationabove and coaxially with the motor shaft 55 and is provided with multiple discharge slots 71. The Wash arm 70 includes a hollow hub 72 riding on a cylindrical bearing 73 which also connects the discharge end of the outlet passage 54 with the hollow hub and interior of the Wash arm. The wash arm is also supported by a bearing pin 75 pressfitted in the upper pump housing 41 and extending upwardly therefrom in coaxial relation with the impeller and the motor shaft 55.

The drain valve assembly includes a valve housing which is bolted at 81 on the front of the portion 35 of casting 31. A depending outlet portion 82 of housing 80 is adapted for direct connection to a suitable drain line (not shown). Within housing 80 is a tubular boss 83 which supports the stem 84 for the drain valve 85, which is a poppet type valve having an O-ring 86 or other suitable gasket arrangement to seat directly on the tapered valve seat 38 on the front end of the part 35 as previously described.

The valve stem 84 is reciprocated by a bell crank 90 pivoted at 91 in a fork 92 cast on the front of housing 80, the bell crank having a slotted connection 93 with the outer end of the valve stem 84. Operating movement of the bell crank is in turn controlled by a solenoid 95 having its plunger yieldably connected with the outer end of bell crank 90 by a spring 96 operating against a return spring 97 anchored to the cabinet. The solenoid 95 is energized and deenergized through the usual timer in proper relation with the washing and rinsing cycles to permit spring 97 to 1open the drain valve for discharge of the washing and rinsing liquids, reference being made in this connection to Geiger et al. Patent 2,707,961, issued VMay l0, 1955, to the assignee of the present application. l

The drain valve housing 80 also has a direct and continuously open connection with an overflow outlet assembly from the interior of the washing chamber to establish the maximum liquid level in the casing 20 during operation of the dishwasher. Referring to Figs. 2, 6 and 7, the overflow outlet includes a fitting 99 extending through the bottom of the casing 20 and provided With a slotted cap 100, the fitting 99 being held in position by a nut 101 and suitable gaskets as indicated in Fig. 6. The overflow drain line 102 is `secured to the lower end of fitting 99 by a clamp 103, and its other end is force fitted over laterally extending portion 105 of the Valve housing 80. As best shown in Fig. 2, the portion 105 is located on the downstream side of the drain valve 85 so that there is continuous communication therefrom through the interior of the valve housing 80 to its outlet portion 82.

A special strainer assembly is provided for preventing access of food particles to the inlets 45 of the pump housing 40. This assembly includes a main strainer which is provided with a central opening 111 for fitting closely around the upper end of the upper pump housing 41, and the periphery of strainer 110 includes a plurality of curved tabs 112 which seat on the correspondingly curved portion of the casing 20. The strainer 110 is provided with multiple relatively small-sized perforatious to provide a fine screen, satisfactory results having been obtained with these perforations of a diameter of 0.078

inch.

At the front of the strainer 110 there is a generally sector-shaped cutout which is defined by a depending flange 115 on strainer 110 and overlies the drain outlet 25. The space between the flange 115 and the adjacent por tion of the casing part 21 is filled by a second strainer unit which includesa tray portion 121 having relatively large perforations therethrough, namely, perforations of the order of Mi inch in diameter. The strainer unit 120 also includes a depending skirt portion 122 of fine screen material along its inner side which cooperates with the upwardly turned ange 123 on the part 121 to extend completely across the space between the wall 21 of casing 20 and the pump housing 40. A curved handle 12S at the front of strainer assembly 120 rests on the bottom of casing 20 and cooperates with the lower end of the skirt 122 to hold unit 120 in operative position with its upper surface spaced slightly below the main strainer section 110 for receiving food particles therefrom washed down thereon by the water running off the strainer 110. The handle 125 also facilitates removal of unit 120 by itself for dumping any food particles which may collect thereon.

In operation, the drain valve and the fill valve (not shown) are actuated in proper sequence by the timer in the usual manner to supply the proper amount of wash liquid to the sump 22. The motor 30 is also started by the timer, and it drives the impeller 50 to draw this wash liquid in through the inlet passages 45 and then to discharge it upwardly through passageways 52 into the wash arm for discharge against the disshes to be washed. This liquid then drains back downwardly into the sump for recirculation, and since the inlet passages 45 extend almost `completely around the pump housing at the bottom of the sump, the. water will tend to drain directly toward the center of the sump from all directions, thus .l creating an effective scouring action in the Sump which prevents possible deposit of soap scum and the like.

The downwardly draining water carries with it any food particles removed Vfrom the dishes, and such food particles ultimately reach the coarse screen 121 and thus pass downwardly therethrough but are prevented from reaching the pump inlets 45 by the skirt 122, s'o`that they settle into the space 36 as the washing cycle progresses. Then when the washing cycle ends and the drain valve is opened by the timer, all the food particles which have collected in the space 36 are flushed down the drain prior to the rinsing operation. During draining, the water in the main part of the sump will pass through the skirt 122 in the reverse direction from its course therethrough during recirculation and will therefore act to dislodge from the skirt any particles which may have lodged thereon and to carry such dislodged particles to the drain.

In addition to the practical advantages provided by the invention in the operation of the dishwasher, the construction of the invention has outstanding advantages from the standpoint of simplicity of removal of the parts for servicing. The strainer unit 120 is removable independently of the wash arm, and after the wash arm is lifted oif its support, the main strainer 110 may be lifted out of the washing chamber to expose the entire pump housing, which similarly can be removed by release of the mounting screws 42. If the motor requires servicing, it can then also be removed with ease by release of the mounting screws 33, after which the motor can be removed from the cabinet through the space provided by removal of the front cabinet panel below the door. Removal and servicing of the drain valve is similarly simple and convenient, requiring only release of the mounting screws 81 and disconnection of the valve housing from the overow drain line 102.

While the form of apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

1. A dishwasher of the character described comprising means including a casing defining a washing chamber having a sump adapted to be filled with liquid, a pump housing mounted centrally of they bottom of said sump and including a pumping chamber having an inlet open to said sump, a hollow wash arm mounted on the top of said pump housing for rotation on a substantially vertical axis and including a hollow hub, an impeller shaft mounted in said pump housing, means for driving said impeller shaft, an impeller mounted for rotation on said shaft in said pumping'chamber, means defining passageways in said pump housing arranged to conduct the liquid from said pumping chamber to said hollow hub for discharge from said wash arm into the interior of said washing chamber and drainage back into said sump, a drain outlet passageway depending from said sump at one side of said pump housing with the upper end thereof opening through the bottom wall of said sump, a drain valve controlling said passageway at a location spaced below said sump to provide space in said passageway for trapping food particles, a fine screen .adapted to cover the major portion of said sump and having a centrally located aperture therein for receiving said pump housing therethrough, means supporting said fine screen on the upper portion of said sump, the periphery of said iine screen being contoured to engage the side wall of said sump along a major portion thereof but to diverge therefrom along a minor portion thereof at a location providing a cut-out vertically overlying said passageway, a coarse screen proportioned for insertion in said cut-out in engagement with said sump side wall and said diverging portion of the periphery of said ne screen to block the passage through said cut-out of large food particles and leafy material while passing small food particles therethrough, a skirt of tine screen material depending from the portion of said coarse screen in engagement with said iine screen, and means supporting said coarse screen in said cut-out with said skirt in engagement with opposed side wall portions of said sump and with the bottom wall of said sump between said outlet passageway and said pump housing for cooperation with said sump wall portions to separate the space in said sump between said cut-out and said passageway from the remainder of said sump and thereby to prevent access to said pumping chamber inlet of food particles passing through said 4coarse screen and to effect the delivery of said small food particles to said trapping space in said outlet passageway.

2. A dishwasher of the character described comprising means including a casing delining a washing chamber having a sump adapted to be lilled With liquid, a pump housing associated with said casing and including a pumping chamber having an inlet open to said sump, wash spray means supported by said casing above said sump, means cooperating with said pump housing to conduct the liquid from said pumping chamber to said spray means for discharge into the interior of said washing chamber and drainage back into said sump, a drain outlet passageway depending from said sump at one side of said pump housing with the upper end thereof opening through the bottom wall of said sump, a drain valve controlling said passageway at a location spaced below said sump to provide space in said passageway for trapping food particles, a fine screen adapted to cover the major portion of said sump, means supporting said line screen on the upper portion of said sump, the periphery of said fine screen being contoured to engage the side wall of said sump along a major portion thereof ibut to diverge therefrom along a minor portion thereof at a location providing a cut-out vertically overlying passageway, a coarse screen proportioned for insertion in said cut-out in engagement with said sump side wall and said diverging portion of the periphery of said fine screen to block the passage through said cut-out of large food particles and leafy material while passing small food particles therethrough, a skirt of ine screen material depending from the portion of said .coarse screen in engagement with said first screen and proportioned to extend vertically from said tine screen to the bottom of said sump along the entire said diverging portion of the periphery of said line screen to separate the space in said sump between said cut-out and said passageway from the remainder of said sump and to prevent access of food particles from said separated space to said pumping chamber inlet, and means supporting said coarse screen in said cut-out with said skirt engaging the side and "bottom walls of said sump and with the upper surface of said coarse screen spaced slightly below said iine screen to promote passage therethrough of small food particles with said draining liquor for delivery to said trapping space in said outlet passageway.

3. A dishwasher as defined in claim 2 comprising a drain valve housing supporting said drain valve outside said sump and including an outlet portion on the downstream side of said valve from said outlet passageway,

-means defining an overow outlet through said casing at a location spaced upwardly and outwardly from said fine screen, and lan overflow drain line located outside said sump and connecting said overflow outlet directly with said outlet portion of said valve housing.

References Cited in the lile of this patent UNITED STATES PATENTS 1,597,361 Hazard Aug. 24, 1926 1,637,376 Gibney Aug. 2, 1927 2,287,628 McMahan June 23, 1942 2,573,067 Sandberg oct. 3o, 1951 2,681,658 Meeker June 22, 1954 UNITED STATES PATENT OFFICE CERTIFICATE 0F CORRECTION etent No, 2,862,5l0 December 2y 1958 Russell C Geiger `et al ars in the printed specification It is hereby certified that error appe ecton and that the said Letters of the above numbered patent requiring corr `Patent should read as corrected below.

Column 4, line 59, for "dsehe'e" read me dishes me; Column 6g line 38g Tor "first screenu read mf finev screen fm.,

Signed end sealed this 14th dey of April M9590 SEAL t'test) KARL H., AXLNE Attesting Ocer ROBERT C. WATSON Commissioner of Patents