US2657095A

US2657095A - Impeller assembly for dishwashers

Info

Publication number: US2657095A
Application number: US166804A
Authority: US
Inventors: Lewis A James; Duane A James
Original assignee: Individual
Current assignee: Individual
Priority date: 1950-06-08
Filing date: 1950-06-08
Publication date: 1953-10-27
Anticipated expiration: 1970-10-27

Description

Oct. 27, 1953 L, JAMES ET AL 2,657,095

IMPELLER ASSEMBLY FOR DISHWASHERS Filed June 8, 1950 2 Sheets-Sheet l 65 3m nentors lW/IS 4411727615, and 8 04/0/76 4. James W i W Oct. 27, 1953 L. A. JAMES ET AL 2,657,095

IMPELLER ASSEMBLY FOR DISHWASHERS Filed June 8, 1950 2 Sheets-Sheet .2

2 L V1 V 1 7 3 1/5 A. 1/0/7295, and J4 60 3 Duo/7e A /ames (Ittomegs Patented Oct. 27, 1953 2,657,095 IMPELIJER ASSEMBLY FOR DISHWASHERS LBWiSfA. James (and Duane A. Independence, Kans.

J ames,

Application June 8, 1950, Serial No. 166,804

12 Claims; 1

invention relates to 'dishw'ash'ing'machines andimpeller assemblies therefor and more particularly to a dishwashenimpeller assembly ineluding a self-cleaning'filter and a rotary' or oseillatingballie against which washing liquid is dirEctedWith' considerable Velocity for distribution in a sweepingmoveinent'over articles to be The objects of the present invention are to providea'dishwasher having an unitary impeller assembly in the washing compartment for moving liduid'from the bottoihof the compartment and delivering said liquid against a moving baflle at considerable velocity for deflection onto articles t'o bewashed; to provide a filter screen on the impeller unit for removing food particles and the like from liquid drawn into the impeller unit; to provide an impeller housing and related structure for directing delivery of liquid whereby a portion thereof automatically cleans the parades from the screen and prevents clogging thereof; to provide related curvatures in the impllr baffle for effecting a sweeping action of the liquid over articles to be washed and minii'nizi'n'g noise andvibration of operation; to prot 'i'de automatic apparatus for stopping delivery of liquid from the impeller when the level of liquid in the washing compartment is low and thereby reducing collection of mist or droplets on the Washed "articles as the liquid is being drained "from said "washing compartment; and

to provide a dishwashing machine and impeller "as's'efnbl'y'th'refor which are economical to manufacture and "efficient in operation for washing and rinsing "dishes and the like and reducing the formation oi-uroplets thereon.

In accomplishing these and other objects of the present invention, we-have: provided" improved details or structure, the preferred forms of which are illustrated in "the accompanying "drawings,

wherein:

Fig. =1 is a perspectiv view 'of a dishwasher impeller assembly with portions broken away to better illustrate the structure thereof.

Fig. 2 is aside elevation of the impeller assembly with portions broken away at theendsthereof to better illustratethe mounting of the impeller} bailleand baflle drive.

Fig. 3 is 'a transverse sectional view through a1 portion of a dishwasher with theimpeller assembly mounted therein.

Fig. "e-is anendelevation ofthe impeller asthe impeller assembly with th liquid delivery from the impeller closed.

Referring more in detail to the drawings:

I designates a portion of a dishwashing machine having a washing compartment 2 formed by side walls 3, end walls 4, bottom wall 5 and a coverinot shown). Th bottom 5 is preferably cylindrical with the axis thereof longitudinally of the washing compartment, whereby said bottom forms a sump for liquid 6-. A drain I has communication as at 8 with the washin compartment andis controlled by a suitable valve 9 for selectively draining wash or rinse liquid from the washing compartment.

An impeller assembly I0 is mounted in the washing compartment and suitably drive n to deliver washing and/or rinse liquid at considerable velocity onto articles H to be washed which are preferably supported on a suitable rack I 2 arranged in the 'washingcompartment and supported on the walls thereof. The impeller assembly Ill preferably is so constructed {to form a unit adapted to be mounted in the washing compartment -2 and extend longitudinally thereof, said impeller assembly being substantially coextensive with the washing compartment with gaskets l3 and I4 between the ends of the impeller unit and the end walls 4 of the washing compartment. The impeller unit In generally consists of an impeller l-5 rotatably-mounted in a housing lfisand arranged to deliver washing orrinsing liquid at considerable velocity-through a longitudinal .openingor slot I! in said housing and directing said liquid against a movably mounted baffle it which deflects the liquid inra sheet which sweeps over and impingesagainst articles to be washed. The housing 16- is provided with end members I 9 and 20 having inwardlyextending bearing'bosses 2| and 22 provided with bores Hand 24 respectively-for rotatabl-ymountingthe ends of the impeller shafts-25. The end members [9 and 20-are also provided with inwardly extending flanges .26 and Z'lsubstantially coaxial with thebores 23 and 24.

A substantially cylindrical shell 28, preferably formed of thin'sheet metal is suitably secured to and supported by the endmembers I 9 and 251. The 'ends of the shell 28 are preferably sleevedoverthe flanges 26 and 21 and secured theretor-byfastening devices such asscrews "29. 'Thelshell 28is provided with an opening 30 for :entrance of liquid into'theimpeller housing. The opening 30 preferably extends longitudinally of the housing and is substantially diametrically asoppositevtheslot l1. A-filter.=3I of fine mesh wire screen covers the opening and is suitably secured to the shell 28 at the

side edges

32 and 33 of the opening 33 whereby all liquid entering the impeller housing must pass through the filter 3| said screen being at an angle to the periphery of the shell 28 for facilitating cleaning, as later described.

The impeller i5 consists of a blade 34 preferably formed of a single sheet of metal suitably secured to the impeller shaft 25. In the structure illustrated, the blade 34 is provided with a plurality of longitudinally spaced cuts extending across the axis and perpendicular thereto and alternate portions of the blade defined by the cuts pressed laterally to form a bore 35 whereby the impeller may be sleeved on the shaft 25 and the alternate portions defined by the cuts arranged on opposite sides of said shaft, the impeller being located on the shaft between the bearing bosses 2| and 22 and suitably secured to said shaft as by welding or the like whereby said impeller blade will rotate with the shaft. The blade 34 has oppositely directed portions which terminate in

side edges

36 and 36 slightly spaced from the inner surface of the shell 28 to provide clearance therebetween. It is preferable that the outer portions 31 of the blade be bent toward the direction of rotation of the impeller, and that the blade have a longitudinal twist or spiral of 180 to substantially equalize the force exerted between the blades and the liquid throughout the length of the impeller.

As illustrated in Fig. 3, the impeller unit is so arranged that when mounted in the washing compartment of the dishwasher the opening 33 in the shell 28 is positioned adjacent the bottom 5 and the slot I! which extends longitudinally of the impeller and is substantially coextensive therewith is positioned whereby liquid moved by the impeller will be directed through the slot ll substantially tangentially of the blade portion 3'! and vertically at approximately the longitudinal center of the washing compartment.

The end members l9 and 20 have portions 40 and 4| extending upwardly and laterally of the axis of the impeller and have bearing

bosses

42 and 43 provided with

aligned bores

44 and 45 rotatably mounting

trunnions

46 and 41 which are fixed to the ends of the baffle l8, whereby the bafile rotates on an axis substantially parallel with the axis of the impeller shaft and in alignment with the stream of washing liquid delivered by the impeller through the slot H. The bafile l6 preferably consists of a thin, fiat, elongated strip of metal of such length that the ends extend beyond the ends of the slot H, the side edges 46 of said baffie having clearance with the shell 28. The bafile I8 is preferably provided with a longitudinal twist or spiral of substantially 180, the direction of the spiral being opposite to the direction of the spiral of the impeller blade 34.

The end member H! is preferably provided with an outwardly extending peripheral flange 49 and mounted on said flange is a plate 50 which cooperates with the end member to enclose a drive which rotates the baffle IS, the plate 50 being provided with bores 5| and 52 through which extend the impeller shaft 25 and trunnion 46 respectively. Suitable seal rings 53 and 54 are provided in the bore 5| and bore 23 to retain any necessary lubricants in the baflle drive. It is preferable that the baiiie rotate at a much slower speed than the impeller and in the same direction, and while various driving mechanisms may be used in the illustrated form the outer end of the shaft 25 extends beyond the bore 5| and is adapted to be suitably connected and driven by a prime mover for rotating the shaft 25, An eccentric 55 is fixed to the shaft 25 between the end member l9 and the plate 50 and rotatably mounted on the eccentric is a strap 56 having a detent 51 extending therefrom. The strap is shown as consisting of two

arcuate members

58 and 59 engaging around the eccentric and held thereon by a spring 55 extending around the peripheries of said arcuate members. The spring effects resilient engagement of the arcuate members with the eccentric whereby rotation of said eccentric holds the end of the detent in engagement with the teeth 6| of a ratchet wheel 62 fixed on the trunnion 46. Rotation of the eccentric 55 moves the detent to turn the ratchet wheel by increments, said ratchet wheel being held against backward movement by means of a spring pawl 63 suitably secured to the end member I9 and having its end engaging in teeth 6| of said ratchet wheel.

It is preferable that screws or the like 64 retain the plate 56 on the end member l9 and that the shanks of said screws extend outwardly through suitable openings in the end wall 4 of the washing compartment for mounting the impelier unit in said compartment in the position shown in Fig. 3. With the impeller unit arranged in this manner in the washing compartment a pipe 65 connected to a suitable source of Washing and rinse liquid, for example a hot water tank in the water system of a house, extends through the bottom 5 of the washing compartment and into the impeller housing adjacent the end member 20. A nozzle fitting 66 is mounted on the pipe 65 and so arranged as to direct liquid into the impeller housing in a jet substantially parallel to the axis of the shaft 25.

The prime mover (not shown) is operated to drive the impeller [5 during the admission of liquid to the impeller housing and throws liquid upwardly around the interior of the shell l6 and delivers said liquid in a relatively flat stream or jet through the slot l1, substantially tangentially to the arc of rotation of the impeller blade portion 31. As the impeller is rotated, the eccentric 55 is also rotated to move the detent 51, thereby rotating the ratchet wheel 62 by increments. A stream of water discharged by the impeller through the slot I! strikes the side surfaces of the baffle l8 and is deflected thereby in fiat, thin sheets or jets having considerable velocity to impinge on the articles to be washed. As the baffle is rotated, it presents a gradual changing angularity of the side faces relative to the stream of water delivered by the impeller, and this gradual changing surface deflects the stream of water in a sheet which sweeps the entire washing compartment.

When sufficient liquid is admitted to the washing compartment the supply is turned off and operation of the impeller unit continued for a considerable period of time to thoroughly wash the articles, the wash liquid being drawn into the impeller housing through the filter 3| and delivered through the slot ll. Movement of the liquid through the filter 3| tends to carry food particles and the like and deposit same on the screen filter, and if said particles are not removed said filter would soon be clogged. Due to the particular location of the opening 3!! and filter therein and the slot ll, a portion of the liquid moved by the impeller is carried around inside of memories the shellsllezandtthrowmagainst thesinsldenot'the screen filter: 3.1 .-passingzthrough.sameuandxcarrw ingsofl thescollectedizfood particles. Thisraction istfacilitated having": the; screen". i 3 .1 arranged at" an slight 1 angle vto"thetperipherv'otfthe: shell. with: the: lowerr portiom of their screen. having greater; spacingr from; these impeller blades: than the upper portions-1 as: illustratedtin Also the filter cleaning; action repeats itself; on each revolution ofthezimpeller: Floodxiparticlescthereby are: washed? front: their screen; and: settle; tow the bottom :.of the: washing-"compartmentwhererthey remaimduring;the-balancevofilthe'washingiaction.

After the: articles are washed for'ar suitable period-bi? time the valve: 9 is actuated to drain thev liquidrfromtthe washingicompartment: After draining; ther wash liquidi from: the washing compartmenm rinsea liquid is: supplied through the nozzlerfittingt 66s: ands. the" impeller: unit? operat'edito :throw the rinsevliquidlthrongh the slot l'l and di'recti same against theside; :faces of 'the battle I8; whichdeflects 'the'rinse liquidfin'a sheet sweepingtheentirewashingscompartmentz After rinsing" the articles-= the valve 9 is: again on eratedl'to drain 'the'rinse waterf'rom thewashing compartment;

It 1 has: been found that as: lthel liquidiis: drained from. the" washing: compartment the liquid delivered by the impeller. gradually decreases in quantity" and finallybecomes a fine mist which is deposited in droplets: on the articles inthe washing compartment? Whenthe droplets: dry there' are small spots on the articles; To eliminate=tl iis=-condi 'tiona: valve in the form ofa'flat vane t l is hingediy mounted "as: at Ga on the shell '1 28 at the side of "the slot-ll; said valvebeing of such sizetha-t when the "freeend thereof isswung toward" the=shell 28it e1rgages the upper'side edge orthe sl'ot I l and substantiallyclosessameto out off delivery I oflicluid" through the" slot" I T; The valve is" provided with an' ear-twwhich-is pivotalconnected to'oner end of a link 1 0, the'other end of said link being pivotal-Hy connected as: at" H to'a float lever12 whicli is pivotallymounted; as at T3; on an can 1'4 mounted on and-extending laterally of-"the shellr nl A fioahmemb'er' I5-'T'is mounted on'tl'ielever l2 whereby wh'en the level of liquid raises-in the washihg'chamber the fioat swings the lever 12 exerting force on -tlie'linlt 1 0 to sw-ing thevalve 61 to -open position which is substantiallyvertical-1y; whereby said valve-forms an extension of th e" shell and ism substantially tangentlal"thereto. In open position the valve engages a log Hi on the-end member l9 which servesas a limit to thee opening of the valve. When the: liquid Flowers-in the washing compel-t:- ment, as: when it"isbeingrdrained; to a; mode termined: =1'vel .iatwhizch :thel impellenwill' 'tend' to deliver? mist" insteadrof'a: stream? of 'liquid; the float movesr. downwardly with" thedevel: oi? liquid and; swings: the valve-stat closed positionpshuttin'g air the delivery of; the-mist from? the: impeller, thereby permitting thewet articlesin; the 'wa-sh ingzcompartmentto drain andndry normally; with substantially no: liquid spots-1 thereon.

The? relatedispirals -ofi the: impeller: bladezand ba-file and the relativemfast. rotation of' the pel-ler anmslow: rotationofithe bafiie direct the liquid delivered lb'y" the: impelierins the? form" of a? jet that moves longitudinally" of z the: washing compartment "and lat diil'erent'fanglesi determined by" the: spiral ofj the: baflie; .and: rotation: of" the bailie causes: the: jetiatowsweep transverse-11y: otiithe washing: compartment, Therefore the: jet;. in cit feet; moves back; amdxfortluand; simultaneously advances-,ztransversely of. the: washing: compartment.:to completely. sweep the entireinteriozro! said. washing compartment Also the; spiral arr-'- rangement; of. theimpeller bladetenda to: equalize the. "force between. the. blade and l the liquidaxbeing moved; reducing vibration. andinoise in the opera:- tion of the unit.

Itais: believed, obvious that wehave providedla dishwasher and impeller unit: thereforwhich; is economical to manufactureand: efiicient in: operrationiofi delivering-a powerfulstream; of. liquid against articles to be washed with a; self-cleaning filter for preventingareturningJof food particles to the articles; said unit eliminating delivery of mistz-tozthe articles; and thereby facilitating; drying; withoutliquid spots thereon.

What we claim and desire to secure byLetters Patentzis:

1:.. An" impeller unit for? dishwashing machines comprising; an elongated housing adapted" to;.be usedrinfixe'd horizontal position with the lower portion below the level of liquid used in washing dishes, said housing: having openings substan=- tially oppositely arranged therein, one of? said openingsbeing in thealower portion of the.hous ing and forming a; liquid inlet andithe other'a liquid discharge opening; an impeller-shaft rotat a'bly-mounted in the housingandfextending longitudinally thereof; impeller blades fixed; on; the impeller shaft? and extending longitudinally thereof for; discharging liquid through the dis:- charge opening of the housing in response: to rotation 'of' the impeller'shaft, an. elongated bafile spaced above and: aligned" with the" discharge opening: of the housing and? movably' mounted thereon whereby liquid: discharged through said openin is directediin a stream against-the bafile, and means formovingthe bafiieifor deflecting the stream of liquidand= providing: a. sweeping ac tion thereto:

2. An: impeller: unit for dishwashingmachines comprising, an elongated housingadapted to be used in fixedwhorizontal position with the lower portion below: the: level of liquidused in washing dishes, said housingihaving'isubstantially oppo sl-tewopeningsi extending. longitudinally thereof, onerof'saidjopeningsbeing'in the lower portion of the housing and forming aaliquid inlet. and theJother arliquiddischargeropening, an impeller shaft lIOtQtflblYIl'lOllIltfidgiIlthef hollsillg; impeller bladesfixedon-"the impeller shaft and extending longitudinally thereof for discharging liquid through the:dischargeopening of the housing in response to rotation of: theimpeller shaft; an elongated baffie substantially? coextensive: with the impeller blades and parallel thereto, .means on the: housing-:mormting the baiile "for rotation aboutlan axis-spaced abovea'and aligned with the dischargeopeningrof; therhousing whereby liquid discharged, through; said opening; is directed in astream aigainstl-the :baiile, andv means tforrmovin'g therhaflle': for defiecting the "stream of liquid and providinga sweepingaction thereto.

3.. An impeller unit for: dishwashin wmachines comprising; an: elongated substantially cylindrical housing adapted .to& be used'in fixed horizontal position with the lower portion below the level of liqui-dl-usedrin washing dishes; said housing having substantially. diametrically 'oppositeaopenings extending: longitudinally thereof,. one of said openings being-in the lower portion of the housingi andwforming a; liquid: inlet the other: a liquid" discharge opening; an"; impeller shafti rotatablyi mountedxin the housing:substantially on the longitudinal; axis: thereof? impeller blades fixed on the impeller shaft and extending longitudinally thereof for discharging liquid through the discharge opening of the housing in response to rotation of the impeller shaft, said blades being in the form of a spiral about said shaft, an

elongated baffle substantially coextensive with the cal housing adapted to be used in fixed horizontal position with the lower portion below the level of liquid used in washing dishes, said housing having substantially diametrically opposite openings extending longitudinally thereof, one of said openings being in the lower portion of the hous ing and forming a liquid inlet and the other a liquid discharge opening, an impeller shaft rotatably mounted in the housing substantially on the longitudinal axis thereof, impeller blades fixed on the impeller shaft and extending longitudinally thereof for discharging liquid through the discharge opening of the housing in response to rotation of the impeller shaft, an elongated bafiie spaced above and aligned with the discharge opening of the housing and movably mounted thereon whereby liquid discharged through said opening substantially tangentially f the housing is directed in a stream against the baffle, means for moving the baffle for deflecting the stream of liquid and providing a sweeping action thereto, a valve on the housing for opening and closin the discharge opening thereof, and means responsive to the level of liquid around the exterior of the housing for operating said valve closing the discharge opening in the housing when the level of liquid relative to the inlet opening is inadequate to supply a suitable quantity of liquid to the impeller.

5. An impeller unit for dishwashing machines comprising, an elongated substantially cylindrical housing adapted to be used in fixed horizontal position with the lower portion below the level of liquid used in washing dishes, said housing having substantially diametrically opposite openings extending longitudinally thereof, one of said openings being in'the lower portion of the housing and forming a liquid inlet and the other a liquid discharge opening, an impeller shaft rotatably mounted in the housing substantially on the longitudinal axis thereof, impeller blades fixed on the impeller shaft and extending longitudinally thereof for discharging liquid through the discharge opening of the housing in response to rotation of the impeller shaft, said blades being in the form of a spiral about said shaft, an elongated baffle substantially coextensive with the impeller blade and parallel thereto, means on the housing mounting the baffle for rotation about an axis spaced above and aligned with the discharge opening of the housing whereby liquid discharged through said opening substantially tangentially of the housing is directed in a stream against the baffle, mean for rotating the baffle for deflecting the stream of liquid and providing a sweeping action thereto, and a filter screen covering the liquid inlet opening of the housing, said screen being at an angle to the periphery of the housing with the lower portion of said screen having the greater spacing from the impeller blades whereby a portion of liquid not discharged through the discharge opening is carried around in the housing by the impeller and directed across and through the screen for cleaning any material therefrom.

6. An impeller unit for dishwashing machines comprising, an elongated substantially cylindrical housing adapted to be used in a fixed horizontal position with the lower portion below the level of liquid used for washing dishes, said housing having substantially diametrically opposite openings extending longitudinally thereof, one of said openings being in the lower portion of the housing and forming a liquid inlet'and the other a liquid discharge opening, an impeller shaft rotatably mounted in the housing substantially on the longitudinal axis thereof, impeller blades fixed on the impeller shaft and extending longitudinally thereof for discharging liquid through the discharge opening of the housing in response to rotation of the impeller shaft, an elongated baflle substantially coextensive with th impeller blades and parallel thereto, means on the housing mounting the baffle for rotation about an axis spaced above and aligned with the discharge opening of the housing whereby liquid discharged through said opening substantially tangentially of the housing is directed in a stream against the baflie, means for moving the baffle for deflecting the stream of liquid and providing a sweeping action thereto, a filter screen covering the liquid inlet opening of -the housing, said screen being at an angle to the periphery of the housing whereby movement of liquid in the housing in response to rotation of the impeller discharges a portion of said liquid from the housing through the screen for cleaning any material therefrom, a valve hingedly mounted on the housing for opening and closing the discharge opening thereof, and means responsive to level of liquid around the exterior of the housing for operating said valve closing same when the level of liquid relative to the inlet opening is inadequate to supply a suitable quantity of liquid to the impeller.

'7. An impeller unit for dishwashing machines comprising, an elongated substantially cylindrical housing adatped to be used in fixed horizontal position with the lower portion below the level of liquid used in washing dishes, said housing having substantially diametrically opposite openings extending longitudinally thereof, one of said openings being in the lower portion of the housing and forming a liquid inlet and the other a liquid discharge opening, an impeller shaft rotatably mounted in the housing substantially on the longitudinal axis thereof, impeller blades fixed on the impeller shaft and extending longitudinally thereof for discharging liquid through the discharge opening of the housing in response to rotation of the impeller shaft, an elongated baffie substantially coextensive with the impeller blades and parallel thereto, means on the housing mounting the baffle for rotation about an axis spaced above and aligned with the discharge opening of the housing whereby liquid discharged through said opening substantially tangentially of the housing is directed in a stream against the baflie, an eccentric fixed to the impeller shaft, a ratchet wheel fixed to the baffle, and a pawl operated by the eccentric and engaging the ratchet wheel ridrimmed gi'n response td rotation I the impeller for rotating me ane; by "mere" ments for deflecting the stream of liquid and having substantially diametricallyopposite open ingsj extending longitudinally thereof, one 'f'said A,

openings being in the" lower portion of the hous; ingflmd form n "a liq'iiid'inl'et'. and the oth'e a liquid dischargeopening, anjimpeller shaft'r tatably mounted in thehou'sing substantiallyion thef oligituclinal axis thereqr impeller blades; fixed on the im ener shaft and extending 1origi-" tudinally thereof for discharging liquid through the discharge opening of the housing in response to rotation of the impeller shaft, said blades being in the form of a spiral about said shaft, an elongated baille substantially coextensive with the impeller blades and parallel thereto, means on the housing mounting the baffle for rotation about an axis spaced above and aligned with the discharge opening of the housing whereby liquid discharged through said opening substantially tangentially of the housing is directed in a stream against the baffle, an eccentric fixed to the impeller shaft, a ratchet wheel fixed to the baffle, a pawl operated by the eccentric and engaging the ratchet whee1 and operated in response to rotation of the impeller for rotating the bafile by increments for deflecting the stream of liquid and providing a sweeping action thereto, a filter screen covering the liquid inlet opening of the housing, said screen being at an angle to the periphery of the housing whereby movement of liquid in the housing in response to rotation of the impeller discharges a portion of said liquid from the housing through the screen for cleaning any material therefrom, a valve hingedly mounted on the housing for opening and closing the discharge opening thereof, and means responsive to level of liquid around the exterior of the housing for operating said valve closing same when the level of liquid relative to the inlet opening is inadequate to supply a suitable quantity of liquid to the impeller.

9. An impeller unit for dishwashing machines comprising, an elongated housing adapted to be used in a fixed horizontal position with the lower portion below the level of liquid used in washing dishes, said housing having openings substantially oppositely arranged therein, one of said openings being in the lower portion of the housing and forming a liquid inlet and the other a liquid discharge opening, an impeller shaft rotatably mounted on the housing and extending longitudinally thereof, impeller blades fixed on the impeller shaft and extending longitudinally thereof for discharging liquid through the discharge opening of the housing in response to rotation of the impeller shaft, and a filter screen covering the liquid inlet opening of the housing, said screen being substantially tangential with the periphery of the housing adjacent the upper portion of the inlet opening and having greater spacing from the impeller blade at the lower portion of the inlet opening whereby a portion of the liquid not discharged through the discharge opening is carried around in the housing by the impeller and directed across through the screen for dislodging any material adhering to the exterior thereof.

10. itinaimpell'erunit for dishwasing machines comprising, an elongated substantially cylindricalhoii's'ifig adapted'to be used in fixed horizontal positio withgtheolower*portion below the level of liquid usedin washingdishes, said housing having substantially diametrically opposite openingsjfextending longitudinally :thereof, one of said openings being inthe lower portionof the housing and-forming aliquid inlet and theother a liquid discharge opening,tmrim p'eller shaft ma tatably mountediin the' housing. substantially on i the longitudirial axiswthereof, impeller blades fixedon th'e timpeller, shaft "extending longitu-a dinallyi 'threof for i discharging 1 liquid through i the dis'charge'opening of the housing in response to rotation of =the impellershaft, said bladesbeing in' thei form fofi'a spiral about said 'shaft an elongated baiiie substantially coextensive'withthe impeller blades and parallel thereto, said baffle being on a spiral reversely to the spiral of the impeller blades, means on the housing mounting the baffle for rotation about an axis spaced above and aligned with the discharge opening of the housing whereby liquid discharged through said opening substantially tangentially of the housing is directed in a stream against the baflie, means for rotating the baffle for deflecting the stream of liquid and providing a sweeping action thereto, a valve on the housing for opening and closing the discharge opening thereof, and means responsive to the level of liquid around the exterior of the housing for operating said valve closing the discharge opening in the housing when the level of liquid relative to the inlet opening is inadequate to supply a suitable quantity of liquid to the impeller.

11. An impeller unit for dishwashing machines comprising, an elongated substantially cylindrical housing adapted to be used in fixed horizontal position with the lower portion below the level of liquid used in washing dishes, said housing having substantially diametrically opposite openings extending longitudinally thereof, one of said openings being in the lower portion of the housing and forming a liquid inlet and the other a liquid discharge opening, an impeller shaft rotatably mounted in the housing substantially on the longitudinal axis thereof, impeller blades fixed on the impeller shaft extending longitudinally thereof for discharging liquid through the discharge opening of the housing in response to rotation of the impeller shaft, said blades being in the form of a spiral about said shaft, an elongated baflle substantially coextensive with the impeller blades and parallel thereto, said baflle being on a spiral reversely to the spiral of the impeller blades, means on the housing mounting the baffle for rotation about an axis spaced above and aligned with the discharge opening of the housing whereby liquid discharged through said opening substantially tangentially of the housing is directed in a stream against the baflie, means for rotating the bailie for deflecting the stream of liquid and providing a sweeping action thereto, a flat valve hingedly mounted on the housing at one side of the discharge opening thereof for opening and closing said discharge opening, stop means for limiting opening of the valve whereby said valve forms a tangential extension of the housing and extends toward the baffle, and means responsive to the level of liquid around the exterior of the housing for operating said valve closing the discharge opening in the housing when the level of liquid relative to the inlet opening is inade- 11 quate to supply a suitable quantity of liquid to the impeller.

12. An impeller unit for dishwashing machines comprising, anelongated housing adapted to be used in fixed horizontal position with the lower portion below the level of liquid used in washing dishes, said housing having a liquid inlet opening in the lower portion thereof and a liquid discharge opening in the portion above the level of liquid used in washing dishes, means in the housing for discharging liquid through the discharge opening, an elongated baffle spaced above and aligned with the discharge opening of the housing, said baffle being spiraled longitudinally thereof, means mounting the baflle for rotation about an axis spaced above and aligned with the discharge opening whereby liquid discharged through said opening is directed against the baflle, and means for rotating the baflle for defleeting the stream of liquid and providing a sweeping action thereto.

Number Name Date 553,677 Hoyt Jan. 28, 1896 1,469,207 Blakeslee Oct. 2, 1923 2,237,209 Arnold Apr. 1, 1941 2,257,929 Yochem Oct. 7, 1941 2,257,930 Yochem Oct. 7, 1941 2,274,024 Yochem Feb. 24, 1942 2,317,014 Yochem Apr. 20, 1943