US3129711A - Dishwasher recirculating assembly - Google Patents

Description

April 21, 1964 2 Sheets-Sheet 1 Original Filed Sept. 29, 1960 FIG. I

N v R mm VF m. w m C S Y 3 W 3J 5 3 ATTORNEYS April 21, 1964 J. G. SCHMITT- DISHWASHER acmcuuvrmc ASSEMBLY Original Filed Sept 29, 1960 MATZEN 2 Sheets-Sheet 2 FIG. 2

FIG. 5

l 39 as a FIG. 6

INVENTOR.

ATTORNEYS United States Patent 3,129,711 DEHWASHER RECIRQULATING ASSEMBLY Jehn G. Schmitt-Matzen, Bellville, Ohio, assignor to German-limp Industries, 1nd,, Bellviile, Ohio, a corporation of Ghio Original application Sept. 29, 1969, Ser. No. 59,295, new Patent No. 3,163,225, dated Sept. 10, 1963. Divided and this application May 1, 1963, Ser. No. 280,186

8 Clm'ms. (Cl. 13456) The present invention relates generally to washwater circulating systems for automatic dishwasher assemblies and, more particularly, an automatic dishwasher assembly which recirculates the washwater, mechanically macerates food particles, strains the recirculating water and selfcleans the strainer. This application is a division of application Serial No. 59,295, filed September 29, 1960', now Patent No. 3,103,225.

Although the time and labor saving automatic dishwashers found in most modern kitchens provide an adequate mechanical substitute for manually washing and drying the dishes, the dishes must be scraped and rinsed before they are put in the washers. This pre-removal of the food particles is particularly required when the dishwasher is the type employing a spray discharge to impinge the washwater on the dishes, because the food particles would otherwise clog the jets as the washwater is circulated. Even the type of dishwashers which use an impeller for throwing the water against the dishes requires a pre-removal of the food particles to prevent clogging of the drain.

It is, therefore, the primary object of the present invention to provide an automatic dishwasher assembly having a circulating system which allows placing dishes in the dishwasher without first scraping and rinsing off the food particles, even when the dishwasher is the type employing a spray discharge to impinge water against the dishes.

It is a further object of the present invention to provide a dishwasher assembly having a circulating system which requires only one pump for recirculating the water during the washing or rinsing cycles and for pumping out the waste water during the drain cycles.

It is a still further object of the present invention to provide a dishwasher assembly having a circulating system in which an automatic screening mechanism selectively strains the washwater while it is being circulated through the spray jets, and which cleans itself during the drain cycle.

It is a still further object of the present invention to provide a dishwasher assembly having a circulating system in which any food particles carried in the water passing through the pump are mechanically macerated.

These and other objects which will become apparent from the following specification are accomplished by the novel and improved means hereinafter described and claimed.

A preferred embodiment is shown by way of example in the accompanying drawings and hereinafter described in detail without attempting to show all the various forms and modifications in 'which the invention might be embodied; the invention being measured by the appended claims and not by the details of the specification.

In the present invention a single pump drains the water out of the dishwasher and discharges it through a Volute passage in communication with the spray jets which impinge the water upon the dish%. A grille, or coarse mesh screen, is positioned in advance of the pump inlet to prevent silverware or other material, which would be deleterious to the pump or macerating ring, from being drawn into the pump. A fine mesh screen is positioned between the grille and the pump to prevent food particles above a certain size from being drawn into the pump while the washwater is being circulated. This screen is preferably of such a gauge that particles normally passing therethrough will not clog the jets.

A solenoid-operated flap valve is positioned selectively to direct the flow of Washwa-ter through the volute passage to the spray jets or drain in timed sequence. Hydraulic pressure in the passageway between the flap valve and the spray jets operates a mechanism which selectively controls the flow either through the fine mesh screen to filter the circulating water or across the screen to clean it during the drain cycle.

The food particles washed from the screen during the drain cycle are reduced in size by a macerating ring so that they can be safely discharged with the waste water into a domestic sanitary system without clogging the pipes.

Referring to the drawings:

FIG. 1 is a partial top plan view of a dishwasher according to the present invention;

FIG. 2 is a partial cross section taken substantially along line 2-2 of FIG. 1;

FIG. 3 is a horizontal section taken substantially on line 3-3 of FIG. 2 showing the interior of the circulating pump in plan;

FIG. 4 is an enlarged fragmentary area of FIG. 3 showing the macerating ring in cross section;

FIG. 5 is a cross section taken substantially online 55 of FIG. 2; and

'FIG. 6 is a perspective View of the macerating ring used in the present invention and also showing generally how it circumscribes the pump impeller unit.

Referring now to FIGS. 1 and 2, a dishwasher, identified generally by the numeral v10, includes a cabinet section 11 adapted to receive a dish basket (not shown). Asump section 12 is disposed beneath cabinet 11 and communicates with theinlet 13 of a pump .14 throughpassage 15 in the lowest portion ofsump 12.

Ashouldered recess 16 is preferably provided at the juncture of cabinet '11 andsump 12. A grille, or large mesh screen, 18 secured toframe 19 is removably seated inrecess 16 to prevent utensils or excessively large bones or food particles from inadvertently entering pump \14.

Spaced vertically beneath grille 1 8 is adeflection plate 20. Aflange 21 extends along the three sides ofplate 20 adjacent the side walls of sump 1'2 and is secured thereto by welding or other means not shown. The fourth side ofplate 20 is secured at spacedportions 20 to ahinge pin 22, the terminal ends of which are in turn secured to the side walls ofsump 12.Plate 20 is preferably inclined downwardly towardpin 22 to provide a convergent channel toward a finemesh gate screen 23 which is selectively positionable transversely across the flow path throughsump 12.Gate screen 23 is swingably mounted onpin 22, as by a plurality of flaps .24 which rotatably engagepin 22 between portions 20' ofplate 20.

An actuatingarm 25 may be attached to, or be an extension of, aflap 24 topivot gate screen 23 in response to the displacement of anactuating rod 26, as will be more fully hereinafter described.Rod 26 is preferably connected to the dishedend 28 ofarm 25, as by apin 29.

Thehousing 30 andhousing cover plate 31 ofpump 14 may be attached beneathsump 12, as by a plurality ofbolts 32 threaded intohousing 30. Amotor 33 is adapted to provide the motive power required to rotate theimpeller unit 34 withinpump cavity 35, as by nou rotatably connectingmotor shaft 36 to theunit 34. Referring also to FIGS. 3 and 6, circumferentially spacedimpeller blades 37 extend angularly outwardly from and are attached to thehub 38. Further rigidity is preferably imparted toblades 37 by also securing them tobase plate 39. Of course,blades 37,hub 38 andbase plate 39 may be integrally formed.

An annular macerating ring, or cutting ring difluser 40 encircles the radially outermost ends ofblades 37 and is fixedly received in opposedannular grooves 41 and 42 in thehousing 30 andhousing cover plate 31, respectively. The grater-likemacerating ring 48, as best shown in FIG. 4, is perforated bymultitudinous apertures 43. A portion of thering 46 adjacent eachaperture 43 is inwardly depressed to present an offset cutting or gratingedge 44 in opposition to the direction of rotation ofblades 37. Outwardly of ring 44) thepump cavity 35 comprises avolute passage 45 which spirals outwardly intohousing 30 as adivergent discharge passageway 47 and communicates at its outer end withvertical feed pipe 46.

Aflap valve 48 is swung by rotation ofshaft 49 selectively to position transversely ofvolute passage 45 ordrain 58 which communicates withvolute passage 45. Aresilient sealing element 51 is positioned around the mouth of drain against which flapvalve 48 seats, and is held by a sleeve extension fitting within the drain.Shaft 49 is preferably positioned within adrain recess 53 in the outer surface ofvolute passage 45 to minimize the obstruction to flow throughvolute passage 45.Flap valve 48 is normally seated against. sealingelement 51 by the action of aspring 54, one end of which is attached to the outer end of acrank arm 55 secured toshaft 48. The other end is fastened to ananchor bar 56.Flap valve 48 is selectively rotated to position transversely ofpassage 45, indicated aschain line position 48a, by asolenoid 57 which may be resiliently connected tocrankarm 55, as by a relativelystrong spring 58. The strength ofsolenoid 57 required to turnflap valve 48 to position 48a to shut oif the flow to feedpipe 46 is minimized by placingvalve 48 in thevolute passage 45 at the beginning of thedivergent discharge passageway 47, because at this point the velocity head of the liquid being pumped is not yet fully converted to positive pressure head. In other Words, the flap valve is positioned at the point where there is the least resistance to turning it by the solenoid.

Acap 59 is removably slid over the upper end offeed pipe 46 and rests on aspring clip 68 seated within anannular groove 61 in the outer surface ofpipe 46.Lateral spray tubes 62, which are fixed to and extend radially outwardly ofcap 59, communicate withfeed pipe 46. The top surfaces ofspray tubes 62 are provided with a series ofdischarge orifices 63 by which jets of washing fluid may be impingingly directed onto the dishes.

Referring now to FIGS. 2 and 5, a pressureresponsive unit 64 is rockingly secured to thefeed pipe 46 bystud 65. Theunit 64 encloses achamber 66 which communicates with the interior offeed pipe 46, as byflexible tubing 67. Apiston 68 freely floats withinchamber 66 and is secured to theactuating rod 26 which freely reciprocates throughcap 69 ofunit 64. The outside diameter ofpiston 68 is sufficiently smaller than the inside diameter ofchamber 66 to eliminate the frictional resistance of thepiston 68 sliding against thewall 70 ofchamber 66.

Pressure losspast piston 68 is prevented by a generally cylindrical flexible bladder "71 having one open and one closed end. Aperipheral bead 72 around the open end is sealed against thebase 73 ofchamber 66 by aflanged plate 74 which is tightened against thebase 73 by a T-nozzle 75. Theclosed end 76 ofbladder 71 contacts thehead 78 ofpiston 68 and confines any pressure Withinchamber 66 to that portion betweenbase 73 and thehead 78 orpiston 68 enclosed withinbladder 71.

Ahelical spring 79 encompassesrod 26 betweenpiston 68 andcap 69. Thespring 79 continually urges thepiston 68 normally to bottom inchamber 66 against T-nozzle 75. Thelateral passages 80 in T-nozzle 75 assure communication of pressure against a more effective area ofpiston head 78 even when it has bottomed against the orifice ofaxial passage 81 in T-nozzle 75 (as represented in phantom).

In actual operation a standard timing mechanism, not shown, regulates a cyclic operation of the automatic dishwasher. When the wash cycle begins, the washing fluid, which enters in response to the timing mechanism, by means not shown,entersthe inlet 13 ofpump 14 by gravity fromsump 12. At the same time themotor 33 is rotating theimpeller unit 34 to pump the washing fluid out through theperforations 43, by the rotation ofblades 37, into thevolute passage 45. Because theflap valve 48 is normally maintained acrossdrain 50 by the action ofspring 54, the flow throughpassage 45 continues throughvertical feed pipe 46. The pressure under which the fluid is pumped throughpipe 46 communicates throughflexible tubing 67 into thechamber 66 defined withinbladder 71 in pressureresponsive unit 64. This pressure causes thepiston 68 to move from its bottomed position against T-nozzle '75, as indicated by the chain lines in FIG. 5, by the outwardly rolling of thebladder 71 from its normal unfolded position.

The displacement ofpiston 68 axially displacesrod 26 against actuatingarm 25 to positionscreen 23 across the flow path throughsump 12. The rockable mounting ofunit 64 onstud 65 allows therod 26 to continuously engage the dishedend 28 as thearm 25 swings on its arc.

The washing fluid being pumped throughfeed pipe 46 also flows through thelateral spray tubes 62 and is forced out through thedischarge orifices 63 to impinge upon the dishes in cabinet 11. The food particles are thereby washed from the dishes and carried with the wash fluid throughgrille 18, the openings of which are of such a size as to retain utensils which might accidentally find their way to the bottom of cabinet 11. The fluid and food particles flowing throughgrille 18 are channeled acrossdeflection plate 20 ontoscreen 23, which has a mesh size that retains the food particles which would be large enough to clogorifices 62. The fluid passing throughscreen 23 re-enters inlet 1.3 ofpump 14 and is recirculated. This recirculation continues through the wash cycle. Of course, any pre-wash rinse or post-wash rinse cycles would recirculate in the same manner. M

It should be noted that any food particles which do penetratescreen 23 will be mechanically macerated by cuttingedges 44 onring 40 as the carrying fluid passes throughperforations 43.

At the end of any recirculating cycle, the timing mechanism causes thesolenoid 57 to energize, which institutes the drain cycle. Specifically, energizing the solenoid in turn rotatesshaft 49 to placeflap valve 48 across volute passage 45 (as represented by thechain position 48a in FIG. 3). Thedrain 50 thereby communicates with thepump cavity 35. As thevalve 48 closes the flow throughpassage 45 to feedpipe 46 the pressure inresponsive unit 64 is correspondingly reduced. This permitsspring 79, assisted by the weight ofscreen 23 and the food particles thereon, to move thepiston 68 towardbase 73. Retrac tion ofrod 26 aspiston 68 moves towardbase 73 swings the screen downwardly to thechain line position 23a in FIG. 2. In this position the flow of the washing fluid across the face of thescreen 23 washes the food particles therefrom to be carried into thisinlet 13 ofpump 14.

At the beginning of the drain cycle, fresh water may enter throughpipe 82 which is provided with a series ofnozzles 83 directed to impinge the water substantially across the face ofscreen 23a to assist in removal of the food particles retained thereon.

These food particles are mechanically macerated against the cutting edges 44 of thering 46 to a sufficiently small size to prevent clogging of the drain, or the sanitary system to which the drain is connected, as the fluid is evacuated from thedishwasher 10.

The above described operation is repeated through any number of wash or rinse cycles and provides a dishwasher in which the dishes can be placed without the necessity of tedious pre-removal of the food particles.

What is claimed is:

1. An automatic dishwasher having a washwater circulating cycle and a drain cycle comprising, a dishreceiving cabinet having a sump section, a drain, means to spray said washwater into said cabinet, a pump having an inlet communicating with the base of said sump section and a pump outlet passage, means to macerate the food particles entering said pump, valves means selectively to connect the outlet of said pump to the washwater spray means during the circulating cycle and to said drain during said drain cycle, movable screening means in advance of said pump inlet, pressure responsive means operatively connected to said movable screening means to position said screening means to remove the food particles from said washwater during the circulating cycle and to displace said screening means to release the retained food particles into said pump inlet during said drain cycle, and means for communicating the pressure of the washwater in said spray means with said pressure responsive unit.

2. An automatic dishwasher having a washwater circulating cycle and a drain cycle comprising, a dishreceiving cabinet having a sump section, a drain, means to spray said washwater into said cabinet, a pump having an inlet communicating with the base of said sump and a pump outlet passage, means to macerate the food particles entering said pump, valve means selectively to connect the outlet of said pump to the washwater spray means during the circulating cycle and to said drain passage during said drain cycle, a pivotable screen above said pump inlet, an actuating arm on said screen, a pressure responsive unit, said unit having a reciprocable actuating rod operatively engaging said actuating arm, means to extend and retract said rod in response to the pressure of the washwater in said spray means, pressure of the washwater in the spray means during said circulating cycle extending said rod to position said screen to remove food particles from said washwater, the pressure of the washwater in the spray means during said drain cycle retracting said rod to pivot said screen and release the food particles into said pump inlet.

3. An automatic dishwasher having a washwater circulating cycle and a drain cycle comprising, a dishreceiving cabinet having a sump section, a drain, a pump having an inlet communicating with the base of said sump, a pump outlet passage, discharge means to spray said washwater into said cabinet, a feed pipe connecting said pump outlet passage to said discharge means, valve means selectively to connect the outlet passage of said pump to said feed pipe during the circulating cycle and to said drain during said drain cycle, means to macerate the food particles entering said pump, a pivotable screen in advance of said pump inlet, an actuating arm on said screen, a pressure actuating unit, said unit having a reciprocable actuating rod operatively engaging said actuating arm, a pressure chamber in said unit, piston means responsive to the pressure in said chamber, said rod extensible and retractable by said piston means, said pressure chamber communicating with said feed pipe, the pressure of the washwater in the feed pipe during said circulating cycle extending said rod to position said screen to remove food particles from washwater entering said pump inlet, the pressure of the washwater in the feed pipe during the drain cycle retracting said rod to pivot said screen and release the food particles into said pump inlet.

4. An automatic dishwasher having a washwater circulating cycle and a drain cycle comprising, a dishreceiving cabinet having a sump section, a drain, a pump having an inlet communicating with the base of said sump section, a pump outlet passage, means to macerate the food particles entering said pump, discharge means to spray said washwater into said dish-receiving cabinet, a feed pipe connecting said pump outlet passage to said discharge means, valve means selectively to connect said pump outlet passage to said feed pipe during the circulating cycle and to said drain during said drain cycle, a pivotable screen, an actuating arm on said screen, a rockably mounted pressure responsive unit, said unit enclosing a piston chamber, a piston in said chamber, the outer diameter of said piston being smaller than the inner diameter of said chamber, one end of an actuating rod connected to said piston, the other end of said actuating rod operatively engaging said actuating arm, a flexible bladder Within said piston chamber enclosing a pressure chamber, resilient means to maintain said piston against said bladder, conduit means connecting said feed pipe to the pressure chamber enclosed within said bladder, the pressure of the washwater in the feed pipe during said circulating cycle extending said rod to position said screen to remove food particles from washwater entering said pump inlet, the pressure of the washwater in the feed pipe during the drain cycle allowing retraction of said rod to pivot said screen and release the food particles into said pump inlet.

5. An automatic dishwasher having a washwater circulating cycle and a drain cycle comprising a dish-receiving cabinet having a sump section, a drain, a pump having an inlet communicating with the base of said sump section, said pump having an impeller unit, a perforated macerating ring circumscribing said impeller unit, a pump outlet passage exteriorly of said macerating ring, discharge means to spray said washwater into said dish-receiving cabinet, a feed pipe connecting said pump outlet passage to said discharge means, valve means selectively to connect said pump outlet to said feed pipe during the circulating cycle into said drain during said drain cycle, a pivotable screen, an actuating arm on said screen, a pressure responsive unit, said unit having a reciprocable actuating rod operatively engaging said actuating arm, means urging said rod to retracted position, and means to extend said rod in response to the pressure of the washwater in said feed pipe during said circulating cycle to position said screen to remove food particles from washwater entering said pump inlet, the reduced pressure of the washwater in the feed pipe during said drain cycle allowing retraction of said rod to pivot said screen and release the food particles into said pump inlet.

6. An automatic dishwasher having a washwater circulating cycle and a drain cycle comprising, a dish-receiving cabinet having a sump section, a pump having an inlet communicating with the base of said sump section, said pump inlet opening into a pump cavity, an impeller unit within said cavity, a perforated macerating ring circumscribing said impeller unit, a volute passage leading outwardly of said macerating ring, a drain communicating with said volute passage, discharge means to spray said washwater into said dish-receiving cabinet, a feed pipe connecting said volute passage to said discharge means, valve means selectively to connect said volute passage to said feed pipe during said circulating cycle and to said drain during said drain cycle, a pivotable screen, an actuating arm on said screen, a pressure responsive unit, said unit having a reciprocable actuating rod operatively engaging said actuating arm, means urging said rod to retracted position, and means to extend said rod in response to the pressure of the washwater in said feed pipe during said circulating cycle to position said screen to remove food particles from washwater entering said pump inlet, the reduced pressure of the washwater in the feed pipe during said drain cycle allowing retraction of said rod to pivot said screen and release the food particles into said pump inlet.

7. An automatic dishwasher having a washwater circulating cycle and a drain cycle comprising, a dish-receiving cabinet having a sump section, a drain, a pump having an inlet communicating with the base of said sump section, a pump outlet passage, means to macerate the food particles entering said pump, discharge means to spray said washwater into said dish-receiving cabinet, a feed pipe connecting said pump outlet "to said discharge means, a valve shaft, a flap valve mounted on said shaft'and adapted selectively to direct flow through said drain or said feed pipe, resilient means normally positioning said valve to direct flow through said feed pipe, a solenoid operatively connected to rotate said shaft, actuation of said solenoid positioning said valve to direct flow through said drain, a pivotable screen, an actuating arm on said screen, a pressure responsive unit, said unit having a reciprocable actuating rod operatively engaging said actuating arm, means urging said rod to retracted position, and means to extend said rod in response to the pressure of the wash- Water in said feed pipe during said circulating cycle to position said screen to remove food particles from Washwater entering said feed pipe, the reduced pressure in the feed pipe during said drain cycle allowing retraction of said rod to pivot said screen and release the food particles into said pump inlet.

8. An automatic dishwasher having a washwater circulating cycle and a drain cycle comprising, a dish-receiving cabinet having a sump section, a pump having an inlet communicating with the base of said sump section, said pump inlet opening into a pump cavity, an impeller unit Within said cavity, a perforated macerating ring circumscribing said impeller unit, a volute passage leading outwardly of said macerating ring, a drain communicating with said volute passage, discharge means to spray said Washwater into said dish-receiving cabinet, a feed pipe connecting said volute passage to said discharge means, a valve shaft, a flap valve mounted on said shaft and adapted selectively to direct flow through said drain or said feed pipe, resilient means normally positioning said valve to direct flow through said feed pipe, a solenoid operatively connected to rotate said shaft, actuation of said solenoid positioning said valve to direct flow through said drain, said solenoid being actuated during said drain cycle, a pivotable screen, an actuating arm on said screen, a pressure responsive unit, said unit having a reciprocable actuating rod operatively engaging said actuating arm, means urging said rod to retracted position, and means to extend said rod in response to the pressure of the wash Water in said feed pipe during said circulating cycle to position said screen to remove food particles from Washwater entering said pump inlet, the reduced pressure of the washwater in the feed pipe during said drain cycle allowing retraction of said rod to pivot said screen and to release the food particles into said pump inlet.

References Cited in the file of this patent UNITED STATES PATENTS 1,653,473 Schulz Dec. 20, 1927 2,629,390 Walker Feb. 24, 1953 2,681,658 Meeker June 22, 1954 2,729,219 Smith Jan. 3, 1956

Claims (1)

1. AN AUTOMATIC DISHWASHER HAVING A WASHWATER CIRCULATING CYCLE AND A DRAIN CYCLE COMPRISING, A DISHRECEIVING CABINET HAVING A SUMP SECTION, A DRAIN, MEANS TO SPRAY SAID WASHWATER INTO SAID CABINET, A PUMP HAVING AN INLET COMMUNICATING WITH THE BASE OF SAID SUMP SECTION AND A PUMP OUTLET PASSAGE, MEANS TO MACERATE THE FOOD PARTICLES ENTERING SAID PUMP, VALVES MEANS SELECTIVELY TO CONNECT THE OUTLET OF SAID PUMP TO THE WASHWATER SPRAY MEANS DURING THE CIRCULATING CYCLE AND TO SAID DRAIN DURING SAID DRAIN CYCLE, MOVABLE SCREENING MEANS IN ADVANCE OF SAID PUMP INLET, PRESSURE RESPONSIVE MEANS OPERATIVELY CONNECTED TO SAID MOVABLE SCREENING MEANS TO POSITION SAID SCREENING MEANS TO REMOVE THE FOOD PARTICLES FROM SAID WASHWATER DURING THE CIRCULATING CYCLE AND TO DISPLACE SAID SCREENING MEANS TO RELEASE THE RETAINED FOOD PARTICLES INTO SAID PUMP INLET DURING SAID DRAIN CYCLE, AND MEANS FOR COMMUNICATING THE PRESSURE

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