US3906967A

US3906967A - Dishwasher

Info

Publication number: US3906967A
Authority: US
Inventors: Richard P Bergeson
Original assignee: Maytag Corp
Current assignee: Maytag Corp
Priority date: 1974-05-08
Filing date: 1974-05-08
Publication date: 1975-09-23
Anticipated expiration: 1992-09-23
Also published as: CA1037828A; CA1016842A; US3963046A

Abstract

A dishwasher construction including a generally concentric pump and covered sump construction disposed on a generally vertical axis and driven by a drive belt that is in turn driven by a motor spaced laterally from the axis of the concentric pump. The motor may be mounted in a first position relatively adjacent the rear of the dishwasher and generally opposite the access door whereby the weight of the motor opposes the weight of the door in the open position when the dishwasher is used as a freestanding appliance and may be mounted in a second location relatively adjacent the front of said dishwasher whereby the drive motor is easily accessible when the dishwasher is installed as a built-in appliance.

Description

nited States Patent Sept. 23, 1975 ergeson DISHWASHER [75] Inventor: Richard P. Bergeson, Newton, Iowa [73] Assignee: The Maytag Company, Newton,

Iowa

[22] Filed: May 8, 1974 [21] Appl. No.: 467,868

[52] US. Cl. 134/104; 134/186; 415/143; 415/121 G; 417/315; 137/565 [51] Int. Cl. B08B 3/02 [58] Field of Search 417/315, 423, 424; 415/121 G, 143; 134/176, 186, 191, 104, 111; 137/565 [56] References Cited UNITED STATES PATENTS Primary Examiner l-lenry T. Klinksiek Attorney, Agent, or FirmRichard L. Ward [57] ABSTRACT A dishwasher construction including a generally concentric pump and covered sump construction disposed on a generally vertical axis and driven by a drive belt that is in turn driven by a motor spaced laterally from the axis of the concentric pump. The motor may be mounted in a first position relatively adjacent the rear of the dishwasher and generally opposite the access door whereby the weight of the motor opposes the weight of the door in the open position when the dishwasher is used as a freestanding appliance and may be mounted in a second location relatively adjacent the front of said dishwasher whereby the drive motor is easily accessible when the dishwasher is installed as 21 3,244,105 4/1966 La Flame ..134/186X b iltin appliance. 3,542,496 11 1970 Bergeson 1417 4231! 3,576,378 4/1971 Hi1manowski.... 134/186X 15 Clams, 4 Drawmg Flgures 14-5 C M g /4 /7 m/ my I fi 74 Ex a? /74 7/ M;

j m; M! 30 me l 5/ 0a i /70 M4- \35 /4 a4 ma 5a 53 m/ f I 42 42 A2 /M I #9 ;a E 1;; 7 4 a I /3L lfi g; 5

m my

US Patent Sept. 23,1975 Sheet 1 of 3 3,906,967

US Patent Sept. 23,1975 Sheet 2 of3 3,906,967

US Patent Sept. 23,1975

Sheet 3 of 3 DISHWASHER BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a dishwasher and more par ple, disclose respresentative dishwasher constructions having a generally upstanding axial flow pump disposed in the sump or lower portion of the tub and driven by a concentric motor depending from the washing container. Other United States patents representing a more recent direction in dishwasher construction include the following: U.S. Pat. Nos. 3,430,861; 3,491,780; 3,502,090; and 3,575,185. These patents disclose various dishwasher constructions including a dual pumping system generally depending from the sump or fluid container and driven by a coaxially disposed motor and further including a filtering system associated with the recirculation pump. A still further system is disclosed in U.S. Pat. No. 3,542,594 and comprises a sump construction depending from the washing container for housing a filtering system and being in fluid communication with a remote pump'and motor construction.

SUMMARY OF THE INVENTION It is an object of the instant invention to provide an improved dishwasher construction.

It is a further object of the instant invention to provide a dishwasher construction having a compact combination sump and pump construction generally depending from the washing chamber. U i

It is a furtherobject of the instant invention to provide a dishwasher construction having a generally concentric sump and pump construction with the pump being driven by a laterally disposed motor-connected to the pump through a drive belt.

It is a still further object of the instant invention to provide a dishwasher construction including acombination sump and pump assembly including a depending housing defining a sump and further defining-concentric recirculation and drain pump cavities in which impellers are rotatable by a laterally disposed motor and interconnecting drive belt." n

These objects are achieved in a dishwasher construction including housing means depending from the bot tom wall of awashing container and defining a sump and a pair of pump cavities having fluid communication with the washing chamber. The combination includes a sump cover and fine mesh filtering meansfor removing particles from the fluid recirculated to the washing chamber and further includes a recirculation: Pump and n BRIEF DESCRIPTION OF THE DRAWINGS The drawings illustrate a preferred embodiment of the invention .withsimilar numerals referring to similar parts throughout the several views, wherein: 7

FIG. 1 is a fragmentary view partially broken away and sectioned toshow the dishwasher as adapted for operation as a freestanding portable appliance; FIG. 2 is a view similar to FIG. 1 showing the dishwasherv as modifiedfor operation as a built-in appliance; i

FIG. 3 is a cross-section view of the dishwasher as generally shown in FIG. 2 and comprising, primarily, a

vertical section of the combination sumpand'pump construction; and r n e I n FIG. 4is a fragmentary plan viewof the dishwasher apparatus of .FIGS. 2.and 3 as partially sectioned and taken generally along lines 4-4 of FIG. 3.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring to the drawings there is shown in FIG. 1 a dishwasher l0.constructed for operation as a portable freestanding appliance and adapted for optionalconversion to a built-in appliance. It has become desirable to provide a household dishwashing apparatus that may be used, initially at least, as a freestanding portable ap pliance and then,at a later date, be converted for use as a built-in appliance. Such a covertible dishwasher may be used as a freestanding portable appliance where it is not feasible or desirable to install the dishwasher as a built-in appliance. The same appliance, if convert ible, can later be installed as a. built-in when it becomes possible. It is recognized that these two differentmodes of operation require-different structure as particularly related to cabinetry, overall stability, and liquid control. The dishwasher l0 disclosed in this application is' convertibleand provides distinct advantages in operation and conversion as compared to prior art devices.

Referring specifically to FIG. 1 therefisshown a fragmentary lower portionof the dishwasher as constructed for freestanding portable use. The dishwasher 10 includes a tub or fluid container 11 of which only a lower portion is shown and to which is attached a pair of side supports 14 extending downwardly and being fixed at the lower end to a base member 15. The base member 15 is mounted on a plurality of casters 16 which engage ahorizontal surface 18 for movably supporting the dishwasher l0 thereon.

A cabinet or enclosure 19, attached along the lower edge to the base member 15, extends upwardly along the sides and .rear of the appliance. A door 20 is mounted on the front of the dishwasher and is supported on the side supports 14 through a pair of hinges 21. A spring 24 is connected between the end of the hinge arm 25 and a bracket 26 fixed to the side support 14. The spring 24, at least partially, counterbalances the weight of the door 20 as it moves to the open position. Disposed below the door 20 is a removable access panel 28 providing accessibility into the compartment below the liquid container 11. A caster cover 29 is disposed below the access panel 28 for at least partially covering'the pair of front casters 16.

The fluid container or tub ll defines, as best shown in FIG. 3, a chamber32 having a bottom wall 30 which includes a generally central recess 31 and opening 34 for effecting a recirculation of fluid to the washing chamber 32 and a drain pump for removing washing fluid from the chamber 32, as will be described in detail hereinafter. As shown in FIG. I, the pumps are connected to the rearwardly disposed drive motor 40 by a stretch belt 41.

The fractional horsepower, bidirectional drive motor 40 is mounted on the base of the freestanding dish washer of FIG. 1 through

resilient spacers

44 and 45 and auxiliary bracket 46. It is particularly noted that the placement of the motor 40 toward the rear of the appliance provides a gravity force tending to counterbalance forces applied to the door in the open position to assist in the prevention of tipping of the portable appliance. The location of the motor 40 is further shown by the broken line outline 48 in FIG. 4.

As a measurement of the stability or resistance to tipping of a portable dishwasher when a force is applied to a door in the open position, one standard accepted in the industry requires that the machine not tip when a 50-pound load is applied at the outer edge of an open door with no dishes or water in the dishwasher. Prior art patents disclose a number of auxiliary devices which were necessary to prevent tipping including leg braces, support levers, and breakaway doors, for example. The placement of the motor, which weighs approximately 12%. pounds, toward the rear of the appliance as shown in FIG. 1, however, advantageously distributes the weight of the dishwasher to obviate the need for auxiliary bracing or breakaway devices.

A top cover or top panel for the portable appliance is provided but is not shown in FIG. 1. Similarly, the portable appliance is provided with a faucet adapter assembly to connect the dishwasher to the water supply line for filling the appliance and to position the drain conduit for conducting washing fluid from the appliance to an external drain. The faucet adapter assembly and connecting hoses, though not shown in FIG. 1, are at least partially housed in the rear compartment 49 between the tub I] and the rear wall of the cabinet 19.

Referring to FIG. 2 the same basic dishwashing apparatus is shown converted for installation as a built-in appliance. The basic dishwashing apparatus includes the liquid container 11 defining a washing chamber and supported on the pair of side panels 14. The combination sump and pump assembly 35 remains the same as shown in FIG. 1. The hinged door 20, the mounting thereof, and the access panel 28 are also the same as in FIG. 1. The spring 24 is depicted in an alternate position to show the adjustable feature thereof.

A number of components, however, have been removed in the conversion between the freestanding appliance and the built-in appliance. Some of these components are simply unnecessary in the built-in installation. It is clear that the enclosure cabinet 19 has been removed as has been the base 15 and casters 16 connected thereto. The caster cover 29 and top cover (notnot a major factor. The bracket 46 and resilient spacers 44, for supporting the motor on the base 15 at the rear of the machine have been removed and replaced with an alternate bracket 50 attached, as in FIG. 3, to one of the side supports 14. The bracket 50 includes a pair of horizontally extending flanges 51 which are clamped to rings 54 resiliently fixed to the ends of the motor 40. The drive motor 40 is therefore optionally mounted in either of two positions. The distance between the drive motor 40 and the center line of the sump and pump assembly 35 is the same in each construction and thus the same drive belt 41 may be used for both motor locations.

Y The appliance of FIG. 2 is supported on a plurality of floor-engaging members including a pair of screw-in feet 55 at the front of the machine which are easily adjustable at the front of the machine and also including a pair of pivotally mounted feet 56 at the rear of the side supports 14. The pivoted feet 56 are also adjustable at the front of the machine through a pair of hexheaded elongated members 58 extending, as in FIGv 4, from the front of the machine to the rear of the machine into threaded engagement with a pivot bar 60 for moving the floor engaging foot 56 about pivot pin 61 as more particularly disclosed and claimed in US. Pat. No. 3,750,989 issued Aug. 7, 1973, to Richard P. Bergeson and assigned to the assignee pf the instant invention.

A toeboard panel 64 is added to the dishwasher below the access panel 28 to enclose the lowermost portion of the front of the machine upon installation as a built-in appliance. The additional components neces- ,sary to convert the dishwasher from a portable freestanding device to a built-in appliance, such as motor bracket 50, supporting

feet

55 and 56, and toeboard 64 as described above, would be available as accessories.

In FIG. 3 there is shown a generally vertical cross section of the lower portion of the washing chamber 32 and the combination sump and pump assembly 35. As previously indicated, the tub 11 is supported by a pair of side legs or supports 14 having reinforcing

flanges

65 and 66 extending along the slanting top and along the bottom, respectively, as best seen in FIG. 3 and flange 68 along the front as best seen in FIG. 4. The bottom flanges 66 provide means for receiving the floor engaging members, such as the two screw-in legs 55 positioned at the front of the machine. These legs 55 may be adjusted to vary to height of the dishwasher within the provided opening when installed as a built-in appliance.

FIG. 3 also shows a portion of the water inlet system including a valve 69 mounted on the side support 14. A conduit 70 from valve 69 extends toward the rear of the machine and to the outside of the tub l1 and connects with the inlet system 71 for directing liquid into the washing chamber 32. The inlet system 71 along the side of the tub 11 includes the necessary air gap. A float device 74, as in FIG. 4, may be provided for control of the water inlet system. i

A heater, as shown in FIGS. 3 and 4, is provided within the washing chamber 32 for raising the temperature therein and includes an elongated arcuate element 75 supported by a plurality of supports 76 attached to the fluid container bottom wall 30.

As previous indicated, the bottom wall 30 includes a generally centrally located recess 31 having a flange 78 defining an opening 34 for receiving the combination sump and pump assembly 35. The main sump-pump housing 80 is generally annular and is assembled into the opening 34 in the bottom wall from inside the washing chamber 32 so that the upper flange 81 of the housing engages the recessed flange 78 of the bottom wall 30. The flange 81 is connected to the bottom wall recessed flange 78 with a plurality of threaded members 84, such as in FIG. 4 and retainer clips 85, as in FIG. 3. An annular seal 86 is disposed at the joint to prevent liquid leakage from the washing chamber 32.

A first portion 88.0f the housing 80 depending from the bottom wall 30 defines a generally annular sump 89 communicating and facing generally upwardly toward the washing chamber 32 as shown best in FIGS. 3 and 4. Disposed generally below the sump 89 is a first pump cavity 90 defined by a second housing portion 91 and having a volute form for receiving fluid from the sump 89 and through which the fluid is pumped to the fluid distribution system for effecting washing of-articles in the washing chamber 32.

Referring to FIG. 4, inner portions of the sump and pump assembly 35 including the recirculation pump cavity 90 are shown by removing a number of components of the assembly. Also referring to FIG. 4, there is shown outlet 94 extending from the end of the recirculation pump'cavity 90 for connection with the up wardly extendingconduit 95 as shown in FIGS. 1 and 2 which carries a portion of the fluid from the recirculation pump cavity 90 to an upper spray arm (not shown). The recirculation pump cavity 90 is also connected to the lower fluid distribution system 98 as shown in FIG. 3 as will be more fully explained hereinafter.

Disposed below the recirculation pump cavity 90 is a radially smaller and generally annular drain pump cavity 100 defined by a third housing portion 101 for accommodating flow of fluids from the dishwasher sump 89 to an external drain. The cavity 100 includes an inlet 104, as in FIG. 3, and an outlet 105, as in FIG. 4. The inlet 104 communicates with the sump 89 through a conduit 106 defined by the housing 80. Also firmed as a part of the main housing 80 is a depending sleeve 108 for supporting a pump shaft 109 through a pair of bearings 110 which are retained within the sleeve-like housing 108 by end plate 111, spacer sleeve 114, and the shoulder 115.

A closed vane recirculation impeller 116 is mounted on the shaft 109 for operation within the recirculation pump cavity 90. The recirculation impeller 116 includes a disk-like lower base 118 connected to the hub 119 and also includes an annular cover 120 defining a central opening 121 into a plurality of arcuate vanes 122. A drain pump impeller 124 is disposed within the drain pump cavity 100 and includes a plurality of downwardly extending open vanes 125.

A divider 126 is disposed below the recirculation pump impeller 116 to effectively divide the recirculation and

drain pump cavities

90 and 100. The divider 126 is fixed to the housing-80 by a pair of screws 128, as in FIG. 4, and includes an inner lip 129 juxtaposed to the hub 119 of the recirculation impeller 116. The divider 126 functions as a proximity seal and flow regulator as described in U.S. Pat. No.3,542.496 issued Nov. 24, 1970 to Bergeson et al and assigned to the assignee of the instant invention. Disposed below the drain pump impeller is a liquid sealiarrangement 130 including a liquid slinger to preveritw'ater from enter ing the bearings 110. A pulley 134 is secured to the lower end of the pump shaft 109 to effect rotation of the pump shaft 109 and the pair of

impellers

116, 124.

The pump pulley 134 is connected to the motor pulley 135 by a round polyurethane drive belt 41. The motor .40 is operable in first and second directions for driving the pump shaft 109 to effect, in one direction of rotation, a recirculation of fluid to said washing chamber 32 while maintaining a relatively small posi- ;tive pressure. head at the outlet 105 of the drain pump cavity 100 and to effect, in the opposite direction, a substantial increase in output pressure of the drain pump for draining fluid from the washing chamber 32 and sump 89 while maintaining recirculation of fluid by the recirculation pump, but at a significantly lower rate, as long as'su fficient fluid remain in the sump 89.

An intermediate or internal housing 138 is disposed within the sump as in FIG. 3. The intermediate housing 138 has been removed from the assembly in FIG. 4 but is attached to the main housing 80 by a plurality of screws 139-along the recirculation pump cavity 90 as shown in FIG. 4. The intermediate housing 138 comprises a cover 140for the recirculation pump and defines an axial inlet 141 into the recirculation pump cavity 90. The intermediate housing 138 also defines an outlet 144 from the recirculation pump at the end of the volute cavity 90 and forms an upwardly extending conduit or tube 145 from the outlet 144 for connection with the recirculation means 98 disposed in the lower portion of washing chamber 32. The upper end of the manifold or tube 145 includes an internal hub 146 for fixedly supporting a shaft 148 on which a spray device is mounted and as will be described hereinbelow. The intermediate housing 138 further includes a plurality of generally upwardly extending ribs 149 for supporting the upper end of the tube 145 and the shaft 148 fixed therein.

The fluid distribution system 98 includes an upstanding fluid conduit or fluid distribution hub 150 having a plurality of internal ribs 151 supporting a pair of bearings 154 for rotational support of the hub 150 on the shaft 148. The lower end of the conduit or hub 150 engages a seal 155 disposed in a groove of the upper portion of theupwardly extending tube 145 and interlocked with the tube 145 to prevent rotation of the seal 155. The main spray arm 158 is mounted on the upstanding fluid conduit or hub 150 for rotation therewith. Openings 159 in opposite sides of the fluid conduit or hub 150 at the spray arm 158 accommodate the fluid flow from the recirculation pump cavity 90 to the outwardly extending spray arm 158. A nozzle 160 extends upwardly from the end of the fluid conduit or hub 150 for distributing washing fluid up into the intermediate regions of the dishwashing chamber 32. The nozzle 160 is fixed to the end of the fluid conduit or hub 150 for rotation therewith and retaining the spray arm 158 on the conduit or hub 150.

An upper housing portion or cover 161 is attached to the main housing 80 along the upper flange 81 of the main housing 80 at screws 162 as in FIG. 4. The cover 161 is substantially imperforate and includes a generallycentral opening 164 for accommodating the upwardly extending fluid distribution conduit 150. A sea] is disposed at the opening 164. Along the periphery of the cover as best shown in FIGS. 3 and 4 are a plurality of generally upstanding radiating ribs 165 that extend radially beyond the outer horizontal flange 166 of the cover. The vanes or ribs 165 are radially spaced around the periphery of the cover 161 to define a plurality of tunnels having, because of downwardly extending vertical flange 168, a generally 90 turn between the washing chamber 32 and the sump 89.

The outer periphery of the cover 161 thus defines a strainer between the washing chamber 32 and the sump 89 to prevent flow of large particles from the washing chamber 32 into the sump 89. The spacing of the vanes 165, the radial extension of the vanes 165 relative to the horizontal flange 166, and the 90 turn defined by the horizontal flange 166 and the downwardly extending vertical flange 168 prevent flow from the washing chamber 32 of particles or articles exceeding predetermined dimensional characteristics. This flow control device or strainer thus prevents articles from getting into the drain pump cavity 100 and blocking or damaging the impeller 124 thereof.

A lower surface of the cover 161 defines a downwardly facing annular groove 169 generally aligned with a similar upwardly facing annular groove 170 in the lower portion of the sump 89. These

grooves

169, 170 receive the end rings ofa generally annular and cylindrical fine mesh filter screen 171 for support within the sump 89. The filter screen 171 thus effectively divides the sump 89 into first and second portions with the inlet of the conduit 106 to the drain pump cavity 100 being outside or upstream from the filter 171, while the inlet 141 to the recirculation pump cavity 90 is radially within or downstream relative to the filter 171.

The disposition of the filter 171 within the sump 89 between the inlets of the drain and recirculation pumps effectively establishes two fluid paths from the washing chamber 32. A first fluid path extends from the washing chamber 32 through the stainer, the outer sump portion, and the filter screen 171 into the inner sump portion for conduction to the inlet 141 of the recirculation pump. The fluid is then pumped to the fluid distribution means. A second fluid path extends from the washing chamber 32 through the strainer to the outer sump portion and from the outer sump portion through the housing-defined fluid duct 106 to the inlet 104 of the drain pump cavity 100. From the drain pump cavity 100 the fluid is pumped to an external drain through the drain pump outlet 105 when the pump is driven in the predetermined drain direction.

Disposed within the annular filter screen 171 is an auxiliary spray device for effecting a cleaning or backflushing of the filter-screen. The device includes an arm 174 comprising two depending spray tubes 175 having an elongated slit along the surface adjacent to the screen 171 for spraying liquid onto the downstream side of the screen. The arm 174 is fixed to and rotatable with the upstanding fluid conduit or hub 150. Fluid flows from the upstanding fluid conduit or hub 150 into the spray arm 174 through the openings 176 aligned with the spray arm 174.

Thus, with the motor 40 operating in a first direction to drive the pump shaft 109 and recirculation impeller 116 in a clockwise direction, as viewed in FIG. 4, the first fluid flow path is established and a high pressure recirculation of fluid to the washing chamber 32 is effected. In this first direction of rotation the drain pump is operable for maintaining a generally static fluid pressure in the drain line to prevent flow of fluid from the washing chamber while preventing backflow of fluid from the drain line into the sump 89. In the opposite direction of rotation the recirculation pump is still operable for effecting fluid flow into the fluid distribution conduit or hub 150 at a reduced rate, but the drain pump becomes operable for effecting a substantial increase in pumping pressure at the drain pump outlet to establish the second fluid flow path and effect a relatively rapid draining of fluid from the washing chamber.

The output of the recirculation pump is effectively divided between the upper spray arm (not shown), the spray nozzle 160, the main wash arm 158, and the auxiliary filter cleaning spray arm 174. With the recirculation pump operating in the clockwise direction as in FIG. 4 to produce an output of approximately 35 gallons per minute, the relative distribution of fluid from the outlet is as follows: top spray arm 10.1 gpm; spray nozzle 9.6 gpm; lower spray arm 9.6 gpm; and backwash auxiliary spray arm 5.7 gpm.

One feature of the construction of the instant invention not previously discussed herein relates to the preassembly of the combination sump and pump construction. The entire assembly 35, including the main housing 80, the cover 161, the internal housing 138, and the upstanding fluid distribution conduit or hub as well as all of the internal operating components may be preassembled on a bench stand. The completed assembly 35 may then be inspected and tested prior to installation in the Washing chamber bottom wall 30. The combination sump and pump assembly 35 may also be removed as a unit to provide more convenient serviceability,

The present construction thus provides an improved dishwasher apparatus achieving a unique combination of the pumping and filtering apparatus with the dishwasher sump. The combined construction permits the achievement of all the advantages of the dual pump and filtering system while eliminating a number of components heretofore required. In addition to operational advantages, the present construction achieves improved accessibility and serviceability of the wash system components.

In the drawings and specification, there has been set forth a preferred embodiment of the invention and although specific terms are employed these are used in a generic and descriptive sense only and not for purposes of limitation Changes in form and the proportion of parts as well as the substitution of equivalents are contemplated as circumstances may suggest or render expedient without departing from the spirit or scope of the invention as further defined in the following claims.

1 Claim:

1. A combination sump and pump assembly for a dishwasher including a container means defining a washing chamber and having a bottom wall with a generally central opening therein, the combination comprising: first housing means effectively fixed to said bottom wall generally aligned with and depending from said opening for defining a sump chamber disposed generally below and in fluid communication with said washing chamber; generally annular fine mesh filter means disposed in said sump chamber and forming a first sump portion from said filter means and a second sump portion downstream from said filter means; a cover attached to said first housing means separating said second sump portion from said washing chamber and defining a fluid strainer between said washing chamber and said first sump portion; fluid distribution means including means within said sump chamber for defining a fluid distribution conduit extending upwardly therethrough; second housing means defining a recirculation pump cavity disposed generally below said first housing means and having an inlet in fluid communication with said second sump portion and an outlet in fluid communication with said fluid distribution conduit; third housing means disposed generally below'said first housing means and defining a drain pump cavity having an inlet in fluid communication with said first sump portion and an outlet in fluid communication with an external drain; a first impeller operable in said recirculation pump cavity for effecting flow of fluid from said first sump portion through said filter means and said second sump portion into said recirculation pump cavity for pumping to said fluid distribution conduit; a second impeller operable in said drain pump cavity for effecting flow of fluid and particles therein from said first sump portion to said drain pump cavity and to said external drain; and means for supporting said first and second impellers for rotation within said pump cavities.

2. A combination sump and pump assembly for a dishwasher as defined in claim 1 wherein at least a portion of said second and third housing means is formed integrally and coaxially with said first housing means.

3. A combination sump and pump assembly for a dishwasher as defined in claim 1 wherein said fluid distribution conduit extends generally upwardly through said second sump portion and through said cover for conduction of fluid from said recirculation pump cavity to said washing chamber. I

4. A combination sump and pump assembly for a dishwasher as defined in claim 1 wherein said strainer comprises a plurality of generally upstanding radiating spaced vanes defining a plurality of tunnels into said first sump portion.

5. A combination sump and pump assembly for a dishwasher including a container means defining a washing chamber and including a bottom wall with a generally central opening therein, the combination comprising: housing means effectively fixed to said bottom wall generally aligned with and depending from said opening for defining a sump chamber disposed generally below and in fluid communication with said washing chamber; generally annular fine mesh filter means disposed within said sump chamber and forming a first sump portion upstream from said filter means and a second sump portion downstream from said filter means; fluid distribution means including means within said second sump portion for defining a fluid distribution conduit extending upwardly therethrough; a generally annular imperforate cover attached to said housing means generally aligned with said central opening for accommodating said fluid distribution conduit and being disposed for separating sais second sump portion from said washing chamber and for defining a fluid strainer between said washing chamber and said first sump portion; a recirculation pump cavity defined by said housing means below said sump chamber and having an inlet in fluid communication with said second sump portion and an outlet in fluid communication with said fluid distribution conduit; a drain pump cavity defined by said housing means below said recirculation pump cavity and having an inlet in fluid communication with said first sump portion and an outlet in fluid communication with an external drain; a first impeller operable in said recirculation pump cavity for effecting flow of fluid from said washing chamber through said strainer, said first sump portion, said filter means and said second sump portion into said recirculation pump cavity for pumping to said fluid distribution conduit; a second impeller operable in said drain pump cavity for effecting flow of fluid and particles therein from said washing chamber through said strainer and said first sump portion to said drain pump cavity and to said external drain; and means for supporting said first and second impellers for rotation within said pump cavities.

6. A combination sump and pump assembly for a dishwasher as defined in claim 5 wherein said strainer includes a plurality of generally upstanding radiating spaced vanes along the periphery of said cover for preventing flow into said first sump portion of objects exceeding a predetermined dimensional characteristic.

7. A combination sump and pump assembly for a dishwasher as defined in claim 5 wherein said housing means defines a fluid conductor from said first sump portion to the inlet of said drain pump cavity. r

8. A combination sump and pump assembly for a dishwasher as defined in claim 5 wherein said imperforate cover, said housing means and said fine-mesh filter means are generally concentric to the axis of rotation of said recirculation pump impeller and said drain pump impeller. I a

9. A combination sump and pump assembly for a dishwasher as defined in claim 8 wherein said housing means and said imperforate cover define means for cooperatively supporting said filter means.

10. A dishwasher comprising: container means defining a washing chamber and including a bottom wall having a generally central opening therein; housing means effectively fixed to said bottom wall and generally aligned with and depending from said opening for defining a sump chamber disposed generally below and in fluid communication with said washing chamber; generally annular fine mesh filter means disposed within said sump chamber and forming a first sump portion upstream from said filter means and a second sump portion downstream from said filter means; fluid distribution means including means within said second pump portion for defining a fluid distribution conduit extending upwardly therethrough; a generally annular imperforate cover attached to said housing means aligned with said central opening for accommodating said fluid distribution conduit and being disposed for separating said second pump portion from said washing chamber and for defining a fluid strainer between said washing chamber and said first sump portion; a recirculation pump cavity defined by said housing means and having an inlet in fluid communication with said second sump portion and an outlet in fluid communication with said fluid distribution conduit; a drain pump cavity defined by said housing means and having an inlet in fluid communication with said first sump portion and an outlet in fluid communication with an external drain; a first impeller operable in said recirculation pump cavity for effecting flow of fluid from said sump portion through said filter means and said second sump portion into said recirculation pump cavity for pumping to said fluid distribution conduit, said fluid distribution means including means including rotatable rccirculation means mounted on and in fluid communication with said fluid distribution conduit and operable for spraying into said washing chamber for removing particles from articles contained therein; auxiliary spray means mounted on and in fluid communication with said fluid distribution conduit and disposed within said second cavity portion for flushing filtered particles from said fine mesh filter means; a second impeller operable in said drain pump cavity for effecting flow of fluid and particles therein from said first sump portion to said drain pump cavity for pumping to said external drain; and means for operating said first and second impellers.

11. A dishwasher as defined in claim wherein a drain conduit between said first sump portion and the inlet of said drain pump cavity is defined by said housing means.

12. A dishwasher as defined in claim 10 wherein said means for operating the first and second impellers includes a drive motor having an axis generally parallel to the axis of said pumps.

13. A dishwasher as defined in claim 12 wherein said motor axis is spaced from the axis of said pumps and is drivingly connected to said impellers by a drive belt.

14. A dishwasher comprising: container means defining a washing chamber and including a bottom wall having a generally central opening therein; structural support means connected to said container means for support thereof on a generally horizontal surface; fluid recirculation means for effecting a washing of articles in said washing chamber; housing means effectively fixed to said bottom wall and generally aligned with and depending from said opening for defining a sump chamber disposed generally below and in fluid communication with said washing chamber; generally annular fine mesh filter means disposed within said sump chamber and forming a first sump portion upstream from said filter means and a second sump portion downstream from said filter means; an imperforate cover attached to said housing means generally aligned with said central opening and being disposed for separating said second sump portion from said washing chamber and for defining a fluid strainer between said washing chamber and said first sump portion; a recirculation pump cavity defined by said housing means and having an inlet in fluid communication with said second sump portion and an outlet in fluid communication with said fluid recirculation means; a drain pump cavity defined by said housing means and having an inlet in fluid communication .with said fluid sump portion and an outlet in fluid communication with an external drain; a first impeller operable in said recirculation pump cavity for effecting flow of fluid from said sump portion through said filter means and said second sump portion into said recirculation pump cavity for pumping to said fluid recirculation means', said fluid recirculation means being operable for spraying fluids into said washing chamber to remove particles from articles contained therein and for spraying fluids onto said fine mesh filter means to flush filtered particles therefrom into said first sump portion; a second impeller operable in said drain pump cavity for effecting flow of fluid and particles therein from said first sump portion to said drain pump cavity for pumping to said external drain; means depending from said housing means for rotatively supporting said impellers; and pump drive means including a motor having an axis of operation parallel to the axis of operation of said recirculation and drain pump impellers and spaced laterally therefrom.

15. A dishwasher as defined in claim 14 wherein said motor is drivingly connected to said impellers by a drive belt.

Claims

1. A combination sump and pump assembly for a dishwasher including a container means defining a washing chamber and having a bottom wall with a generalLy central opening therein, the combination comprising: first housing means effectively fixed to said bottom wall generally aligned with and depending from said opening for defining a sump chamber disposed generally below and in fluid communication with said washing chamber; generally annular fine mesh filter means disposed in said sump chamber and forming a first sump portion from said filter means and a second sump portion downstream from said filter means; a cover attached to said first housing means separating said second sump portion from said washing chamber and defining a fluid strainer between said washing chamber and said first sump portion; fluid distribution means including means within said sump chamber for defining a fluid distribution conduit extending upwardly therethrough; second housing means defining a recirculation pump cavity disposed generally below said first housing means and having an inlet in fluid communication with said second sump portion and an outlet in fluid communication with said fluid distribution conduit; third housing means disposed generally below said first housing means and defining a drain pump cavity having an inlet in fluid communication with said first sump portion and an outlet in fluid communication with an external drain; a first impeller operable in said recirculation pump cavity for effecting flow of fluid from said first sump portion through said filter means and said second sump portion into said recirculation pump cavity for pumping to said fluid distribution conduit; a second impeller operable in said drain pump cavity for effecting flow of fluid and particles therein from said first sump portion to said drain pump cavity and to said external drain; and means for supporting said first and second impellers for rotation within said pump cavities.

3. A combination sump and pump assembly for a dishwasher as defined in claim 1 wherein said fluid distribution conduit extends generally upwardly through said second sump portion and through said cover for conduction of fluid from said recirculation pump cavity to said washing chamber.

7. A combination sump and pump assembly for a dishwasher as defined in claim 5 wherein said housing means defines a fluid conductor from said first sump portion to the inlet of said drain pump cavity.

8. A combination sump and pump assembly for a dishwasher as defined in claim 5 wherein said imperforate cover, said housing means and said fine mesh filter means are generally concentric to the axis of rotation of said recirculation pump impeller and said drain pump impeller.

10. A dishwasher comprising: container means defining a washing chamber and including a bottom wall having a generally central opening therein; housing means effectively fixed to said bottom wall and generally aligned with and depending from said opening for defining a sump chamber disposed generally below and in fluid communication with said washing chamber; generally annular fine mesh filter means disposed within said sump chamber and forming a first sump portion upstream from said filter means and a second sump portion downstream from said filter means; fluid distribution means including means within said second pump portion for defining a fluid distribution conduit extending upwardly therethrough; a generally annular imperforate cover attached to said housing means aligned with said central opening for accommodating said fluid distribution conduit and being disposed for separating said second pump portion from said washing chamber and for defining a fluid strainer between said washing chamber and said first sump portion; a recirculation pump cavity defined by said housing means and having an inlet in fluid communication with said second sump portion and an outlet in fluid communication with said fluid distribution conduit; a drain pump cavity defined by said housing means and having an inlet in fluid communication with said first sump portion and an outlet in fluid communication with an external drain; a first impeller operable in said recirculation pump cavity for effecting flow of fluid from said sump portion through said filter means and said second sump portion into said recirculation pump cavity for pumping to said fluid distribution conduit, said fluid distribution means including means including rotatable recirculation means mounted on and in fluid communication with said fluid distribution conduit and operable for spraying into said washing chamber for removing particles from articles contained therein; auxiliary spray means mounted on and in fluid communication with said fluid distribution conduit and disposed within said second cavity portion for flushing filtered particles from said fine mesh filter means; a second impeller operable in said drain pump cavity for effecting flow of fluid and particles therein from said first sump portion to said drain pump cavity for pumping to said external drain; And means for operating said first and second impellers.

11. A dishwasher as defined in claim 10 wherein a drain conduit between said first sump portion and the inlet of said drain pump cavity is defined by said housing means.

14. A dishwasher comprising: container means defining a washing chamber and including a bottom wall having a generally central opening therein; structural support means connected to said container means for support thereof on a generally horizontal surface; fluid recirculation means for effecting a washing of articles in said washing chamber; housing means effectively fixed to said bottom wall and generally aligned with and depending from said opening for defining a sump chamber disposed generally below and in fluid communication with said washing chamber; generally annular fine mesh filter means disposed within said sump chamber and forming a first sump portion upstream from said filter means and a second sump portion downstream from said filter means; an imperforate cover attached to said housing means generally aligned with said central opening and being disposed for separating said second sump portion from said washing chamber and for defining a fluid strainer between said washing chamber and said first sump portion; a recirculation pump cavity defined by said housing means and having an inlet in fluid communication with said second sump portion and an outlet in fluid communication with said fluid recirculation means; a drain pump cavity defined by said housing means and having an inlet in fluid communication with said fluid sump portion and an outlet in fluid communication with an external drain; a first impeller operable in said recirculation pump cavity for effecting flow of fluid from said sump portion through said filter means and said second sump portion into said recirculation pump cavity for pumping to said fluid recirculation means, said fluid recirculation means being operable for spraying fluids into said washing chamber to remove particles from articles contained therein and for spraying fluids onto said fine mesh filter means to flush filtered particles therefrom into said first sump portion; a second impeller operable in said drain pump cavity for effecting flow of fluid and particles therein from said first sump portion to said drain pump cavity for pumping to said external drain; means depending from said housing means for rotatively supporting said impellers; and pump drive means including a motor having an axis of operation parallel to the axis of operation of said recirculation and drain pump impellers and spaced laterally therefrom.