Convertible dishwasher

Abstract

A dishwasher includes a filtration system that can be configured in a chopping or filtration only arrangement. A check valve cover attached to an accumulator is inserted into a main intake of a sump and divides the main intake into a fluid recirculation chamber in communication with a recirculation intake port, and a separate fluid draining chamber in communication with a drain port. When a drain pump is actuated, fluid is pulled from the accumulator through the drain port until pressure within the fluid draining chamber drops below the pressure of the sump and a check valve in the check valve cover is forced open, allowing fluid to be channeled out of the fluid recirculation chamber into the fluid draining chamber. Optionally, a fine filter system can replace the convertible filtration system, whereby the main intake is in fluid communication with both the recirculation intake port and the drain port.

Claims

1. A dishwasher having a filtration system comprising: a tub defining a washing chamber; at least one spray device mounted in the washing chamber; a sump unit within the washing chamber including a recessed main intake defined, at least in part, by a side wall and having a recirculation intake port and a drain port; an accumulator; a drain check cover fluidly connected to the accumulator and removably disposed in the recessed main intake wherein, with the drain check cover disposed in the recessed main intake, the drain check cover divides the recessed main intake into a fluid recirculation chamber, to which the recirculation intake port is exposed, and a fluid draining chamber, to which the drain port is exposed, and, with the drain check cover not disposed in the recessed main intake, the recessed main intake is not divided into the fluid recirculation chamber and the fluid draining chamber, and the recirculation intake port and the drain port are both exposed to the recessed main intake; and a recirculation pump connected to the recirculation intake port and fluidly interposed between the sump unit and each of the at least one spray device and the accumulator, wherein the dishwasher is configured so that, during operation of the dishwasher, the recirculation pump causes fluid to flow through the at least one spray device whether or not the drain check cover is disposed in the recessed main intake.

2. The dishwasher according to claim 1, wherein the drain check cover includes a tubular portion spaced radially inward from the side wall within the recessed main intake.

3. The dishwasher according to claim 1, wherein the drain check cover includes a lower portion sealing the fluid recirculation chamber from the fluid draining chamber, between the recirculation intake port and the drain port.

4. The dishwasher according to claim 3, wherein the drain check cover further comprises a check valve selectively sealing a fluid inlet providing fluid communication between the fluid recirculation chamber and the fluid draining chamber.

5. The dishwasher according to claim 3, wherein the fluid draining chamber is defined within the recessed main intake below the drain check cover.

6. The dishwasher according to claim 3, wherein the recessed main intake is provided with an internal ledge, said lower portion being seated upon the internal ledge.

7. The dishwasher according to claim 1, further comprising: a drain pump connected to the drain port; and a chopper assembly provided in combination with the recirculation pump.

8. The dishwasher according to claim 1, further comprising: a fine filter located within the recessed main intake between the side wall and the drain check cover to filter fluid entering the recessed main intake.

9. The dishwasher according to claim 8, wherein the fine filter is secured to the drain check cover.

10. The dishwasher according to claim 8, wherein the fine filter includes a central opening, and the drain check cover is received in the central opening of the fine filter.

11. The dishwasher according to claim 1, wherein the drain check cover is configured to be received in a central opening of a fine filter.

12. The dishwasher according to claim 1, wherein the drain check cover includes a filter receiving aperture configured to secure a fine filter to the drain check cover.

13. A method of operating a dishwasher including a tub defining a washing chamber, at least one spray device mounted in the washing chamber, a sump unit within the washing chamber including a recessed main intake defined, at least in part, by a side wall and having a recirculation intake port and a drain port, an accumulator, a drain check cover fluidly connected to the accumulator and removably disposed in the recessed main intake, and a recirculation pump connected to the recirculation intake port and fluidly interposed between the sump unit and each of the at least one spray device and the accumulator, wherein, with the drain check cover disposed in the recessed main intake, the drain check cover divides the recessed main intake into a fluid recirculation chamber, to which the recirculation intake port is exposed, and a fluid draining chamber, to which the drain port is exposed, and wherein, with the drain check cover not disposed in the recessed main intake, the recessed main intake is not divided into the fluid recirculation chamber and the fluid draining chamber, and the recirculation intake port and the drain port are both exposed to the recessed main intake, the method comprising: directing washing fluid into the fluid recirculation chamber; operating the recirculation pump to draw the washing fluid from the recirculation intake port; directing the washing fluid from the recirculation pump to both the at least one spray device and the accumulator, wherein the recirculation pump causes fluid to flow through the at least one spray device whether or not the drain check cover is disposed in the recessed main intake; collecting particulates from the washing fluid flowing through the accumulator; and operating a drain pump to draw washing fluid and the particulates from the accumulator to the fluid draining chamber through the drain check cover.

14. The method of claim 13, further comprising: filtering the washing fluid entering the recessed main intake of the sump unit from the washing chamber.

15. The method of claim 13, further comprising: pivoting a check valve to unblock a fluid inlet connecting the fluid recirculation chamber and the fluid draining chamber upon operating the drain pump.

16. The method of claim 13, further comprising: chopping particulates entrained in the washing fluid upon operating the recirculation pump.

17. The method of claim 16, further comprising: fine filtering the washing fluid within the recessed main intake prior to directing the washing fluid from the recirculation pump to both the at least one spray device mounted in the washing chamber and the accumulator.

18. The method of claim 13, further comprising, upon operating the drain pump, initially causing the particulates to be drained from the accumulator and fluid draining chamber, followed by washing fluid being drained from the fluid recirculation chamber.

19. A dishwasher having a filtration system comprising: a tub defining a washing chamber; at least one spray device mounted in the washing chamber; a sump unit within the washing chamber including a recessed main intake defined, at least in part, by a side wall and having a recirculation intake port and a drain port, wherein the recirculation intake port and the drain port are formed in the side wall of the recessed main intake; an accumulator; a drain check cover fluidly connected to the accumulator and removably disposed in the recessed main intake wherein, with the drain check cover is disposed in the recessed main intake, the drain check cover divides the recessed main intake into a fluid recirculation chamber, to which the recirculation intake port is exposed, and a fluid draining chamber, to which the drain port is exposed, and, with the drain check cover is not disposed in the recessed main intake, the recessed main intake is not divided into the fluid recirculation chamber and the fluid draining chamber, and the recirculation intake port and the drain port are both exposed to the recessed main intake; and a recirculation pump connected to the recirculation intake port and fluidly interposed between the sump unit and each of the at least one spray device and the accumulator.

20. The dishwasher according to claim 19, wherein the recirculation intake port is located such that fluid flowing through the recirculation intake port exits the recessed main intake in an outward direction relative to a center of the recessed main intake.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a partial perspective view of a dishwasher constructed in accordance with a known dishwasher arrangement;

(2) FIG. 2 is a partial exploded view of a water distribution and filtration system of the dishwasher of FIG. 1;

(3) FIG. 3 is an upper perspective view of the known removable filtration system of FIG. 2;

(4) FIG. 4 is a perspective view of a dishwasher constructed in accordance with the present invention;

(5) FIG. 5 is a partial exploded view of the dishwasher of FIG. 4;

(6) FIG. 6 is a partial cross-sectional view of a portion of the dishwasher of FIG. 4;

(7) FIG. 7 is a further cross-sectional view of the water distribution and filtration system of the invention; and

(8) FIG. 8 is a partial cross-sectional view of a check valve cover incorporated in the water distribution and filtration system of FIG. 7.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(9) With initial reference to FIG. 4, a dishwasher 200 is shown including a convertible filtration system 202 constructed in accordance with the present invention. Filtration system 202 is adapted to be utilized in a chopping type dishwasher arrangement or in a filtration only dishwasher arrangement, as will be discussed in more detail below. Certain structure of dishwasher 200 is the same or substantially the same as that of dishwasher 2 of FIG. 1, such that like reference numbers correspond to identical parts. Conduit 57 and spray manifold assembly 59 are not shown for the sake of simplicity, but it should be understood that various water distribution arrangements could be utilized.

(10) Details of filtration system 202 of the present invention will now be discussed with reference to FIG. 5. In the embodiment shown, central main strainer 36 includes a main body portion 100 having an aperture 105 and a central opening 112. It should be understood that the central main strainer of the present invention can take many different forms depending on the type of water distribution systems utilized within dishwasher 200. For example, if dishwasher 200 where constructed to include a conduit 57 and spray manifold assembly 59 (shown in FIG. 1), then the central main strainer can be in the form of central main strainer 36 depicted in FIGS. 1 and 2. Regardless of the particular configuration, when assembled, central opening 112 of central main strainer 36 fits over distribution manifold 53 such that a fluid supply hub 206 for attachment of spray arm 55, and an auxiliary port 208 for attachment to another fluid conduit (not shown) extend through central opening 112. Filtration system 202 further includes an accumulator 204 which attaches to a check valve cover 210 via a funnel portion 211 of accumulator 204. When assembled, check valve cover 210 and funnel portion 211 extend through aperture 105 into recessed main intake 73. Preferably, check valve cover 210 is simply seated in recessed main intake 73, but could be secured in position, such as through the use of a clasp arrangement employed to lock the fine strainer 39 in place in the prior art referenced above. An optional fine filter 212, which can also be inserted into recessed main intake 73, is provided for use in further filtering washing fluid as will be discussed in more detail below. In general, fine filter 212 is comprised of a substantially circular fine filter screen having a bottom wall 212a and a top wall 212b defining a central opening there through.

(11) Details regarding the function of filtration system 202 will now be discussed with reference to FIG. 6. In a manner known in the art, during a washing cycle initiated by a user, washing fluid pumped by a recirculation pump 213 (depicted in FIG. 7) forces washing fluid up through fluid supply hub 206 to attached spray arm 55 (shown in FIG. 5), which sprays washing fluid within washing chamber 14. Washing fluid may also supply another spray arm or manifold, such as spray arm assembly 59 depicted in FIG. 1, through auxiliary port 208. A bypass port 214 extends from a main conduit 216 connected to fluid supply hub 206 and is friction fit to an inlet port 218 of an accumulator filter chamber 220 such that a small percentage of the fluid flowing from recirculation pump 213 is directed into accumulator 204. In the embodiment shown, inlet port 218 has an initial diameter which is wider than the diameter of bypass port 214, but narrows before linking to accumulator filter chamber 220, thereby forming a pressure relief venturi portion 221.

(12) With this arrangement, during the dishwashing cycle, a portion of washing fluid directed toward fluid supply hub 206 is diverted through bypass port 214 to accumulator filter chamber 220, with the majority of the washing fluid being forced out of filter chamber 220 and back into washing chamber 14 through a fine filter screen 222. Although depicted with a reinforcing member 223 extending up within accumulator filter chamber 220, accumulator filter chamber 220 is preferably defined by a single chamber. In any case, particles of food entrained in the washing fluid are filtered out of the washing fluid exiting through fine filter screen 222 into tub 5, with the particles collecting in filter chamber 220. In the preferred embodiment shown, fine filter screen 222 is in the form of a cover plate having outer flange portions 224 adapted to snap onto or otherwise engage a mounting portion 226 of accumulator 204. Fine filter screen 222 is positioned such that lower nozzles (not shown) on wash arm 55 direct fluid onto fine filter screen 222 to clean accumulated particles off of fine filter screen 222 during a washing cycle.

(13) The manner in which washing fluid is channeled to a drainage pump 230 and recirculation pump 213 will now be discussed with reference to FIG. 7. In a first embodiment, filtration system 202 is utilized in a chopping type dishwashing arrangement. In use, washing fluid flowing into sump unit 50 during the dishwashing cycle will flow by gravity through central main strainer 36 into recessed main intake 73. Central main strainer 36 acts as a coarse particle strainer to prevent coarse particles from entering recessed main intake 73. However, washing fluid flowing into recessed main intake 73 may carry fine particles which are carried with the washing fluid into recirculation intake port 80 to a recirculation pump inlet generally indicated at 232 and to a chopper assembly 233. In a manner known in the art, chopper assembly 233 macerates particles entrained within washing fluid to be recirculated to fluid supply hub 206 by recirculation pump 213. Various types of chopping mechanisms are known in the art which could be utilized in conjunction with the present invention. See, for example, U.S. Pat. Nos. 7,146,992 and 7,404,864 which are incorporated herein by reference. In one particular preferred embodiment, the chopper assembly 233 is constructed by a blade rotating on a perforated metal disc, with the perforations being very small, such as in the order of 1-1.2 mm in diameter. In this way, particles flowing into wash arm 55 from fluid distribution manifold 53 are small enough such that they do not clog wash arm 55 or otherwise interfere with the distribution of washing liquid into tub 5.

(14) Washing fluid within filter chamber 220 of accumulator 204 carries fine particles collected in filter chamber 220 to funnel portion 211 and into a bottom portion 236 of main intake 73 through drain check cover 210. In a preferred embodiment, a tubular inlet portion 242 of drain check cover 210 frictionally fits about a tubular outlet 244 of funnel portion 211 to removably connect drain check cover 210 to accumulator 204. Funnel portion 211 and tubular inlet portion 242 of drain check cover 210 are arranged radially inward from an upper side wall 245 of main intake 73 such that the presence of accumulator 204 does not significantly impact the fluid capacity of main intake 73. Drain check cover 210 further includes a mounting flange 246 that extends about the periphery of a bottom mounting portion 248 and seals against a ledge 250 extending about the periphery of the bottom portion 236 of main intake 73. With this configuration, drain check over 210 is fluidly connected to accumulator 204, while being disposed in and dividing main intake 73 into an upper fluid recirculating chamber 254 in fluid communication with recirculation pump 213, and a separate, bottom fluid draining chamber 255 in communication with drain pump 230 through a drain port 256.

(15) As best seen in FIG. 8, drain check cover 210 includes a check valve 260 attached to an inner wall 262, with check valve 260 functioning to seal a fluid inlet 264 adjacent a trough 266 when in an un-actuated or sealing position. With this arrangement, when drain pump 230 is actuated, washing fluid, and any entrained particles therein, are pulled from accumulator 204 before washing fluid is pulled from sump unit 50. More specifically, washing fluid and accumulated particles are pulled from accumulator 204 through drain port 256 until pressure within fluid draining chamber 255 drops below the pressure of sump unit 50. The low pressure forces check valve 264 open, allowing fluids from sump unit 50 to be channeled by trough 266 out of fluid recirculation chamber 254, through fluid inlet 264, and into fluid draining chamber 255. Washing fluid exiting fluid draining chamber 255 via drain port 256 is discharged from dishwasher 200 in a manner known in the art.

(16) In a second embodiment, filtration system 202 is utilized in a filtration only dishwashing arrangement. More specifically, when a filtration with accumulator only dishwashing arrangement is desired, accumulator 204 and check valve cover 210 are inserted into recessed main intake 73 in the manner described above, followed by, or as part of, fine filter 212. See FIG. 7. Preferably, bottom wall 212a of fine filter 212 mounts or is otherwise secured to check valve cover 210, and top wall 212b of fine filter 212 extends to accumulator 204 or up to filter screen 36, such that fluid entering upper fluid recirculation chamber 254 from tub 5 is filtered by fine filter 212 before entering recirculation pump inlet 232. In the embodiment shown in FIG. 7, bottom wall 212a of fine filter 212 fits within a filter receiving aperture 257 within check valve cover 210 to secure fine filter 212 to check valve cover 210. However, fine filter 212 could also be made part of check valve cover 210. Preferably, accumulator 204 is configured for easy removal from sump unit 50 such that fine filter 212 can be accessed by a user for cleaning. When drain pump 230 is actuated, washing fluid, along with any entrained particles therein, are pulled from accumulator 204 before washing fluid is pulled from sump unit 50. More specifically, washing fluid is pulled from accumulator 204 through drain port 256 until pressure within fluid draining chamber 255 drops below the pressure of sump unit 50. The low pressure forces check valve 264 open, allowing fluids from fluid recirculation chamber 254 to be channeled through fluid inlet 264, and into fluid draining chamber 255. Again, washing fluid exiting fluid draining chamber 255 via drain port 256 is discharged from dishwasher 200 in a manner known in the art.

(17) At this point, it should be recognized that a feature of the present invention is the advantageous convertible nature of dishwasher 200. That is, sump unit 50 establishes a universal sump unit configured to be utilized with the convertible filtration system 202 described above, as well as with a non-chopping or fine filter system wherein a main intake filter, such as fine filter 39 of FIGS. 1 and 2, is utilized. More specifically, during assembly of dishwasher 200, a manufacturer can select between the convertible filtration system 202 described above and the fine filtration system utilizing fine strainer 39. When the fine filtration system is selected, fine filter 39 is inserted into recessed main intake 73 and performs the function of filtering washing fluid flowing into recessed main intake 73 from tub 5 in a manner known in the art. However, when universal sump unit 50 is utilized with check valve cover 210, a closed system is created, separate from the sump, where soils can be accumulated during the washing of dishes. Specifically, drain check cover 210 divides recessed main intake 73 into fluid recirculation chamber 254 in communication with recirculation intake port 80 and separate draining chamber 255 in communication with drain port 256, and when universal sump unit 50 is utilized with the fine filtration system, recessed main intake 73 is simultaneously in communication with both recirculation intake port 80 and drain port 256.

(18) Advantageously, the present invention allows for a single dishwasher tub and sump arrangement to be readily adapted for use with either a chopping type filtration system or a non-chopping filtration system. Thus, a manufacturer or user can select the type of system to be used based on each system's advantages/disadvantages and the particular desires or needs of the user. For example, the chopping type filtration arrangement is self-cleaning and relatively maintenance free, while the non-chopping filtration arrangement can utilize a smaller pump motor and is generally quieter than the chopping type filtration arrangement. Additionally, when utilized, accumulator 204 reduces the amount of soil re-deposited on dishes. The wash water is therefore cleaner and can be used longer, requiring less water to clean the dishes. Further, accumulator 204 is positioned such that backwash nozzles (not shown) used to clean accumulator filter screen 222 are the same nozzles used to clean main filter screen 36 when accumulator 204 is not utilized. Thus, manufacturing costs are reduced by providing dishwasher parts that can be utilized in conjunction with the different filtration arrangements discussed above.

(19) Although described with reference to preferred embodiments of the invention, it should be readily understood that various changes and/or modifications can be made to the invention without departing from the spirit thereof. For instance, although dishwasher 200 is depicted with only a single spray arm 55, it should be understood that dishwasher 200 can include an upper spray arm and even additional spray arms or other fluid distribution systems desired. In fact, the invention can be employed in a dishwasher having a wide range of spray devices, including rotatable spray arms, spray discs, fixed heads and the like. Additionally, when non-chopping filtration is desired, the drain check cover and accumulator arrangement of the invention could be used with filter arrangements other than filter 222. In general, the invention is only intended to be limited by the scope of the following claims.