U.S. patent application number 12/191476 was filed with the patent office on 2010-02-18 for removable dishwasher filtration system.
This patent application is currently assigned to WHIRLPOOL CORPORATION. Invention is credited to GEOFFREY L. DINGLER, MARC R. PENDERGRASS, DEMETRIUS JEROME SCHAAF, CHAD THOMAS VANDERROEST.
Application Number | 20100037923 12/191476 |
Document ID | / |
Family ID | 41680407 |
Filed Date | 2010-02-18 |
United States Patent
Application |
20100037923 |
Kind Code |
A1 |
DINGLER; GEOFFREY L. ; et
al. |
February 18, 2010 |
REMOVABLE DISHWASHER FILTRATION SYSTEM
Abstract
A dishwasher having a removable filtration system includes a
main coarse filter screen having a central opening for removably
fitting the filter screen around a water distribution manifold. The
filter screen includes an outer circumferential rim portion have an
elastomeric seal over-molded thereto which is press-fit into a
channel in a lower sump unit such that the filter screen is
suspended over a sump enclosure. A finer, secondary strainer
extends through the filter screen and provides secondary filtering
of washing fluid entering the sump enclosure through the filter
screen. Preferably, the filtration system also includes a
non-removable or backup strainer which provides coarse straining of
washing fluid should a user fail to properly reinstall the
removable filter screen and/or the secondary strainer.
Inventors: |
DINGLER; GEOFFREY L.; (SAINT
JOSEPH, MI) ; PENDERGRASS; MARC R.; (EVANSVILLE,
IN) ; SCHAAF; DEMETRIUS JEROME; (SAINT JOSEPH,
MI) ; VANDERROEST; CHAD THOMAS; (COVERT, MI) |
Correspondence
Address: |
WHIRLPOOL PATENTS COMPANY - MD 0750
500 RENAISSANCE DRIVE - SUITE 102
ST. JOSEPH
MI
49085
US
|
Assignee: |
WHIRLPOOL CORPORATION
BENTON HARBOR
MI
|
Family ID: |
41680407 |
Appl. No.: |
12/191476 |
Filed: |
August 14, 2008 |
Current U.S.
Class: |
134/104.4 ;
29/428 |
Current CPC
Class: |
A47L 15/4204 20130101;
Y10T 29/49826 20150115 |
Class at
Publication: |
134/104.4 ;
29/428 |
International
Class: |
A47L 15/42 20060101
A47L015/42 |
Claims
1. A dishwasher having a removable dishwasher filtration system
comprising: a tub defining a washing chamber; a water distribution
manifold in communication with at least one spray arm; a sump unit
within the washing chamber including a support surface having a
bottom wall and a side wall defining a channel; a filter screen
having a main body portion including an aperture therein and an
outer rim portion having an integrated elastomeric seal positioned
in the channel in sealed engagement with the support surface such
that the filter screen is held suspended by the engagement of the
outer rim portion with the support surface, wherein the filter
screen is adapted to filter debris from wash liquid entering the
sump unit from the tub; and a secondary strainer extending into the
aperture in the screen and being readily removable therefrom for
cleaning purposes, the secondary strainer being adapted to remove
debris from wash liquid passing the filter screen and flowing
through the sump unit.
2. The dishwasher according to claim 1, wherein the filter screen
is substantially circular and includes first and second arm
portions which define a central opening through which the water
distribution manifold extends.
3. The dishwasher according to claim 2, wherein the first and
second arm portions form a slot which leads to the central
opening.
4. The dishwasher according to claim 1, wherein the elastomeric
seal is constituted by an over-molded rubber seal.
5. The dishwasher according to claim 4, wherein the outer rim
portion of the filter screen includes a downwardly turned flange
about which the elastomeric seal is over-molded.
6. The dishwasher according to claim 5, wherein the downwardly
turned flange curves radially inwardly.
7. The dishwasher according to claim 5, wherein the downwardly
turned flange and the elastomeric seal are flexible, with the outer
rim portion being press-fit into the channel, thereby preventing
debris from bypassing the filter screen.
8. The dishwasher according to claim 1, wherein the elastomeric
seal includes a top wall portion which is substantially flush with
a top wall portion of the sump unit when the outer rim portion is
mounted in the channel.
9. The dishwasher according to claim 8, wherein the elastomeric
seal further includes a bottom wall portion and both inner and
outer side wall portions.
10. The dishwasher according to claim 9, wherein the channel is
further defined by another side wall which is spaced radially from
the side wall, said elastomeric seal being slightly compressed
between the side wall and the another side wall within the channel
to retain the filter screen in place.
11. The dishwasher according to claim 1, wherein the filter screen
is flexible.
12. The dishwasher according to claim 11, wherein the filter screen
is readily removable from the sump unit for cleaning purposes.
13. The dishwasher according to claim 1, wherein the sump unit
comprises a recessed main intake including an outlet, said
secondary strainer extending into the main intake.
14. The dishwasher according to claim 13, further comprising: a
non-removable strainer mounted directly adjacent the outlet of the
main intake, wherein the non-removable strainer is adapted to
prevent coarse debris from entering the outlet.
15. The dishwasher according to claim 1, wherein the filter screen
comprises a dam portion which channels fluid toward the secondary
strainer.
16. A method of assembling a filtration system in a dishwasher
having a tub defining a washing chamber and a sump unit below the
washing chamber comprising: mounting a filter screen within the
washing chamber by positioning an elastomeric seal provided on an
outer rim portion of the filter screen in sealing engagement with
support surfaces which define a channel of the sump unit; and
fitting a removable secondary strainer into an aperture provided in
the filter screen, with the removable secondary strainer extending
into a recessed main intake portion of the sump unit to remove
debris from wash liquid passing the filter screen and flowing
through the sump unit.
17. The method of claim 16, wherein mounting the filter screen
constitutes press-fitting a flexible outer rim portion of the
filter screen, about which the elastomeric seal is over-molded,
into the channel.
18. The method of claim 17, wherein the elastomeric seal is
compressed within the channel.
19. The method of claim 16 wherein, upon mounting the filter
screen, a water distribution manifold extends into a central
aperture formed in the filter screen.
20. The method of claim 16, further comprising: fitting a
non-removable strainer directly adjacent an outlet of the main
intake portion to prevent coarse debris from entering the outlet.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention pertains to the art of dishwashers
and, more specifically, to a dishwasher including a removable
filtration system.
[0003] 2. Description of the Related Art
[0004] Dishwashers for use in the home typically have a filter
arrangement to filter material from wash liquid circulating in the
dishwasher to prevent such material from re-depositing on dishware
being washed. Many dishwashers have at least one filter interposed
between a tub sump and the circulation pump for the dishwasher.
Some dishwashers are known to have a bypass filter arrangement,
such as a flow-through filtration system, independent of the
circulation pump, to filter wash liquid upstream of the circulation
pump. Flow-through filtration wash systems require periodic removal
of filter screens for cleaning by a consumer. Consumers are
expected to remove, clean and properly reinstall filter components
on a regular basis. However, problems may occur when a consumer
fails to replace the filters properly before a new wash cycle. For
example, dishwasher spray nozzles may become plugged with debris,
causing significant performance degradation and potentially
requiring professional repair of the machine. Additionally, debris
may collect around the rim of a removable filter screen or may even
bypass the filter screen if a proper seal is not maintained between
the filter screen and its support base. Again, performance of the
dishwasher may be degraded by such debris entering the pump and
distribution systems of the dishwasher.
[0005] With the above in mind, there exists the need for an
inexpensive and easy-to-use dishwasher filtration system that
provides further protection against damage from debris entering the
dishwasher's pump and distribution system.
SUMMARY OF THE INVENTION
[0006] The present invention is directed to a dishwasher having a
removable filtration system. In general, the removable filtration
system includes a main coarse filter screen having a central
opening for removably fitting the filter screen around a water
distribution manifold. The filter screen includes an outer
circumferential edge have an elastomeric, over-molded seal which
can be press-fit into a channel in a lower sump unit such that the
filter screen is suspended over a sump enclosure. When installed, a
top wall of the over-molded seal is substantially flush with a top
wall of the sump unit, thus preventing debris from bypassing the
filter screen or accumulating around the peripheral edge of the
filter screen. The filter screen further includes an aperture
through which a secondary strainer extends into the sump enclosure.
The secondary strainer provides finer filtering of washing fluid
entering the sump enclosure through the filter screen, as well as
providing a course screen for over-flow protection. Preferably, the
filtration system also includes a non-removable or backup strainer
which provides coarse straining of washing fluid should a user fail
to properly reinstall the removable filter screen and/or secondary
strainer, or should one of the filter screen or strainer become
damaged.
[0007] Additional objects, features and advantages of the present
invention will become more readily apparent from the following
detailed description of a preferred embodiment when taken in
conjunction with the drawings wherein like reference numerals refer
to corresponding parts in the several views.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a partial perspective view of a dishwasher
constructed in accordance with the present invention, with a door
of the dishwasher being open;
[0009] FIG. 2 is a partial perspective view of a water distribution
and filtration system of the dishwasher of FIG. 1;
[0010] FIG. 3 is a partial exploded view of the removable
filtration system of the present invention;
[0011] FIG. 4 is a partial cross-sectional view of a removable
filter screen of the present invention;
[0012] FIG. 5 is a top perspective view of a sump system of the
dishwasher of FIG. 1;
[0013] FIG. 6 is a top perspective view of the sump system of FIG.
5 including a non-removable filter of the present invention;
and
[0014] FIG. 7 is a perspective view of the non-removable filter of
FIG. 6.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0015] With initial reference to FIGS. 1 and 2, a dishwasher
constructed in accordance with the present invention as generally
indicated at 2. As shown, dishwasher 2 includes a tub 5 which is
preferably molded of plastic so as to include integral bottom,
side, and rear walls 8-11 respectively, as well as a top wall (not
shown). Tub 5 defines a washing chamber 14 within which soiled
kitchenware is adapted to be placed upon shiftable upper and lower
racks (not shown), with the kitchenware being cleaned during a
washing operation in a manner widely known in the art. Tub 5 has
attached thereto a pivotally supported door 20 used to seal chamber
14 during the washing operation. In connection with the washing
operation, door 20 is preferably provided with a detergent tray
assembly 23 within which a consumer can place liquid or particulate
washing detergent for dispensing at predetermined portions of the
washing operation. Of course, dispensing detergent in this fashion
is known in the art such that this arrangement is only being
described for the sake of completeness.
[0016] Disposed within tub 5 is a filtration system generally
indicated at 30. In the preferred embodiment, filtration system 30
includes a central main strainer or filter screen 36 and a
secondary, fine strainer 39. Extending about a substantial portion
of filtration system 30, at a position raised above bottom wall 8,
is a heating element 44. In a manner known in the art, heating
element 44 preferably takes the form of a sheath, electric
resistance-type heating element.
[0017] Dishwasher 2 further includes a circulation pump (not shown)
adapted to direct washing fluid from a sump unit 50 (best seen in
FIGS. 5 and 6) to a water distribution manifold indicated at 53. In
a manner known in the art, water distribution manifold 53 supplies
washing fluid to at least a lower wash arm 55 and a conduit 57
leading to an upper spray arm (not shown). Additionally, water
distribution manifold 53 may be in fluid communication with a spray
manifold assembly 59 including a plurality of spray discs 62. The
manner in which wash arm 54 and spray manifold assembly 59 are
utilized is known in the art, such that this structure will not be
described further herein.
[0018] Details of sump unit 50 utilized in dishwasher 2 are
depicted in FIGS. 3-6. Sump unit 50 generally comprises a sump
enclosure 68 with filter screen 36 preferably disposed over a top
opening of enclosure 68, and a recessed main intake 73 having an
outlet 80 leading to a circulation pump (not shown) for circulating
fluid through water distribution manifold 53 to wash arm 55,
conduit 57 and manifold assembly 59. In accordance with the present
invention, a filter support surface 83 extends around the upper
perimeter of sump enclosure 68. Filter 36 is supported along its
outer circumferential edge 90 by filter support surface 83 and
seals against filter support surface 83 in a manner more fully
discussed below.
[0019] Filter screen 36 is substantially circular and includes a
main body portion 100 have an aperture 105 there through, and arm
portions 108 and 109 which define a central opening 112 in the form
of a slot there between. As depicted best in FIG. 3, central
opening 112 of filter screen 36 fits around water distribution
manifold 53. Filter screen 36 preferably constitutes a first-pass
coarse screen having a shape that aids in channeling wash liquid.
More specifically, filter screen 36 includes a dam portion
indicated at 123 which aids in channeling a flow of washing fluid
across filter screen 36 to secondary strainer 39. Additionally,
filter screen 36 is oriented with respect to sump unit 50 such that
outer circumferential edge 90 is at a greater height than an inner
filter edge 126 of aperture 105. The resulting downwardly sloping
configuration of filter screen 36 facilitates the flow of washing
fluid to sump unit 50 and the distribution of food particles or
debris across filter screen 36.
[0020] As depicted in FIG. 4, outer circumferential edge 90 of
filter screen 36 comprises an inwardly curved flange portion 130
that basically establishes an open loop. An annular elastomeric
seal 133 extends about substantially the entire outer surface of
flange portion 130, with seal 133 including a bottom wall 136, a
side wall 137 and a top wall portion 138. In the preferred
embodiment of the present invention, seal 133 is constituted by an
over-molded flexible rubber seal. Support surface 83 is generally
defined by a bottom wall portion 140 extending laterally from a
sidewall 143 of sump unit 50, and an upstanding wall portion 146
extending vertically from bottom wall portion 140. Together, bottom
wall portion 140 and side wall 143 define a channel 150 into which
outer circumferential edge 90 of filter screen 36 can be inserted.
Preferably, channel 150 is further defined by an upstanding side
wall portion 152 extending from side wall 143, with seal 133
directly abutting side wall portion 152.
[0021] Filter screen 36 is preferably somewhat flexible in nature,
allowing for some flexing of inwardly curved flange portion 130 and
the integrated seal 133. In use, arm portions 108 and 109 of filter
screen 36 are fit around water distribution manifold 53 and outer
circumferential edge 90 is press-fit into channel 150 such that
seal 133 fits snuggly within channel 150, i.e., directly abuts
bottom wall 136 and is slightly compressed between side walls 137
and 152, while top wall portion 138 of seal 133 is substantially
flush with a top wall portion 158 of sump unit 50. With this
configuration, food and debris will not be able to collect between
filter screen 36 and sump unit 50 at outer circumferential edge 90,
nor will food or debris be able to bypass filter screen 36 by
flowing around outer circumferential edge 90. Additionally,
over-molded seal 133 cannot be lost or improperly positioned with
respect to filter screen 36, allowing for quick and easy
installation of filter screen 36 within channel 150.
[0022] During normal operation, wash water flows through filter
screen 36 into sump enclosure 68 and larger food particles from
dishes or tableware disposed in dishwasher 2 collect on filter
screen 36. Wash fluid within enclosure 68 is further filtered by
secondary strainer 39 before exiting into main intake 73. In a
preferred embodiment, secondary strainer 39 includes a twist lock
feature wherein secondary strainer 39 includes flanges (not shown)
which engage sump enclosure 68 about the periphery of intake 73 to
selectively lock secondary strainer 39 in place. However, other
locking arrangements that accommodate the easy removal of secondary
strainer 29 could be employed. In any case, sump enclosure 68 is
sloped such that fluid therein is directed to a fine screen portion
162 of secondary strainer 39 before entering main intake 73.
Secondary strainer 39 also works as a main filter bypass should
wash fluid become backed-up within washing chamber 14. More
specifically, if wash fluid cannot flow sufficiently through filter
screen 36, the level of fluid within washing chamber 14 will rise
slightly to the height of inlets 166 located about the periphery of
secondary strainer 39. Wash fluid will then flow through inlets 166
through a coarse screen portion 168 of secondary strainer 39 and
into main intake 73. In a manner known in the art, wash fluid exits
main intake 73 through outlet 80 and is recirculated within
dishwasher 2 via a circulation pump (not shown). If filter screen
36 becomes plugged or blocked, a user may simply lift secondary
strainer 39 clear of filter screen 36 and remove filter screen 36
from dishwasher 2 for cleaning. Likewise, secondary strainer 39 may
be removed and cleaned by a user when desired and replaced for the
next wash cycle.
[0023] In the case where a user forgets or fails to return filter
screen 36 and/or secondary strainer 39 to their proper positions
within dishwasher 2, or in the case where either one or both of
filter screen 36 and secondary strainer 39 becomes damaged, washing
fluid flowing through intake 73 will still be filtered before
entering outlet 80 by a non-removable or back-up strainer 170,
depicted in FIGS. 6 and 7. Non-removable strainer 170 is preferably
permanently fixed, or at least designed such that a user cannot
easily remove strainer 170 from dishwasher 2 and is arcuate in
shape to conform to the arc around inlet 80. Optionally,
non-removable strainer 170 may be adapted to be retrofit within
intake 73. Preferably, non-removable strainer 170 includes a coarse
screen 173 adapted to prevent debris from entering outlet 80 that
would be potentially damaging to the fluid distribution system of
dishwasher 2.
[0024] Although described with reference to a preferred embodiment
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 depicted
as generally circular in shape, it should be understood that a
variety of screen shapes could be utilized with the present
invention. In general, the invention is only intended to be limited
by the scope of the following claims.
* * * * *