U.S. patent application number 14/048332 was filed with the patent office on 2015-04-09 for filter cleaner for a dishwashing appliance.
This patent application is currently assigned to General Electric Company. The applicant listed for this patent is General Electric Company. Invention is credited to Jing Shen Tang.
Application Number | 20150096599 14/048332 |
Document ID | / |
Family ID | 52775967 |
Filed Date | 2015-04-09 |
United States Patent
Application |
20150096599 |
Kind Code |
A1 |
Tang; Jing Shen |
April 9, 2015 |
FILTER CLEANER FOR A DISHWASHING APPLIANCE
Abstract
A cleaner is provided for a filter of a dishwashing appliance.
The filter cleaner rotates within the filter and uses nozzles to
remove particulates on the filter surface. Energy from fluid flow
caused by a pump is used to rotate the filter cleaner. The
particulates removed from the filter are pumped away for
disposal.
Inventors: |
Tang; Jing Shen;
(Louisville, KY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
General Electric Company |
Schenectady |
NY |
US |
|
|
Assignee: |
General Electric Company
Schenectady
NY
|
Family ID: |
52775967 |
Appl. No.: |
14/048332 |
Filed: |
October 8, 2013 |
Current U.S.
Class: |
134/104.1 |
Current CPC
Class: |
A47L 15/4208
20130101 |
Class at
Publication: |
134/104.1 |
International
Class: |
A47L 15/42 20060101
A47L015/42 |
Claims
1. A dishwashing appliance, comprising: a wash chamber; a filter
for the receipt of fluid that has circulated through the wash
chamber, the filter having a chamber defined by a
cylindrically-shaped interior surface through which the fluid flows
for filtering; a filter cleaner, comprising a base defining a fluid
outlet for the flow of fluid from the chamber of the filter; a
bearing supported upon the base; a rotatable body positioned within
the chamber of the filter and rotatably supported by the bearing,
the rotatable body defining an interior channel for fluid flow that
is in fluid communication with the fluid outlet of the base; and a
pair of arcuate-shaped arms positioned on opposing sides of the
rotatable body, each arm having a nozzle positioned at a distal end
of the arm and adjacent to the interior surface of the filter, the
nozzle defining an inlet for the receipt of fluid and particles
from the interior surface of the filter, each arm defining a fluid
pathway providing fluid communication between the inlet of the
nozzle and the interior channel of the rotatable body.
2. The dishwashing appliance of claim 1, wherein the base and the
rotatable body define a circular gap separating the base and the
rotatable body, the gap positioned upstream of the fluid outlet of
the base.
3. The dishwashing appliance of claim 1, wherein the fluid inlet of
each nozzle extends longitudinally along the interior surface of
the filter.
4. The dishwashing appliance of claim 1, wherein the rotatable body
is pivotable relative to the bearing.
5. The dishwashing appliance of claim 1, wherein the rotatable body
defines a seat into which the bearing is removably received.
6. The dishwashing appliance of claim 1, wherein the rotatable body
defines a top portion and a bottom portion along a vertical
direction, and wherein a seat is positioned in the top portion.
7. The dishwashing appliance of claim 6, wherein the bearing
comprises a bearing support positioned over the fluid outlet of the
base and defining one more openings for the flow of fluid; and a
bearing shaft extending longitudinally towards the seat and having
a distal end received in the seat of the rotatable body.
8. The dishwashing appliance of claim 1, wherein the interior
surface of the filter defines an interior diameter, and wherein the
overall width of the rotatable body and the pair of arcuate-shaped
arms is less than the interior diameter of the filter so as to
define a gap between each nozzle and the interior surface of the
filter.
9. The dishwashing appliance of claim 1, wherein the fluid pathway
of each arm tapers along a direction from the rotatable body to the
nozzle.
10. The dishwashing appliance of claim 1, wherein each arm has a
cross-sectional shape within a plane that is perpendicular to the
flow of fluid along the fluid pathway, and wherein the
cross-sectional shape is substantially tear-drop.
11. The dishwashing appliance of claim 1, further comprising a
drain pump in fluid communication with the fluid outlet of the base
and configured to pull fluid through the fluid outlet so as to
cause the rotatable body and arms to rotate.
12. The dishwashing appliance of claim 1, wherein the inlets of the
nozzles are oriented so as to cause the rotatable body to rotate as
fluid is drawn through the fluid outlet of the base.
13. The dishwashing appliance of claim 1, further comprising a
wiping element positioned at the inlet to each nozzle and extending
between the nozzle and the interior surface of the filter so as to
wipe particles from the interior surface as the rotatable body is
caused to rotate.
14. The dishwashing appliance of claim 1, wherein the wash chamber
includes a sump portion defining a receptacle into which the filter
and filter cleaner are removably received.
15. The dishwashing appliance of claim 1, wherein the filter has a
filter top and a filter bottom relative to a vertical direction,
and wherein the filter top defines a fluid inlet for the receipt of
fluid into the chamber.
16. The dishwashing appliance of claim 1, wherein the wash chamber
comprises a sump portion defining a receptacle into which the
filter is received.
17. The dishwashing appliance of claim 1, wherein the wash chamber
comprises a sump portion having a grate.
18. The dishwashing appliance of claim 1, wherein the filter
comprises a plurality of filter media.
19. A dishwashing appliance, comprising: a wash chamber; a filter
for the receipt of fluid that has circulated through the wash
chamber, the filter having a chamber defined by a
cylindrically-shaped interior surface through which the fluid flows
for filtering; a filter cleaner, comprising a base defining a fluid
outlet for the flow of fluid from the chamber of the filter; a
bearing supported upon the base; a rotatable body positioned within
the chamber of the filter and rotatably supported by the bearing,
the rotatable body defining an interior channel for fluid flow that
is in fluid communication with the fluid outlet of the base; and at
least one arm positioned on the rotatable body, the arm having at
least one nozzle positioned along the arm and adjacent to the
interior surface of the filter, a bottom surface of the sump, or
both; the nozzle defining an inlet for the receipt of fluid and
particles from the interior surface of the filter, the at least one
arm defines a fluid pathway providing fluid communication between
the inlet of the nozzle and the interior channel of the rotatable
body.
Description
FIELD OF THE INVENTION
[0001] The subject matter of the present disclosure relates
generally to cleaning of a fluid filter used in a dishwashing
appliance.
BACKGROUND OF THE INVENTION
[0002] During wash and rinse cycles, dishwashers typically
circulate a fluid through a wash chamber over articles such as
pots, pans, silverware, and other cooking utensils. The fluid can
be e.g., various combinations of water and detergent during the
wash cycle or water (which may include additives) during the rinse
cycle. Typically the fluid is recirculated during a given cycle
using a pump. Fluid is collected at or near the bottom of the wash
chamber and pumped back into the chamber through e.g., nozzles in
the spray arms and other openings that direct the fluid against the
articles to be cleaned or rinsed. Fluids used in e.g., the wash or
rinse cycles may be heated. For example, hot water may be supplied
to the dishwasher and/or the dishwasher may include one or more
heat sources (e.g., electrically-resistant heating elements) for
heating fluids used in wash or rinse cycles and for providing heat
during a drying cycle.
[0003] Depending upon the level of soil upon the articles, fluids
used during wash and rinse cycles will become contaminated with
soils in the form of debris or particles that are carried with the
fluid. To protect the pump and remove some of the particles before
recirculating the fluid through the wash chamber, it is beneficial
to filter the fluid so that relatively clean fluid is applied to
the articles in the wash chamber and materials are removed or
reduced from the fluid supplied to the pump.
[0004] For mechanical filtration, the selectivity of the filter to
remove soil particles of different sizes is typically determined by
providing fluid paths (such as pores or apertures) through a filter
screen or filter media that are smaller than the particles for
which filtration is desired. Particles having a dimension larger
than the width of the fluid paths will be trapped or prevented from
passing through the filter while particles smaller than the width
of the fluid path will generally pass through. Some particle sizes
and/or types may not be harmful to the pump or spray assemblies
and, therefore, can be allowed to pass into the pump inlet.
[0005] Certain dishwashing appliances may be equipped with a fine
filter i.e., a filter for removing relatively small particles from
the wash or rinse fluids recirculated through the chamber of the
dishwashing appliance. Unfortunately, the fine filter is subject to
clogging during the cleaning process, which can substantially
reduce the flow of fluid provided to the pump and/or reduce the
amount of fluid that can be cleaned using the fine filter. It is
undesirable to manually remove and clean or replace the filter
during the cleaning process.
[0006] One approach to such problem is the use of a back flow of
water through the filter to remove the particles. However, all or
most of the resulting soiled water must then be drained out of the
appliance, thereby causing the appliance to consume more water
during the cleaning cycle. Another potential approach is the use of
a flow of water at an angle to the filter surface to dislodge
particles, but this approach also results in additional water
consumption.
[0007] Accordingly, a dishwasher appliance having a filtering
system that can clean particles clogging the filter would be
useful. Such a filtering system that can clean particles clogging a
filter that is used to remove fine particles from the wash and/or
rinse fluids would be particularly beneficial.
BRIEF DESCRIPTION OF THE INVENTION
[0008] The present invention provides a cleaner for a filter of a
dishwashing appliance. The filter cleaner rotates within the filter
and uses nozzles to remove particulates on the filter surface.
Energy from fluid flow caused by a pump is used to rotate the
filter cleaner. The particulates removed from the filter are pumped
away for disposal. Additional aspects and advantages of the
invention will be set forth in part in the following description,
or may be apparent from the description, or may be learned through
practice of the invention.
[0009] In one exemplary embodiment, the present invention provides
a dishwashing appliance that includes a wash chamber and a filter
for the receipt of fluid that has circulated through the wash
chamber. The filter has a chamber defined by a cylindrically-shaped
interior surface through which the fluid flows for filtering. A
filter cleaner is provided that includes a base defining a fluid
outlet for the flow of fluid from the chamber of the filter. A
bearing is supported upon the base. A rotatable body is positioned
within the chamber of the filter and is rotatably supported by the
bearing. The rotatable body defines an interior channel for fluid
flow that is in fluid communication with the fluid outlet of the
base. A pair of arcuate-shaped arms are positioned on opposing
sides of the rotatable body. Each arm has a nozzle positioned at a
distal end of the arm and adjacent to the interior surface of the
filter. The nozzle defines an inlet for the receipt of fluid and
particles from the interior surface of the filter. Each arm defines
a fluid pathway providing fluid communication between the inlet of
the nozzle and the interior channel of the rotatable body.
[0010] In another exemplary embodiment, the present invention
provides a dishwashing appliance having a wash chamber and a filter
for the receipt of fluid that has circulated through the wash
chamber. The filter has a chamber defined by a cylindrically-shaped
interior surface through which the fluid flows for filtering. A
filter cleaner is provided that has a base defining a fluid outlet
for the flow of fluid from the chamber of the filter. A bearing is
supported upon the base. A rotatable body is positioned within the
chamber of the filter and is rotatably supported by the bearing.
The rotatable body defines an interior channel for fluid flow that
is in fluid communication with the fluid outlet of the base. A
least one arm is positioned on the rotatable body. The arm has at
least one nozzle positioned along the arm and adjacent to the
interior surface of the filter, a bottom surface of the sump, or
both. The nozzle defines an inlet for the receipt of fluid and
particles from the interior surface of the filter. The at least one
arm defines a fluid pathway providing fluid communication between
the inlet of the nozzle and the interior channel of the rotatable
body.
[0011] These and other features, aspects, and advantages of the
present invention will become better understood with reference to
the following description and appended claims. The accompanying
drawings, which are incorporated in and constitute a part of this
specification, illustrate embodiments of the invention and,
together with the description, serve to explain the principles of
the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] A full and enabling disclosure of the present invention,
including the best mode thereof, directed to one of ordinary skill
in the art, is set forth in the specification, which makes
reference to the appended figures, in which:
[0013] FIG. 1 illustrates a front view of an exemplary embodiment
of a dishwashing appliance.
[0014] FIG. 2 provides a side, cross-sectional view of the
exemplary dishwashing appliance of FIG. 1.
[0015] FIG. 3 is a front view inside the wash chamber of the
exemplary dishwashing appliance of FIGS. 1 and 2. A grate or coarse
filter has been removed for purposes of additional clarity.
[0016] FIG. 4 is an exploded view of an exemplary filter assembly,
filter cleaner, and sump portion of a dishwashing appliance.
[0017] A cross-sectional view of an exemplary filter and filter
cleaner is provided in FIG. 5.
[0018] FIG. 6 is a perspective view of an exemplary embodiment of a
filter cleaner of the present invention.
[0019] FIGS. 7 and 8 are side, partial cross-sectional views of the
exemplary filter cleaner of FIG. 5.
[0020] FIG. 9 illustrates a perspective view of an exemplary
bearing as may be used with the present invention.
[0021] FIG. 10 is a top view of an exemplary filter cleaner and
filter--with a top portion of the filter removed for additional
clarity.
[0022] A cross-sectional view of an arm of an exemplary filter
cleaner is provided in FIG. 11.
[0023] FIG. 12 illustrates a cross-sectional view of another
exemplary embodiment of a filter and filter cleaner.
DETAILED DESCRIPTION OF THE INVENTION
[0024] Reference now will be made in detail to embodiments of the
invention, one or more examples of which are illustrated in the
drawings. Each example is provided by way of explanation of the
invention, not limitation of the invention. In fact, it will be
apparent to those skilled in the art that various modifications and
variations can be made in the present invention without departing
from the scope or spirit of the invention. For instance, features
illustrated or described as part of one embodiment can be used with
another embodiment to yield a still further embodiment. Thus, it is
intended that the present invention covers such modifications and
variations as come within the scope of the appended claims and
their equivalents.
[0025] As used herein, the term "article" may refer to, but need
not be limited to, dishes, pots, pans, silverware, and other
cooking utensils and items that can be cleaned in a dishwashing
appliance. The term "wash cycle" is intended to refer to one or
more periods of time during the cleaning process where a
dishwashing appliance operates while containing articles to be
washed and uses a detergent and water, preferably with agitation,
to e.g., remove soil particles including food and other undesirable
elements from the articles. The term "rinse cycle" is intended to
refer to one or more periods of time during the cleaning process in
which the dishwashing appliance operates to remove residual soil,
detergents, and other undesirable elements that were retained by
the articles after completion of the wash cycle. The term "drying
cycle" is intended to refer to one or more periods of time in which
the dishwashing appliance is operated to dry the articles by
removing fluids from the wash chamber. The term "fluid" refers to a
liquid used for washing and/or rinsing the articles and is
typically made up of water that may include additives such as e.g.,
detergent or other treatments. As used herein, "fluidly connected"
or "in fluid communication with" and the like means that fluid can
flow between the identified elements that may be directly connected
or may be connected through other components to allow fluid to flow
therethrough.
[0026] FIGS. 1 and 2 depict an exemplary domestic dishwasher 100
that may be configured in accordance with aspects of the present
disclosure. For the particular embodiment of FIGS. 1 and 2, the
dishwasher 100 includes a cabinet 102 having a tub 104 therein that
defines a wash chamber 106. The tub 104 includes a front opening
(not shown) and a door 120 hinged at its bottom 122 for movement
between a normally closed vertical position (shown in FIGS. 1 and
2), wherein the wash chamber 106 is sealed shut for washing
operations, and a horizontal open position for loading and
unloading of articles from the dishwasher. Latch 156 is used to
lock and unlock door 120 for access to wash chamber 106.
[0027] Upper and lower guide rails 124, 126 are mounted on tub side
walls 128 and accommodate roller-equipped rack assemblies 130 and
132. Each of the rack assemblies 130, 132 is fabricated into
lattice structures including a plurality of elongated members 134
(for clarity of illustration, not all elongated members making up
assemblies 130 and 132 are shown in FIG. 2). Each rack 130, 132 is
adapted for movement between an extended loading position (not
shown), in which the rack is substantially positioned outside the
wash chamber 106, and a retracted position (shown in FIGS. 1 and
2), in which the rack is located inside the wash chamber 106. This
rack movement is facilitated by rollers 135 and 139, for example,
mounted onto racks 130 and 132, respectively. A silverware basket
(not shown) may be removably attached to rack assembly 132 for
placement of silverware, utensils, and the like, that are otherwise
too small to be accommodated by the racks 130, 132.
[0028] The dishwasher 100 further includes a lower spray-arm
assembly 144 that is rotatably mounted within a lower region 146 of
the wash chamber 106 and above a tub sump portion 142 so as to
rotate in relatively close proximity to rack assembly 132. A
mid-level spray-arm assembly 148 is located in an upper region of
the wash chamber 106 and may be located in close proximity to upper
rack 130. Additionally, an upper spray assembly 150 may be located
above the upper rack 130.
[0029] The lower and mid-level spray-arm assemblies 144, 148 and
the upper spray assembly 150 are part of a fluid circulation
assembly 152 for circulating water and dishwasher fluid in the tub
104. The fluid circulation assembly 152 also includes a
recirculation pump 154 positioned in a machinery compartment 140
located below the tub sump portion 142 (i.e., bottom wall) of the
tub 104, as generally recognized in the art. Pump 154 receives
fluid from sump 142 to provide a flow to assembly 152 or optionally
a switching valve or diverter (not shown) may be used to select
flow. A heating element 170 can be used to provide heat during
e.g., a drying cycle.
[0030] Each spray-arm assembly 144, 148 includes an arrangement of
discharge ports or orifices for directing washing fluid received
from pump 154 onto dishes or other articles located in rack
assemblies 130 and 132. The arrangement of the discharge ports in
spray-arm assemblies 144, 148 provides a rotational force by virtue
of washing fluid flowing through the discharge ports. The resultant
rotation of the spray-arm assemblies 144, 148 and the operation of
spray assembly 150 using fluid from pump 154 provides coverage of
dishes and other dishwasher contents with a washing spray. Other
configurations of spray assemblies may be used as well.
[0031] The dishwasher 100 is further equipped with a controller 137
to regulate operation of the dishwasher 100. The controller may
include one or more memory devices and one or more microprocessors,
such as general or special purpose microprocessors operable to
execute programming instructions or micro-control code associated
with a cleaning cycle. The memory may represent random access
memory such as DRAM or read only memory such as ROM or FLASH. In
one embodiment, the processor executes programming instructions
stored in memory. The memory may be a separate component from the
processor or may be included onboard within the processor.
[0032] The controller 137 may be positioned in a variety of
locations throughout dishwasher 100. In the illustrated embodiment,
the controller 137 may be located within a control panel area 121
of door 120 as shown in FIGS. 1 and 2. In such an embodiment,
input/output ("I/O") signals may be routed between the control
system and various operational components of dishwasher 100 along
wiring harnesses that may be routed through the bottom 122 of door
120. Typically, the controller 137 includes a user interface
panel/controls 136 through which a user may select various
operational features and modes and monitor progress of the
dishwasher 100. In one embodiment, the user interface 136 may
represent a general purpose I/O ("GPIO") device or functional
block. In one embodiment, the user interface 136 may include input
components, such as one or more of a variety of electrical,
mechanical or electro-mechanical input devices including rotary
dials, push buttons, and touch pads. The user interface 136 may
include a display component, such as a digital or analog display
device designed to provide operational feedback to a user. The user
interface 136 may be in communication with the controller 137 via
one or more signal lines or shared communication busses.
[0033] It should be appreciated that the invention is not limited
to any particular style, model, or configuration of dishwasher. The
exemplary embodiment depicted in FIGS. 1 and 2 is for illustrative
purposes only. For example, different locations may be provided for
user interface 136, different configurations may be provided for
racks 130, 132, and other differences may be applied as well.
[0034] Referring now to FIGS. 2, 3, and 4, an exemplary filter
system 200 is located in sump portion 142 and provides filtered
fluid to pump inlet 162. Filter system 200 includes a filter or
filter cartridge 206 positioned in a cylindrically-shaped
receptacle 230 formed in sump portion 142. For this exemplary
embodiment, filter 206 is a fine filter that is removably received
in receptacle 230 through an opening 204 formed in sump portion
142. A handle 208 on filter top 288 allows a user to grasp filter
206 for removal. A drain pump 232 provides for removing waste water
from receptacle 230 for delivery to a drain 224. Sump portion 142
includes a recessed portion 226 over which a grate or coarse filter
210 is removably received.
[0035] Filtering system 200 removes soiled particles from the fluid
that is recirculated through the wash chamber 106 during operation
of dishwasher 100. After the fluid is filtered by passing through
filter 210 (e.g., a coarse filter--also referred as a first filter)
or filter cartridge 206 (e.g., a fine filter--also referred to as a
second filter), the filtered fluid is fed to the inlet 162 of pump
154 for return to the wash chamber 106 by way of fluid circulation
assembly 152. After being sprayed onto articles in the dishwashing
appliance using one or more of spray elements 144, 148, and 150,
the fluid eventually flows to sump portion 142 and is filtered
again.
[0036] More particularly, based on the shape of sump portion 142
(see FIG. 2), fluid flows down along vertical direction V to
filtering system 200. Referring now to FIGS. 4 and 5, openings 292
in the top 288 of filter 206 provide a fluid inlet to allow fluid
FF to flow into a chamber 220 defined by a cylindrically-shaped
interior surface 222 of filter 206. Fluid FF is fluid that flows
over the top of the coarse filter 210 without passing through its
openings 228 for coarse filtration. From internal chamber 220,
fluid FF can flow through one of the plurality of filter media 214,
216, or 218 (FIG. 4) forming cylindrically-shaped interior surface
222, whereby particulates P are removed from fluid FF.
[0037] After passing through the filter media, fluid FF combines
with fluid CF that has been filtered by coarse filter 210 by
passing through openings 228 therein. The combined flow of filtered
fluid F exits receptacle 230 to pump inlet 162 to be returned to
the wash chamber 106 by pump 154 for recirculation as previously
described. Accordingly, filtering system 200 acts to clean soil
particles from the fluid so as to e.g., protect pump 154 and/or the
spray assemblies from clogging as the fluid is recirculated during
the cleaning process of the dishwashing appliance 100 such as e.g.,
a wash or rinse cycle of appliance 100. The filtering system can
also assist in providing a fluid with less particles present during
the cleaning process.
[0038] As fluid passes through the media 214, 216, and 218 of
filter 206, particles P collect on the cylindrically-shaped
interior surface 222 of filter 206 and deleteriously affect the
filtration efficiency by blocking the filter media 214, 216, and
218. Drain pump 232 is in fluid communication with chamber 220 of
filter 206 and can be activated to move some of the particles P to
drain. However, without further action, some particles P will
remain lodged in the filter media on interior surface 222.
[0039] Accordingly, a filter cleaner 250 is provided to remove
particles P from interior surface 222. As shown in FIGS. 5, 6, 7,
and 8, filter cleaner 250 includes a base 252 defining a fluid
outlet 254 for the flow PF of particles and fluid from the chamber
220 of filter 206--i.e., fluid outlet 254 is in fluid communication
with chamber 220. A bearing 256 is supported on base 252 and can be
formed as a separate component therefrom for ease of assembly.
[0040] A rotatable body 258 is positioned on bearing 256 and is
located within chamber 220 of filter 206. Rotatable body 258 is
rotatably supported by bearing 256 and, more particularly, can
rotate (arrows R in FIG. 5) and/or pivot (arrows X in FIG. 8)
relative to bearing 256. Rotatable body 258 defines an interior
channel 260 for the flow PF of fluid containing particles from
interior surface 222 and/or chamber 220. Interior channel 260 is in
fluid communication with fluid outlet 254.
[0041] A pair of arcuate-shaped arms 262 are positioned on opposing
sides or in an opposing manner onto rotatable body 258. Each arm
262 has a nozzle 264 positioned at a distal end 294 that is
positioned away from rotatable body 258. Each nozzle 264 defines an
inlet 266 for the receipt of fluid containing particles P from
interior surface 222 and/or chamber 220 of filter 206. Each arm 262
defines a fluid pathway 268 (FIGS. 7 and 8) between inlet 266 and
the interior channel 260 of rotatable body 258, placing the two in
fluid communication with each other.
[0042] The activation of drain pump 232 causes a flow PF of fluid
containing particulates P to be drawn into inlets 266 of nozzles
264 substantially from interior surface 222 and some from chamber
220. The flow PF travels through each arm 262 and into rotatable
body 258. A sufficient level of flow PF (created by drain pump 232)
along with the arcuate shape of arms 262 causes rotatable body 258
and arms 262 to rotate in the direction of arrows R. Nozzles 264
are thereby caused to travel over the interior surface 222 of
filter 206 in a sweeping manner to suck or pull particulates P from
interior surface 222--thereby cleaning filter 206. Nozzles 264 each
extend longitudinally (direction L) along interior surface 222 of
filter 206. The flow PF travels through the fluid outlet 254 in
base 252 and through drain pump 232 for delivery to drain 224. For
example, controller 137 can activate pump 232 at appropriate times
during the cleaning process (e.g., at the end of a wash cycle) to
clean filter 206.
[0043] Rather than being pulled into nozzles 264, some particles P
may fall along the vertical direction V towards filter bottom 290
(FIG. 4) and base 252. To allow these particles to also be
evacuated from chamber 220, a recess 285 formed by interior wall
284 of base 252 and rotatable body 258 define a small gap 270
separating base 252 and rotatable body 258 near its bottom portion
276. Accordingly, some particles can pass through gap 270. Further,
because rotatable body 258 is pivotable relative to base 252 (FIG.
8), such movement can increase the size of gap 270 to a larger gap
272 to allow larger particles to pass.
[0044] As shown in FIGS. 7, 8, and 9, for this exemplary
embodiment, bearing 256 includes a bearing support 278 positioned
over the fluid outlet 254 of base 252. Bearing support 278 defines
one or more openings 282 for the passage of flow PF from channel
260 of rotatable body 258. A bearing shaft 280 extends
longitudinally (arrows L) along vertical direction V towards a seat
296 defined at a top portion 274 of rotatable body 258 within
channel 260. There, a distal end 281 of bearing shaft 280 (FIG. 9)
of bearing 256 is received into seat 296--while body 258 remains
rotatable and pivotable.
[0045] Referring now to FIGS. 5 and 10, the cylindrically-shaped
interior surface 222 of filter 206 defines an interior diameter ID.
For this exemplary embodiment, the overall width W, along the same
direction as interior diameter ID, of rotatable body 258 and
arcuate-shaped arms 262 is less than interior diameter ID so as to
define a small gap 298 between each nozzle 264 and interior surface
222, which allows rotation of arms 262 and body 258 even when a
build-up of particles P along interior surface 222 is present. In
one exemplary embodiment, gap 298 may be about 0.1 inches or less.
Other sizes for gap 298 may be used as well.
[0046] FIG. 11 provides a cross-sectional view of an arm 262. To
reduce drag on arms 262 during rotation, each arm 262 can be
provided with a cross-sectional shape conducive to the movement of
arm 262 through fluid in chamber 220. For the exemplary arm of FIG.
11, the cross-sectional shape along a plane that is perpendicular
to the flow of fluid PF is substantially tear-drop as shown. Other
shapes may be used as well. In addition, as previously stated, arm
262 defines a fluid pathway 268. To promote rotation of arms 262
and body 258, arm 262 tapers along a direction Z from the rotatable
body 258 towards nozzle 264.
[0047] Each fluid pathway 268 has a fluid inlet 300 and a fluid
outlet 302 defined by arm 262, as seen in FIGS. 10 and 11. To
promote the rotation of arms 262 and body 258 during operation of
drain pump 232, the relative angle .beta. of channel inlet 300 and
to channel outlet 302 can be manipulated. In one exemplary
embodiment, the relative angle .beta. is about 90 degrees. Other
angles may be used as well.
[0048] A variety of configurations and features can be used with
nozzles 264 to promote effective cleaning of filter 206. For
example, in the embodiments shown in FIGS. 5 and 12, the length of
nozzles 264 along vertical direction V is less than the height H of
the interior surface 222 along vertical direction V. In other
exemplary embodiments of the invention, the length of nozzles 264
can be increased so that nozzles 264 extend longitudinally over the
entire interior surface 222. Also, nozzles 264 are shown as
semi-cylinders. However, other shapes may be used.
[0049] In addition, nozzles 264 can be equipped with features for
scraping or wiping interior surface 222. In the exemplary
embodiment shown in FIG. 12, nozzles 264 include a wiping element
or brush 286 for cleaning surface 222. Other features may be used
as well.
[0050] The exemplary embodiment described above utilized cleaning
of a removable fine filter. Using the teachings disclosed herein,
one of skill in the art will understand that the present invention
may also be used with a fixed or non-removable filter as well.
Additionally, straight arms instead of arcuate arms may also be
used. In such case, the straight arms could be positioned e.g.,
onto the rotatable body at an angle to provide for rotation or
could otherwise be configured in a manner causing rotation. Also, a
single arm could also be used provided a counterweight is
positioned in an opposing manner on the rotatable body.
[0051] This written description uses examples to disclose the
invention, including the best mode, and also to enable any person
skilled in the art to practice the invention, including making and
using any devices or systems and performing any incorporated
methods. The patentable scope of the invention is defined by the
claims, and may include other examples that occur to those skilled
in the art. Such other examples are intended to be within the scope
of the claims if they include structural elements that do not
differ from the literal language of the claims or if they include
equivalent structural elements with insubstantial differences from
the literal language of the claims.
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