U.S. patent application number 10/809332 was filed with the patent office on 2005-09-29 for balancing fluid flow arrangement in an inner tub of a washing machine having an out-of-balance correction system.
Invention is credited to George, Paul E. II, Johnson, Troy A., Saunders, James H..
Application Number | 20050210929 10/809332 |
Document ID | / |
Family ID | 34988156 |
Filed Date | 2005-09-29 |
United States Patent
Application |
20050210929 |
Kind Code |
A1 |
George, Paul E. II ; et
al. |
September 29, 2005 |
Balancing fluid flow arrangement in an inner tub of a washing
machine having an out-of-balance correction system
Abstract
A washing machine is provided with an out-of-balance correction
system which can sense an out-of-balance condition of an inner tub
during a washing cycle. More specifically, the correction system
supplies an amount of balancing fluid to one or more receiving
pockets formed in the inner tub about front and rear injection
zones of the inner tub. Stationary injectors are provided to
selectively dispense the balancing fluid through molded passages
extending between an outer tub and the receiving pockets.
Inventors: |
George, Paul E. II; (Powell,
OH) ; Johnson, Troy A.; (Newton, IA) ;
Saunders, James H.; (Worthington, OH) |
Correspondence
Address: |
DIEDERIKS & WHITELAW, PLC
#301
12471 Dillingham Square
Woodbridge
VA
22192
US
|
Family ID: |
34988156 |
Appl. No.: |
10/809332 |
Filed: |
March 26, 2004 |
Current U.S.
Class: |
68/12.06 ;
68/12.02; 68/12.14; 68/12.19; 68/140; 68/23.1 |
Current CPC
Class: |
D06F 33/48 20200201;
D06F 37/225 20130101 |
Class at
Publication: |
068/012.06 ;
068/012.02; 068/012.14; 068/012.19; 068/023.1; 068/140 |
International
Class: |
D06F 037/20 |
Claims
I/we claim:
1. A washing machine comprising: a cabinet shell; an outer tub
fixedly mounted within the cabinet shell, said outer tub including
a rear portion and a main body portion; an inner tub rotatably
supported within the outer tub, said inner tub including a rear
portion defining a rear injection zone and a front portion defining
a front injection zone; a first plurality of balancing fluid
receiving pockets arranged about the rear injection zone; a second
plurality of balancing fluid receiving pockets arranged about the
front injection zone; a source of balancing fluid; and first and
second balancing fluid injectors fixed to the outer tub, said first
and second balancing fluid injectors being in fluid communication
with both the source of balancing fluid and the first and second
plurality of balancing fluid receiving pockets wherein, upon
detection of an out-of-balance condition of the inner tub during
operation of the washing machine, at least one of said first and
second balancing fluid injectors is operated to selectively deliver
an amount of balancing fluid to at least one of the first and
second pluralities of balancing fluid receiving pockets.
2. The washing machine according to claim 1, further comprising: a
shaft member projecting through a hub portion that projects from
the rear portion of the inner tub, said shaft member defining an
axis of rotation of the inner tub; and a plurality of raised wall
portions provided on the rear portion of the inner tub, said
plurality of raised wall portions extending from adjacent the shaft
member toward a peripheral edge of the inner tub, said plurality of
raised wall portions partially defining the first plurality of
balancing fluid receiving pockets.
3. The washing machine according to claim 2, wherein the axis of
rotation is substantially horizontal.
4. The washing machine according to claim 2, further comprising: a
return passage for transporting the balancing fluid from the first
and second plurality of balancing fluid receiving pockets toward
the source of balancing fluid, wherein a portion of said return
passage extends along the hub portion.
5. The washing machine according to claim 2, further comprising: a
cover plate including an inner surface having a plurality of raised
wall portions, a central opening receiving the shaft member, and an
inner contour, said cover plate being mated to the rear portion of
the inner tub.
6. The washing machine according to claim 5, further comprising: a
first plurality of raised baffles provided on the rear surface of
the inner tub, with at least one of the plurality of raised baffles
being positioned in each of the plurality of balancing fluid
receiving pockets; and a second plurality of raised baffles
provided on the inner surface of the cover plate and interposed
between the plurality of raised wall portions, said first and
second plurality of raised baffles being adapted to reduce sloshing
of balancing fluid in the balancing fluid receiving pockets when
the inner tub is rotated about the axis of rotation.
7. The washing machine according to claim 5, wherein the plurality
of raised wall portions provided on the rear portion of the inner
tub engage with the plurality of raised wall portions provided on
the inner surface of the cover plate to define the first plurality
of balancing fluid receiving pockets.
8. The washing machine according to claim 7, further comprising: a
diverter plate, positioned between the inner tub and the cover
plate, for directing the balancing fluid to the first and second
balancing fluid receiving pockets.
9. The washing machine according to claim 2, wherein the plurality
of raised wall portions partially define front plane channels for
directing the balancing fluid to the front injection zone.
10. The washing machine according to claim 9, further comprising: a
plurality of baffles arranged about an inner surface of the inner
tub, said baffles being adapted to agitate a load of laundry during
rotation of the inner tub; and wherein at least two of the
plurality of baffles include first and second passages for
directing the balancing fluid to the front injection zone.
11. The washing machine according to claim 10, wherein at least two
of the plurality of baffles are arranged directly opposite one
another.
12. The washing machine according to claim 10, wherein at least
three baffles are arranged in a symmetrical pattern about the inner
surface of the inner tub.
13. The washing machine according to claim 1, wherein the first
plurality of balancing fluid receiving pockets comprises eight
pockets arranged about the rear portion and the second plurality of
balancing fluid receiving pockets constitute four pockets provided
about the front portion.
14. The washing machine according to claim 13, wherein a balancing
fluid is supplied from injectors mounted remote from the inner tub,
said inner tub being adapted to rotate about an axis of rotation
within the outer tub.
15. The washing machine according to claim 14, wherein the
balancing fluid is supplied across an air gap separating the inner
and outer tubs.
16. An inner tub adapted to be rotatably supported within an outer
tub of a washing machine comprising: a rear portion defining a rear
injection zone; a front portion defining a front injection zone; a
first plurality of balancing fluid receiving pockets arranged about
the rear injection zone; a second plurality of balancing fluid
receiving pockets arranged about the front injection zone; and a
plurality of raised wall portions provided on the rear portion of
the inner tub, said plurality of raised wall portions partially
defining the first plurality of balancing fluid receiving
pockets.
17. The inner tub according to claim 16, further comprising: a
shaft member extending from a hub portion that projects from the
rear portion of the inner tub, said shaft member defining an axis
of rotation of the inner tub.
18. The inner tub according to claim 17, further comprising: a
return passage for transporting balancing fluid from the first and
second plurality of balancing fluid receiving pockets, wherein a
portion of said return passage extends along the hub portion.
19. The inner tub according to claim 16, further comprising: a
plurality of baffles arranged about an inner surface of the inner
tub, wherein at least two of the plurality of baffles include first
and second passages for directing balancing fluid to the front
injection zone.
20. The inner tub according to claim 19, wherein at least two of
the plurality of baffles are arranged directly opposite one
another.
21. The inner tub according to claim 16, wherein the first
plurality of balancing fluid receiving pockets comprises eight
pockets arranged about the rear portion and the second plurality of
balancing fluid receiving pockets constitute four pockets provided
about the front portion.
22. The inner tub according to claim 16, further comprising a cover
plate including an inner surface having a plurality of raised wall
portions, a central opening receiving shaft member, and an inner
contour, said cover plate being mated to the rear portion of the
inner tub.
23. The inner tub according to claim 22, further comprising: a
first plurality of raised baffles provided on the rear surface of
the inner tub, with at least one of the plurality of raised baffles
being positioned in each of the plurality of balancing fluid
receiving pockets; and a second plurality of raised baffles
provided on the inner surface of the cover plate and interposed
between the plurality of raised wall portions, said first and
second plurality of raised baffles being adapted to reduce sloshing
of balancing fluid in the balancing fluid receiving pockets when
the inner tub is rotated about the axis of rotation.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention pertains to the art of washing
machines and, more particularly, to a washing machine including an
inner tub having front and rear injection zones, each having a
respective plurality of balancing fluid receiving pockets for
receiving a balancing fluid for correcting an out-of-balance
correction condition.
[0003] 2. Discussion of the Prior Art
[0004] During operation of a washing machine, it is not uncommon
for an inner tub or spinner, which is rotatably mounted within the
washing machine, to become unbalanced due to a particular
distribution of a load of laundry. During the course of a typical
wash cycle, the inner tub is rotated at a relatively high or
extraction speed to extract water absorbed by the laundry. If the
laundry is unevenly distributed within the inner tub during the
extraction phase, an out-of-balance condition will develop. This
out-of-balance condition, when rotated at the extraction speed, can
cause excessive vibration.
[0005] Certainly, excessive vibration is detrimental to the
continued operation and reliability of the machine. Accordingly,
the prior art contains several examples of vibration or out-of
balance detection systems for sensing an actual or incipient
unbalance condition. In addition, it is known to correct the
out-of-balance condition without interrupting operation of the
washing machine even after exceeding a predetermined vibration
threshold. In general, prior art systems function to reduce the
rotational speed of the inner tub, provide a means of re-balancing
the inner tub or, less desirably, entirely shut down the machine
until a consumer corrects the problem by physically redistributing
the laundry within the machine.
[0006] Systems for re-balancing an out-of-balance washing machine
are well known in the prior art. Examples of such systems are
described in U.S. Pat. Nos. 3,983,035 and 4,991,247. In each of
these systems, the out-of-balance condition is corrected by
injecting a balancing fluid into a container located on an inner
peripheral portion of a rotating inner tub. Nozzles or other water
inlets are adapted to rotate with the inner tub and, upon receiving
a particular control signal, dispense a predetermined amount of
balancing fluid into the container(s) which eventually counteracts
the out-of-balance condition. The structure required to enable each
nozzle to rotate with the inner tub, maintain a fluid connection
between the nozzles and a central supply, and to provide a separate
supply to each container requires a complicated arrangement of
components which substantially increases the cost of the appliance.
In addition, it has been found that systems which do not include
containers for receiving the balancing fluid on both front and rear
portions of the rotating tub require a larger amount of balancing
fluid and, moreover, require a longer time period to facilitate
correction of the unbalanced condition which could expose the
appliance to unacceptable vibration levels.
[0007] In addition to the above, there exist a number of
complications associated with delivering the balancing fluid to the
containers. Specifically, complications exist with controlling the
amount of fluid introduced into the containers. When using a
pressurized system, precise control of the fluid is difficult to
achieve. Namely, when the fluid column is under pressure, it is
difficult to accurately control the amount of balancing fluid
introduced into the containers. A valve is cycled rapidly and
repeatedly to direct the balancing fluid into the rotating inner
tub. Rapid opening and closing of the valve must both initially
accelerate the balancing fluid and then subsequently stop the
forward motion of the fluid stream. When the fluid is under
pressure, i.e., when the fluid is brought up from a reservoir
located below the container, stopping the forward motion of the
fluid stream is often difficult. Once the valve is closed, the
fluid develops a tail that extends from the valve until the
cohesive bonds within the fluid stream break. This will result in
either too much fluid being dispensed into the container or,
alternatively, fluid being placed into the wrong container. In
either case, correcting the unbalanced state becomes a more
difficult and lengthy process.
[0008] While the above described systems for correcting an
out-of-balance condition in a washing machine are effective to a
degree, there still exists a need in the art for a system which
will more efficiently correct an unbalanced condition by using a
unpressurized fluid flow. Furthermore, there exists a need for an
improved unbalance correction system which is simple in
construction and operation, so as to be both reliable and cost
effective.
SUMMARY OF THE INVENTION
[0009] A washing machine constructed in accordance with the present
invention includes a cabinet shell, an outer tub, an inner tub and
a system for counteracting either an actual or incipient unbalance
condition in a reliable, accurate and cost effective manner. More
specifically, the present invention is directed to the inner tub
including a plurality of balancing fluid receiving pockets. In
accordance with the invention, the inner tub preferably includes
front and rear injection zones which include the plurality of
balancing fluid receiving pockets.
[0010] The washing machine further incorporates first and second
injectors fixedly mounted at a rear portion of the outer tub that
are adapted to selectively dispense the balancing fluid into the
front and rear injection zones. Preferably, the first injector is
provided to dispense the balancing fluid into the plurality of
pockets arranged about the rear portion of the inner tub, and the
second injector is provided to dispense the balancing fluid into
the plurality of pockets arranged about the front portion of the
inner tub.
[0011] In a preferred form of the invention, a plurality of raised
wall portions partially define the plurality of balancing fluid
receiving pockets arranged about the rear portion of the inner tub.
Additionally, the plurality of raised wall portions partially
define passages for transporting the balancing fluid to the front
injection zone. More specifically, baffles carried by an inner
portion of the inner tub interconnect the passages provided on the
rear surface with the plurality of balancing fluid pockets arranged
about the front injection zone. In the most preferred form, a cover
plate, having a plurality of raised wall portions that correspond
to the raised wall portions provided on the inner tub, is mated to
the rear portion of the inner tub to define the rear injection
zone.
[0012] The inner tub also includes a plurality of return passages
adapted to conduct the balancing fluid from the front and rear
injection zones back toward a balancing fluid reservoir. More
specifically, the return passages lead the balancing fluid, under
force of gravity, along a central hub portion of the inner tub. The
balancing fluid travels down the central hub portion for ultimate
delivery back to the reservoir of the washing machine.
[0013] Based on the above, it should be readily apparent that the
invention provides for a relatively simple, inexpensive unbalance
correction system which is able to remedy an out-of-balance
condition sensed by an unbalanced detection assembly. In any event,
additional objects, features and advantages of the invention will
become more readily apparent from the following detailed
description of a preferred embodiment of the invention, when taken
in conjunction with the drawings wherein like reference numerals
refer to corresponding parts in the several views.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a plan view of a laundry appliance incorporating
an on-axis injection system constructed in accordance with the
present invention;
[0015] FIG. 2 is an exploded view of an outer tub portion of the
laundry appliance of FIG. 1, showing a balancing fluid and delivery
system for the on-axis injection system of the present
invention;
[0016] FIG. 3 is an exploded view of an inner tub assembly
depicting rear injection plane fluid receiving pockets for the
on-axis injection system of the present invention;
[0017] FIG. 4 is a perspective view of a back plate of the inner
tub assembly of FIG. 3 constructed in accordance with a preferred
embodiment of the present invention;
[0018] FIG. 5 is a perspective view of the inner tub of FIG. 3
depicting front injection plane fluid receiving pockets arranged in
accordance with a preferred embodiment of the present
invention;
[0019] FIG. 6 is a partial cross-sectional view of the on-axis
injection system, showing a balancing fluid injector valve and
injector nozzle assembly arranged in accordance with the present
invention;
[0020] FIG. 7 is an exploded view of the balancing fluid injector
valve of FIG. 6;
[0021] FIG. 8 is a perspective view of an outlet portion of the
balancing fluid injector valve of FIG. 7;
[0022] FIG. 9 is a another perspective view of the outlet portion
of the balancing fluid injector valve;
[0023] FIG. 10 is a perspective view of a solenoid valve coil of
the balancing fluid injector valve of FIG. 7, showing a plunger
receiving base and associated pole piece;
[0024] FIG. 11 is a perspective view of the nozzle assembly
incorporated in the on-axis injection system of FIG. 6; and
[0025] FIG. 12 is a partially exploded, detail view of a hub
portion of the outer tub, showing a preferred mounting arrangement
of the nozzle assembly of FIG. 10.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0026] With initial reference to FIG. 1, a laundry appliance
constructed in accordance with the present invention is generally
indicated at 2. As shown, laundry appliance 2 constitutes a
horizontal axis machine including an outer cabinet shell 4 having
an associated door 6 which can be selectively opened to expose a
washing basket 8. In the embodiment shown, washing basket 8, also
referred to as an inner tub or spinner, is mounted within an outer
tub 9 (FIG. 2) in cabinet shell 4 for rotation about an axis which
is angled slightly downward toward a rear portion of cabinet shell
4. For the sake of completeness, inner tub 8 is shown to include a
plurality of holes 10, as well as various generally triangular
shaped and radially inwardly projecting fins or blades 12 which are
fixedly secured to an internal peripheral portion of inner tub 8.
In a manner known in the art, inner tub 8 is adapted to rotate
during both wash and rinse cycles, such that articles of clothing
placed therein actually tumble through either a water/detergent
solution or rinse water supplied within inner tub 8. Water for the
selected operation is actually contained within outer tub 9 in a
manner known in the art. For the sake of completeness, laundry
appliance 2 is also shown to include an upper cover 14 for
providing access to an area for adding detergent, bleach, softener
and the like.
[0027] In accordance with one embodiment of the present invention,
laundry appliance 2 is shown to include a control panel 16 arranged
on an upper rear portion of cabinet shell 4. In the embodiment
depicted, control panel 16 includes a plurality of cycle setting
buttons 20-22, a start/stop button 23 and a rotary control knob 24.
Buttons 20-22 and control knob 24 are utilized to establish a
desired washing operation for laundry appliance 2. Since the
general setting and operating of laundry appliance 2 is known in
the art and does not form part of the present invention, these
features will not be discussed here in detail. However, in general,
buttons 20-22 are used to manually set desired operational
parameters, including a desired fill level based on load size, wash
and rinse temperatures, along with the type of washing operation,
such as gentle, normal or the like cycles, typically based on the
particular fabrics being washed. On the other hand, control knob 24
is used to set the type and duration of the washing operation.
Although control panel 16 is shown to include buttons 20-22, start
button 23 and control knob 24, it should be understood that these
particular types of control elements are merely intended to be
exemplary and that other types of control elements, including
electronic control elements, soft touch buttons, a touch screen LED
panel and the like could be readily utilized.
[0028] Arranged within control panel 16 is a control unit or CPU
39. Control unit 39 includes unbalance detection circuit 41 for
detecting actual or incipient unbalanced load conditions occurring
within inner tub 8. Typically, during a spin cycle, a particular
distribution of laundry within inner tub 8 may lead to an
out-of-balance condition when inner tub 8 is rotated at high speed
which can generate excessive vibrations of laundry appliance 2. It
should be understood that, at this point the details of unbalance
detection circuit 41 are not part of the present invention and can
actually take various forms, such as that disclosed in commonly
assigned U.S. Pat. No. 6,422,047 which is hereby incorporated by
reference. In any case, unbalance detection circuit 41 receives
signals from an unbalance detecting unit (not shown) and, depending
on these signals, provides inputs to tub drive control 44, cycle
control 46 and unbalance correction controls 47 which, in turn,
provides the control to the on-axis injection system of the present
invention as described more fully below.
[0029] Referring to FIG. 2, laundry appliance 2 preferably includes
an on-axis injection system including a balancing fluid storage
reservoir 53 having a plurality of side portions 56-59. More
specifically, reservoir 53 is integrally molded to an upper region
of outer tub 9. Furthermore, a top portion or cover (not shown)
extends over side portions 56-59 enclosing reservoir 53 to prevent
foreign objects from entering and contaminating the balancing
fluid, as well as to prevent fluid loss. With this arrangement, an
amount of balancing fluid, preferably in the range of 1-2 gallons,
is stored within reservoir 53, with a portion of the balancing
fluid being selectively delivered to inner tub 8 upon the detection
of an out of balance condition. That is, reservoir 53, inner tub 8
in addition to feed and return conduits (not shown) form at least a
portion of a closed balancing fluid containment system so that once
filled, additional balancing fluid need never be added to the
system. Preferably, the balancing fluid is a mixture of water and a
propylene or ethylene glycol solution. More preferably, the
balancing fluid is a mixture of water and a salt or calcium
chloride solution, or other substances having similar
qualities.
[0030] In accordance with a preferred embodiment of the present
invention, the balancing fluid is delivered to inner tub 8 through
a plurality of fluid delivery or receiving channels which are, at
least partially, molded onto a rear portion 60 of outer tub 9. More
specifically, as will be detailed more fully hereafter, first and
second fluid delivery channels 70 and 71 carry the balancing fluid
from reservoir 53 to particular pockets carried by inner tub 8. A
third, drain or return channel 73 is further provided on rear
portion 60 of outer tub 9 to collect expended balancing fluid from
inner tub 8 and ultimately carry the fluid back to reservoir 53
through a hub portion 76. As shown, a plurality of raised wall
portions 77-81 extend from hub portion 76 and thereafter separate
and define each of the first, second and third channels 70, 71 and
73. Furthermore, in order to reduce the possibility of fluid
leaking between first and second delivery channels 70 and 71, a
segment of wall portion 81 includes a double wall segment 83.
Finally, in addition to partitioning the fluid channels 70, 71 and
73, raised wall portions 77-81 and 83 increase the stiffness and
thus the structural integrity of outer tub 9.
[0031] In accordance with a preferred arrangement, first and second
fluid delivery channels 70 and 71 open to reservoir 53 at
respective upper portions 90 and 91. From upper portions 90 and 91,
balancing fluid delivery channels 70 and 71 extend along rear
portions 94 and 95 of outer tub 9 before opening to delivery
channels 99 and 100 at hub portion 76. Preferably, rear portions 94
and 95 are formed with a minimal number of undulations or the like
which could lead to inconsistency in balancing fluid delivery.
Similarly, a drain opening 105 leads from hub portion 76 to an
upper or inner radial portion of drain channel 73. As will be
detailed more fully below, as the balancing fluid returns from
inner tub 8, it passes along hub portion 76 to drain opening 105
traveling along a rear portion 106 prior to being returned to
reservoir 53 as will be discussed more fully below.
[0032] In order to ensure the existence of a proper pressure head,
as well as to fully close off the delivery system, a cover plate
120 is secured to raised wall portions 77-81 and 83 on outer tub 9.
As shown, cover plate 120 is defined by an outer contour 121
corresponding to raised wall portions 77-81 and includes a notched
portion 123 adapted to partially extend about hub portion 76. As
further shown in FIG. 2, arranged on cover plate 120 are first and
second cylindrical receivers 130 and 131. More specifically,
cylindrical receivers 130 and 131 are positioned at delivery
channels 70 and 71 in order to position one of a pair of balancing
fluid injector valves, which are indicated at 135 and 135', within
delivery channels 99 and 100 respectively.
[0033] Although further details of injector valve assemblies 135
and 135' will be provided hereafter, in general, each of injector
valve assemblies 135 and 135' includes at least an outlet or base
portion 145 having a curvilinearly tapered end portion 146 adapted
to matingly seat in a respective outlet delivery channel 99 and
100, an intermediate portion 147 and a valve coil 148. Most
preferably end portion 146 evinces a generally spherical profile
that has been truncated. In a preferred form of the invention,
injector valve assemblies 135 and 135' are secured within
respective cylindrical receivers 130 and 131 through a plurality of
raised mounting lugs 155-158 arranged adjacent to each cylindrical
receiver 130, 131. More specifically, injector valve assemblies 135
and 135' are secured to mounting lugs 155-158 through respective
bracket members 165 by a plurality of mechanical fasteners 170-173.
In a more preferred form, a resilient ring 175 is positioned
between valve coil 148 and mounting bracket member 165 to account
for any excessive vibrations or misalignment problems with respect
to injector assemblies 135 and 135' within outlet delivery channels
99 and 100.
[0034] Opening from a lower portion of cover plate 120 is a drain
conduit 180 which directs returning balancing fluid from drain
channel 73 to reservoir 53. In accordance with a preferred
embodiment of the present invention, drain conduit 180
interconnects to reservoir 53 through a pump (not shown) which
functions to return the balancing fluid from drain channel 73 to
reservoir 53. In accordance with another embodiment of the present
invention, drain conduit 180 interconnects with an intermediate
sump and pump (not shown) adapted to store the used balancing fluid
until demanded through correction controls 47. In any event, it is
only important to note that the balancing fluid is preferably
returned to reservoir 53 in a manner so as to define a closed
system. In this way, there is no further need to add balancing
fluid once laundry appliance 2 leaves the factory.
[0035] Referring to FIG. 3, the on-axis injection system is
primarily carried by inner tub 8. In the embodiment shown, inner
tub 8 includes a cylindrical spinner body member 190, a back or
cover plate 195 and a diverter plate 197 sandwiched therebetween.
Spinner body member 190 is preferably formed with a first end
defining a rear injection zone 200 and a second end or front
injection zone 203. As will be discussed more fully below, a shaft
member 204 rotatably supports inner tub 8 within sealed bearings
205-206 (FIG. 6). A first plurality of balancing fluid receiving
receptacles or rear injection plane pockets 210-217 are arranged
about rear injection zone 200. Each of the plurality of rear
injection plane pockets 210-217 is partially defined by a first
plurality of raised wall portions, one of which is indicated at
215. In a similar manner, a plurality of front plane diverter
channels indicated at 220-223 are partially defined by a second
plurality of raised wall portions, one of which is shown at 225.
More specifically, front plane diverter channels 220-223
respectively lead to front plane passages 227-230 which, in turn,
fluidly interconnect front plane diverter channels 220-223 with a
plurality of front plane injection pockets 232-235 (FIG. 5) through
respective ones of blades 12.
[0036] Rear portion 200 of spinner body member 190 is closed off by
cover plate 195. As best seen in FIG. 4, cover plate 195 includes
an inner surface 237 having a plurality of first and second raised
wall portions, such as those generally indicated at 239 and 241. In
this manner, each of the plurality of rear plane pockets 210-217
and front plane channels 220-223 are isolated one from the other.
Additionally, cover plate 195 includes a central opening 250 having
a raised rim 253 located on an outer surface 255 (FIG. 3) and an
inner contour 260 arranged adjacent to central opening 250 on inner
surface 237 (FIG. 4). Inner contour 260 is formed so as to receive
diverter plate 197. Referring to FIG. 3, diverter plate 197
includes a plurality of raised portions (not separately labeled)
which define a plurality of front panel pathways 265-268 that
communicate with channels 220-223.
[0037] Referring to FIGS. 3 and 4, rear portion 200 of spinner body
member 190 and inner surface 237 of cover plate 195 include a
plurality of raised, baffle portions indicated generally at 270 and
271. As shown, raised portions 270 and 271 are provided within rear
plane pockets 210-217 as well as front plane channels 220-223, and
are spaced from both central opening 250 and a central recess 275
of spinner body member 190. Raised portions 270 and 271 form
baffles that discourage the sloshing of fluid within rear plane
pockets 210-217 and front plane channels 220-223 when spinner body
member 190 is revolving at a low rpm. Raised portions 270 and 271
include passages and/or holes (not separately labeled) at the
periphery of spinner body member 190 that allow water to flow
slowly between volumes formed by raised portions 270 and 271 when
cover plate 195 is attached to spinner body member 190. It is
desirable to have between 1 and 5 raised portions 270, 271 in each
rear plane pocket 210-217 and front plane channel 220-223. The
passages through each raised portion 270, 271 should have an area
equivalent to round holes of between {fraction (1/8)} inch and 2
inches in diameter to provide adequate water flow between each rear
plane pocket 210-217 and front plane channel 220-223. The most
preferred number of baffles is three and the most preferred area is
about {fraction (1/4)}" equivalent diameter. Similar baffles (not
shown) are incorporated into the front plane injection pockets
232-235.
[0038] With this arrangement, balancing fluid can be dispensed into
any combination of rear and front plane pockets 210-217, 232-235 to
compensate for an out-of-balance condition of rotating inner tub
assembly 8. With specific reference to FIGS. 2, 3, 5 and 6,
dispensing a dollop of balancing fluid between diverter plate 197
and cover plate 195 near shaft member 204 forces the balancing
fluid into one of the plurality of front plane channels 220-223
which lead to passages 227-230 and ultimately to front injection
zone 203. Conversely, dispensing a dollop of balancing fluid
between diverter plate 197 and rear zone 200 near shaft member 204
forces the balancing fluid into one of the plurality of rear plane
pockets 210-217. The particular pocket 210-217, 232-235 into which
the dollop will fall is based on both the sensed need for
correction, the injector 135, 135' activated, and the timing of the
injection. At this point it should be realized that the actual
number of front or rear pockets employed could be varied in
accordance with the invention, with the preferred range being
between 3 and 12. In any case, by dispensing the dollop of
balancing fluid near shaft member 204, the dollop will contact
inner tub 8 at a point of low velocity to minimize splash in order
to increase the accuracy of the injection.
[0039] As will be detailed more fully below, once inner tub
assembly 8 ceases to spin, the need for balancing fluid in either
rear injection zone 200 or front injection zone 203 is eliminated.
Accordingly, as the radial velocity of inner tub 8 decreases, so
does the centrifugal force holding the balancing fluid within a
particular pocket 210-217 and 232-235. As the force continues to
decrease, the balancing fluid begins to migrate to shaft member 204
and collect in recess 275 (FIGS. 3 and 6) as each respective pocket
210-217 and 232-235 passes a top point of rotation. Once tub
assembly slows sufficiently, the balancing fluid travels along
shaft member 204 to drain channel 73 and ultimately returns to
reservoir 53.
[0040] Upon sensing an actual or incipient out-of-balance
condition, correction controls 47 signals the on-axis injection
system to dispense an out-of-balance correcting balancing fluid
into particular portions of inner tub assembly 8. In order to
offset the out-of-balance condition, correction control 47
determines into which plane and into which pocket in that plane an
injection of balancing fluid is required. At this point, a timing
mechanism (not shown) timely activates one of the pair of injectors
135 and 135' corresponding to the particular injection zone 200 and
203 into which an injection of fluid is necessary. Reference will
now be made to FIGS. 6-9 in describing the preferred construction
of injectors 135 and 135'. Since the structure of each injector
135, 135' is identical, a description of injector 135 will be made
and it is to be understood that injector 135' has commensurate
structure.
[0041] In accordance with a preferred embodiment as discussed
above, injector 135 takes the form of a solenoid type valve and
includes base portion 145 having/curved or tapered end portion 146,
an intermediate portion 147 and valve coil 148. More specifically,
end portion 146 includes a first end defining an outlet opening 283
and a second end having an inner surface portion 286 defining a
central recess 288. Extending between outlet opening 283 and an
inlet opening 290 is a delivery conduit 292 having a central
passage 293. Preferably, delivery conduit 292 is integrally molded
to base portion 145 and includes a plurality of tapering rib
elements 297-299. More specifically, rib elements 297-299 support
delivery conduit 292 and define a balancing fluid inlet or supply
opening 305 (FIG. 8). Finally, as will be detailed more fully
below, a plurality of locating holes, one of which is indicated at
309, are arranged about inner surface portion 286.
[0042] In accordance with the preferred embodiment shown, inlet
opening 290 is adapted to be selectively sealed through application
of a diaphragm 319 positioned along inner surface portion 286. More
specifically, diaphragm 319 includes surface 323 which extends into
and seals about central recess 288. As best seen in FIG. 8, a
sealing member 327 is centrally arranged on surface 323 and
positioned to selectively close off inlet opening 290 through axial
movement of a plunger 335 which is fixed to diaphragm 319.
[0043] More specifically, as best shown in FIG. 7, plunger 335
includes a first end portion 336 interconnected to diaphragm 319,
and a second end portion 337. As best seen in FIG. 9, second end
portion 337 includes an annular notch or groove 339 within which is
arranged a cushioning ring 340. Cushioning ring 340 is provided to
reduce the effects on valve assembly 135 from the repeated cycling
of plunger 335. In a typical solenoid valve operation, plunger 335
is drawn into a cylindrical bore 343 that extends within valve coil
148 (FIG. 10). Each time plunger 335 enters bore 343, second end
337 of plunger 335 is forced against a pole piece or end stop
344.
[0044] Experience has shown that repeated operation of the valve
results in wear to both second end 337 and pole piece 344 causing
the calibration of valve assembly 135 to exceed manufacturer
specifications. However, by incorporating cushioning ring 340 into
second end portion 337, the life of valve assembly 135 can be
extended such that prolonged operation is possible. In addition,
cushioning ring 340 helps control the physical profile of the
balancing fluid dollop as it passes from outlet 283. Because of the
critical role that cushioning ring 340 plays in the performance of
valve assembly 135, it would generally be considered desirable to
have pole piece 344 as smooth as possible to minimize wear on
cushioning ring 340. However, each time cushioning ring 340
contacts pole piece 344, an amount of air is trapped within a
center portion 345 of cushioning ring 340. Because the force
between pole piece 344 and plunger 335 becomes large as plunger 335
approaches pole piece 344, the pressure of the trapped air can
become high and air may leak from the center of cushioning ring 340
in an uncontrolled manner.
[0045] When the electrical power to valve coil 148 is removed,
plunger 335 moves away from pole piece 344. If air has leaked from
the center of cushioning ring 340, then a vacuum may be drawn
within cushioning ring 340 to retard or prevent the movement of
plunger 335, which undesirably changes the amount and location of
the injected fluid. In order to alleviate the problem of trapped
air, pole piece 344 is subject to a texturing process wherein the
surface of pole piece 344 is formed with channels, notches,
grooves, or the like. With this arrangement, trapped air can escape
from center portion 345, thereby enabling plunger 335 to fully
retract into bore 343 without excessive pressure build-up. Further,
the texturing provides a path for air to reenter center portion 345
as plunger 335 is released so that vacuum does not retard plunger
motion. It should be understood that a polished pole piece may work
satisfactorily for some applications, but where cycle-to-cycle
consistency is desired, a roughened or textured pole piece 344
offers more consistent performance. Finally, a coil spring 348 is
arranged about plunger 335 to bias diaphragm 319 against inlet
opening 290 during periods of inactivity.
[0046] With further reference to FIGS. 7-9, intermediate portion
147 of valve assembly 135 has a first side surface 355 and a second
side surface 356 between which extends a central opening 358. More
specifically, first and second side surfaces 355 and 356 are
surrounded by a cylindrical side wall portion 360. Intermediate
portion 147 is fitted to base portion 145 with an annular notch or
groove 362, which is adapted to receive a sealing ring 364, being
defined between base portion 145 and cylindrical side wall portion
360. Actually, sealing ring 364 projects radially outwardly of
cylindrical side wall portion 360. With this arrangement, sealing
ring 364 maintains a fluid tight seal about injector 135 within
cylindrical receiver 130 (FIG. 6). Therefore, valve assembly 135
will seat within receiver 130 despite differences resulting from
manufacturing tolerances. In the embodiment shown, sealing ring 364
constitutes a resilient O-ring, however, it should be understood
that various ring profiles can be used to obtain the same result.
In addition, arranged on first side surface 355 are a first
plurality of locating pins, one of which is indicated at 366. Each
locating pin 366 is adapted to extend into a respective locating
hole 309 of base portion 145 for positioning intermediate portion
147 in a particular alignment with base portion 145. Similarly, a
second plurality of locating pins 368 project from second side
surface 356. The second plurality of locating pins 368 are adapted
to engage into a respective notch portion 375 (FIG. 10) on valve
coil 148 to maintain a particular alignment between intermediate
portion 147 and valve coil 148.
[0047] Valve assemblies 135 and 135' are selectively activated
though application of voltage to electrical terminals 380 and 381
(FIG. 7) of valve coil 148. Referring to FIGS. 3 and 6, upon
determining into which injection zone 200 or 203 and, more
importantly, into which pocket(s) 210-217, 232-235 in that zone the
balancing fluid is to be injected, control 47 times the activation
of a particular injector 135, 135' to deliver the balancing fluid
necessary to offset the out-of-balance condition. Upon activation,
plunger 335 is drawn into valve coil 148 exposing inlet opening 290
to a flow of balancing fluid from supply opening 305. In a
preferred form of the invention, the voltage applied to activate
valve coil 148 is ramped, which enables greater control over the
movement of plunger 335 and, by extension, the amount of fluid
dispensed. In any event, the balancing fluid travels through
central passage 293, passes from outlet opening 283 and flows
through a respective gap or passage, one of which is indicted at
396, into a nozzle assembly 400 which dispenses the balancing fluid
into the desired pocket 210-217 or 232-235. Preferably passage 396
is in the range of 1/4"-1" and, more preferably, from {fraction
(3/8)}"-1/2".
[0048] As best seen in FIG. 11, nozzle assembly 400 is defined by
an arcuate main body portion 403 having a first surface 405, an
opposing second surface 406 and surrounding side surface portions
408-411. In accordance with a preferred form of the present
invention, first and second fluid inlet ports 420 and 421, each
having a respective raised side portion 422 and 423, are arranged
on first surface 405. More specifically, raised side portions 422
and 423 provide a flange which help locate nozzle assembly 400 on
hub 76 and further assist in sealing nozzle assembly 400 to passage
396. Inlet ports 420 and 421 open to respective nozzle elements 430
and 431, each having an outlet 433, 434 which extends from second
surface 406 into a respective front or rear injection zone 203 or
200 respectively. Each outlet 433, 434 opens substantially
perpendicular to a respective passage 396 and defines a sharp
internal edge orifice (not separately labeled) which enables the
low pressure system to cause a particular dollop of balancing fluid
to remain cohesive when being dispensed. In addition, this
arrangement also causes each dollop to have a clean break on the
back portion thereof and minimizes follow-on droplets which could
reduce the accuracy of the injection and may result in water
placement outside a desired pocket 210-217, 232-235. The internal
edges of passages 423 and 434 are considered sharp when their
length perpendicular to passage 396 is less than 1/8", preferably
less then {fraction (1/16)}" and, most preferably, less than
0.030". The sharp internal edge of passages 423 and 434 preferably
have a radius of up to 0.010". Finally, as will be detailed more
fully below, nozzle assembly 400 includes a pair of locating pins
440 and 441, as well as a plurality of mounting apertures 450-452
arranged along first surface 405.
[0049] Referring to FIG. 12 which depicts a preferred mounting
arrangement of the present invention, nozzle assembly 400 is
secured to an inner surface 469 of hub portion 76 through a
plurality of mechanical fasteners 476-478. As shown, a
corresponding pair of locating holes 480 and 481 are arranged along
a portion of inner surface 469 to receive a respective locating pin
440, 441 which position and align nozzle inlets 420 and 421 with
respective outlets 484 and 485. Fasteners 476-478 are actually
received in a plurality of threaded bores 490-492 provided on inner
surface 469.
[0050] Upon sensing an unbalanced condition of inner tub 8,
unbalance detection circuit 41 in CPU 39 determines the magnitude
and location of the unbalanced condition. At this point, correction
control 47 calculates the amount of balancing fluid, and into which
one of the plurality of pockets 210-217 and 232-235 to inject the
balancing fluid to offset the unbalanced condition. More
specifically, a timing mechanism (not shown) monitors the position
of the inner tub 8 relative to injectors 135 and 135'. Through use
of the timing mechanism, unbalance correction control 47 operates
the appropriate one of injectors 135 and 135', at a proper time and
for a desired duration, to dispense the calculated amount to fluid
into the requisite pocket 210-217, 232-235. Centrifugal force,
generated by rotating inner tub 8, forces the balancing fluid into
the appropriate one of the plurality of pockets 210-217, 232-235.
This process repeats itself until the unbalance condition is
corrected as sensed by unbalance detection circuit 41. As indicated
above, once the centrifugal force keeping the balancing fluid
within the particular pocket 210-217, 232-235 diminishes
sufficiently, the balancing fluid, under force of gravity, returns
to drain channel 73. As shown in FIG. 12, this return flow is
accomplished with an inner surface 469 of hub portion 76 being
provided with at least one return port indicated at 500. In this
manner, the balancing fluid is ultimately returned to reservoir 53
for continued use as required by unbalance control 47.
[0051] As shown in FIG. 12, injectors 135 and 135' are located on
one side of hub portion 76. Although the precise location of
injectors 135 and 135' is not critical, it is important that they
be placed on the side of machine 2 where the spinner rotation
produces a downward motion. In this way, the balancing fluid is
injected at a location where the maximum time is available for the
fluid flow to the periphery of spinner 8 before the appropriate
pocket 210-217, 232-235 passes over the top of machine 2. If
nozzles 135 and 135' are not placed on the downward moving side,
some fluid may not traverse to the outside of spinner 8 where
centrifugal force is maximum and may fall back out of a respective
pocket 210-217, 232-235 when spinner 8 is moving more slowly, such
as during an initial balance process.
[0052] 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, the particular
shape of the balancing fluid receiving pockets can be varied
without departing from the scope of the present invention.
Furthermore, while water is the preferred balancing fluid, a
variety of other viscous solutions are adaptable for use in the
above disclosed system. In general, the invention is only intended
to be limited by the scope of the following claims.
* * * * *