U.S. patent application number 09/899475 was filed with the patent office on 2001-12-20 for control for and automatic washer with spray pretreatment.
Invention is credited to Aldrin, John Carl, Euler, John W., Pinkowski, Robert J., Whah, Kenneth N..
Application Number | 20010052249 09/899475 |
Document ID | / |
Family ID | 23323893 |
Filed Date | 2001-12-20 |
United States Patent
Application |
20010052249 |
Kind Code |
A1 |
Whah, Kenneth N. ; et
al. |
December 20, 2001 |
Control for and automatic washer with spray pretreatment
Abstract
This invention relates a control for an automatic washer
incorporating a spray pretreatment or stain care cycle. In order to
manage the occurrence of the condition of suds lock, the state of
the washing machine related to the suds lock condition during spray
pretreatment is determined by one or more of a number of methods.
With this information concerning the state of the spray
pretreatment process, the occurrence of suds lock can be
ascertained and the cycle can be controlled accordingly to minimize
negative effects resulting from a prolonged suds lock condition.
Additionally, with certain information related to the occurrence of
suds lock, steps can be taken during the spray pretreatment portion
of the cycle to avoid the condition of suds lock altogether. Using
the same primary process for measuring suds lock, load size can
also be ascertained. Information about load size can be used to
control the wash cycle.
Inventors: |
Whah, Kenneth N.; (Porter,
IN) ; Euler, John W.; (St. Joseph, MI) ;
Pinkowski, Robert J.; (Baroda, MI) ; Aldrin, John
Carl; (Lake Bluff, IL) |
Correspondence
Address: |
WHIRLPOOL PATENTS COMPANY - MD 0750
500 RENAISSANCE DRIVE - SUITE 102
ST. JOSEPH
MI
49085
US
|
Family ID: |
23323893 |
Appl. No.: |
09/899475 |
Filed: |
July 5, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09899475 |
Jul 5, 2001 |
|
|
|
09338213 |
Jun 22, 1999 |
|
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Current U.S.
Class: |
68/12.04 ;
68/12.02; 68/12.05; 68/12.12; 68/12.21; 68/12.27; 68/23.5 |
Current CPC
Class: |
D06F 39/06 20130101 |
Class at
Publication: |
68/12.04 ;
68/12.02; 68/12.05; 68/12.27; 68/12.12; 68/23.5; 68/12.21 |
International
Class: |
D06F 033/02 |
Claims
The embodiments of the invention in which an exclusive property or
privilege is claimed are defined as follows:
1. A washing machine apparatus for washing a textile wash load
having a wash tub for receiving a wash liquid within which there is
a rotatable wash zone including a peripheral wall, a motor for
rotating said peripheral wall and said wash load in said wash zone
about a predetermined axis and a recirculating wash liquid
apparatus for recirculating wash liquid from said wash tub to said
wash load comprising: A detection device for detecting the suds
condition of said wash liquid and outputting a signal; A control
for receiving said signal and outputting predetermined commands for
washing said fabric items, Said control including a predetermined
command for providing a pretreatment step for said wash load, all
or a portion of said pretreatment step being alterable or
terminable by said control upon said control receiving a signal
indicating a existing or potential suds lock condition.
2. A washing machine apparatus according to claim 1 wherein said
detection device comprises a pressure detection device for
determining the pressure level of the wash liquid within the
recirculating wash liquid apparatus and signaling said control when
pressure changes beyond one or more preset indicated values to
indicate suds lock.
3. A washing machine apparatus according to claim 1 wherein said
detection device comprises a device for measuring the basket speed
for determining the speed of the basket and signaling said control
when said speed changes beyond one or more preset indicated values
to indicate suds lock.
4. A washing machine apparatus according to claim 1 wherein said
detection device comprises a device for measuring basket
acceleration after the basket is brought up to normal operating
spin speed for determining the acceleration of the basket and
signaling said control when said acceleration changes beyond one or
more preset indicated values to indicate suds lock.
5. A washing machine apparatus according to claim 1 wherein said
detection device comprises a device for measuring clutch
temperature for determining the temperature of the clutch and
signaling said control when said clutch temperature changes beyond
one or more preset indicated values to indicate suds lock.
6. A washing machine apparatus according to claim 1 wherein said
detection device comprises a tachometer for determining the speed
of the motor and signaling said control when said motor speed
changes beyond one or more preset indicated values to indicate suds
lock.
7. A washing machine apparatus according to claim 1 wherein said
detection device comprises a device for measuring either current or
wattage for determining the current or wattage provided to the
motor and signaling said control when said current or wattage
changes beyond one or more preset indicated values to indicate or
predict suds lock.
8. A washing machine apparatus according to claim 1 wherein said
detection device comprises a device for measuring either current or
wattage for determining the current or wattage provided to the
washing machine and signaling said control when said current or
wattage changes beyond one or more preset indicated values to
indicate or predict suds lock.
9. A washing machine apparatus according to claim 1 wherein said
detection device comprises a device for measuring motor torque for
determining and signaling said control when said motor torque
changes beyond one or more preset indicated values to indicate or
predict suds lock.
10. A washing machine apparatus according to claim 1 wherein said
detection device comprises a device for measuring the level of suds
within said washing machine and providing a signal to said control
upon measuring a predetermined suds level.
11. A washing machine according to claim 10 wherein said device is
a conductivity strip.
12. A washing machine according to claim 10 wherein said device is
an ultrasonic emitting and detecting device.
13. A washing machine according to claim 10 wherein said device is
a light emitting and detecting device.
14. A washing machine apparatus for washing a textile wash load
having a wash tub for receiving a wash liquid within which there is
a rotatable wash zone including a peripheral wall, a motor for
rotating said peripheral wall and said wash load in said wash zone
about a predetermined axis and an apparatus for recirculating wash
liquid from said wash tub to said wash load comprising: a control
for outputting predetermined commands for washing said fabric
items, selectably controlling the on, off or on and off states of
one or more inlet valves and receiving information about the on,
off or on and off states of said valves; said control including a
predetermined command for providing a pretreatment step for said
wash load, said control being programmed to issue a command upon
said control receiving one or more signals indicating that said
inlet valves have been on, off or a combination of on and off a
predetermined time indicating suds lock or an abnormal
condition.
15. A washing machine according to claim 14 wherein said issued
command is a command to terminate a portion of said pretreatment
step.
16. A washing machine according to claim 14 wherein said issued
command is a command to discontinue adding water to said washing
machine.
17. A washing machine apparatus for washing a textile wash load
having a wash tub for receiving a wash liquid within which there is
a rotatable wash zone including a peripheral wall, a motor for
rotating said peripheral wall and said wash load in said wash zone
about a predetermined axis and a recirculating wash liquid
apparatus for recirculating wash liquid from said wash tub to said
wash load comprising: A sensor located in said washing machine for
detecting amounts of recirculating liquid and providing
corresponding signals, A control having a preprogrammed information
processor for receiving said signals and consumer input and
outputting predetermined commands comprising a cycle for washing
said fabric items, Said control having an initial cycle comprising
addition of water and providing a combined spray and spin, said
initial cycle having a portion for determining the size of the
fabric load.
18. An automatic washer according to claim 17 wherein said control
determines the size of said fabric load based on information
provided by said sensor.
19. An automatic washer according to claim 18 wherein said sensor
is a pressure sensor.
20. An automatic washer according to claim 17 wherein said cycle is
altered by said control using said fabric load information.
21. An automatic washer according to claim 17 further including an
inlet valve, wherein said control determines the size of said
fabric load using information about the on, off or on and off state
of the inlet valve.
22. An automatic washer according to claim 17 wherein said cycle is
altered by said control using said fabric load information, said
control considering said consumer input.
23. An automatic washer according to claim 21 wherein said cycle is
altered by said control using said fabric load information, said
control considering said consumer input.
24. An automatic washer according to claim 17 further including one
or more deep fill wash cycles following said initial cycle, said
deep fill wash cycles including one or more periods of fabric load
agitation, drain and spin, followed by one or more deep or spray
rinse cycles including one or more periods of fabric load
agitation, drain and spin, wherein said determined load size
information is used by said control to affect one or more portions
of said deep fill wash cycles or said deep fill or spray rinse
cycles.
25. A washing machine comprising: an imperforate wash tub, a wash
basket positioned within said wash tub defining a wash zone, a
fresh water inlet and a recirculation system comprising a
collection zone for receiving wash liquid from said wash zone and
being spaced below said wash basket, a pump having a suction inlet
communicating via a first fluid conduit with said collection zone
and a discharge outlet communicating with a recirculation nozzle
via a second fluid conduit, said nozzle being positioned to direct
wash fluid into said wash zone, a pressure dome located in fluid
connection with said pump discharge outlet and having a pressure
detection device for detecting the suds condition of said wash
liquid by determining the pressure level of the wash liquid within
the second fluid conduit and outputting a pressure detection signal
and a control for receiving said pressure detection signal and
outputting predetermined commands for washing fabric items.
26. A washing machine according to claim 25 where in the case said
pressure detection device detects a failure situation where the
desired recirculation is not satisfied, said control providing a
predetermined command for terminating all or a portion of the
cycle.
27. A washing machine according to claim 25 where in the case said
pressure detection device detects a failure situation where suds
lock exists, the control provides a predetermined command for
terminating the pretreatment step.
28. A washing machine according to claim 25 where said pressure
detection device detects load size during the pretreatment cycle
and said control provides a predetermined command to perform a
predetermined series of steps.
29. A washing machine according to claim 25 where said control
detects load size based on detected inlet on, off or on and off
time information.
30. A washing machine according to claim 25 where said control
prevents occurrence of suds lock based on detected inlet on, off or
on and off time based on said pressure sensor signaling said
control to add water.
31. A washing machine according to claim 25 where said control
determines the length of the pretreatment portion of the cycle
based on the detected load size information.
32. A washing machine according to claim 25 where said control
controls cycle processes based on load size information either
obtained from a user interface or measured during pretreatment
cycle.
33. A washing machine apparatus for washing a textile wash load
having a wash tub for receiving a wash liquid within which there is
a rotatable wash zone including a peripheral wall, a motor for
rotating said peripheral wall and said wash load in said wash zone
about a generally vertical axis and an agitator or impeller for
imparting energy to said wash load to cause rollover of said wash
load comprising: A control for receiving user input and outputting
predetermined commands for washing said fabric items, Said control
including a predetermined command where upon selection of a
predetermined high water level or detection of a large load, said
control provides for a delayed deep fill wash including a first
fill to a first predetermined level, soak, agitation or both of the
load for a first period to assist rollover followed by a second
fill within said wash tub to a higher water level.
34. A washing machine according to claim 34 where said control
performs said delayed deep fill wash upon consumer input to said
control selecting a maximum water level.
35. A washing machine according to claim 34 where said control
performs said delayed deep fill wash upon consumer input to said
control selecting a particular cycle.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to automatic washers, either
of the front-loading or top-loading types, and more particularly to
an improved washing system and control therefor.
[0002] Automatic clothes washers generally include fluid handling
systems for filling a washer tub with a wash fluid consisting of a
water and detergent solution, tumbling or agitating a wash load of
fabrics for a period of time, then draining the wash fluid from the
tub. A portion of the washing part of the cycle may include a spray
treatment or pretreatment of the fabrics while the basket is
spinning. A subsequent rinse with fresh water and draining of the
rinse water are also provided. All or part of the rinse cycle may
include a spray rinse of the fabrics while the basket is spinning
at high speed.
[0003] Spray treatment of fabrics during the wash cycle therefore
is known. Spray treatment may be desirable in a clothes washer
because of known benefits such as improved washing performance and
reduced energy and water usage. An example of a clothes washer
having spray treatment is disclosed in U.S. Pat. No. 5,271,251 for
example, assigned to the assignee of the present invention. In this
example, however, a probe sensor provides a signal for the purpose
of maintaining a predetermined water level during recirculation.
Alternatively, a pressure dome or temperature thermistor may be
used to detect the water level and a determination may be made for
the level of water to be used in the following swirl portion of the
cycle. However, there is no determination made of the amount of
fabric load contained within the washer using the on or off times
of the inlet valve or valves or the information provided by the
pressure sensor.
[0004] There are known disadvantages to spray treatment as well.
One undesirable condition which has been found to occur during a
spray pretreatment portion of the wash cycle is `suds lock`. When
this condition occurs, contact of the fluid with the spinning
basket acts to further increase the amount of suds which thus
raises the height of the sudsy fluid toward the basket. The
eventual result of this unstable process is that suds build up
beyond the bottom of the basket and climb between the sides of the
basket and tub. This large amount of suds acting between the
spinning basket and the fixed tub produces a significant drag force
on the basket. This drag force is large enough to cause the clutch
to slip and thus causing the basket to slow down considerably. This
slipping of the clutch due to excessive suds between the spinning
basket and the tub is called `suds lock`.
[0005] Certain combinations of environmental factors have been
found to increase the likelihood of suds lock. Such combinations of
very small loads or no load, very large doses of detergent, liquid
detergent, type of detergent and soft water have been found to
increase the formation of suds during the spray pretreat cycle.
Also, if the means by which the amount of water controlled during
the spray pretreatment cycle is not robust, suds lock may be more
likely. To guard against both worst case conditions or machine
degradation over time, a control for sensing suds lock and
controlling the machine based on suds lock information is
desirable.
[0006] U.S. Pat. No. 4,784,666, assigned to the assignee of the
present application, discloses a high performance washing process
for vertical axis automatic washers which includes the
recirculation of wash fluid prior to the agitate portion of the
wash cycle. That patent describes, as a particular embodiment of
the invention, to load a charge of detergent into the washer along
with a predetermined amount of water, preferably prior to admitting
a clothes load into the basket to assure that the concentrated
detergent solution will initially be held in a sump area of the
wash tub so that the detergent will be completely dissolved or
mixed into a uniform solution before being applied to the clothes
load. It is also suggested that the addition of an anti foaming
agent may be desirable. No particular arrangement is provided for
mixing the detergent and water to provide a uniform solution, nor
is any particular means described for assuring that the amount of
wash liquid within the tub during the spin wash portion of the wash
cycle is an appropriate amount which is slightly in excess of the
saturation level for the clothes load.
[0007] U.S. Pat. Nos. 5,219,370 and 5,233,718, assigned to the
assignee of the present invention, disclose variations on a high
performance washing process for vertical or horizontal axis
automatic washers which include the recirculation of wash fluid
prior to the agitate portion of the wash cycle or other washing or
rinsing steps. The primary means for controlling water input into
the systems is to detect water level using a liquid level sensor.
It is suggested that a pressure dome sensor may be used to detect
an oversudsing condition, however this would be performed in
conjunction with usage of the liquid level sensor, which is not
provided for in the present invention. These patents allow for the
possibility of indirectly inferring the water level in the tumble
portion of the cycle based on the sensed level of detergent liquor
in the pretreatment portion, unlike the present invention which
determines the amount of clothes load and possibility of suds
lock.
SUMMARY OF INVENTION
[0008] The present invention provides a control for sensing the
state of the washing machine during a pretreatment cycle having a
combined spray and high speed spin. During such a pretreatment
cycle the washer is susceptible to the possible occurrence of a
suds lock condition, which may be detected and handled by the
present invention. This can be accomplished by a variety of sensing
techniques, through which the possible or imminent occurrence of
suds lock can be determined or inferred, including sensing the
condition of the wash liquid or the washing machine components. A
suds lock condition may even be anticipated and avoided by the
present invention. Further, by knowing that a suds lock condition
is occurring or is likely to occur, the spray pretreatment portion
of the wash cycle can be preterminated and the rest of the cycle
can be continued. Alternatively, adding of water may be
discontinued. By following a suds lock condition immediately with a
deepfill of the tub of the automatic washer, suds buildup within
the basket can be minimized.
[0009] By using the same technique of measuring suds lock, the size
of the load can also be ascertained. This information can thus be
applied to control the rest of the cycle. For example, the
automatic deepfill water level and relative agitation rate can be
altered according to the sensed size of the load. In the present
invention, the load size is determined regardless of the types of
fabric materials contained in the load. As well, in certain load
conditions such as large loads, the deepfill portion may be
slightly altered in order to optimize and maximize the wash
performance. This may be performed not only as a result of
detecting the load size but also as a result of user control
inputs.
[0010] Furthermore, the control may be used to detect special
conditions, for example unusually wet laundry at the outset of the
wash cycle or failure in some aspect of the wash cycle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a perspective view of a partially cut away
automatic washer containing recirculation hardware embodying the
principles of the present invention.
[0012] FIG. 2 is a schematic diagram of an automatic washer
portraying in fluid circuit form the recirculation hardware and
control arrangement embodying the principles of the present
invention.
[0013] FIG. 3 is a block diagram of the process for controlling the
spray pretreatment portion of the wash cycle based on monitoring
the condition of suds lock occurrence.
[0014] FIG. 4a is a block diagram of an automatic washer containing
recirculation hardware using flow rate information to control the
amount of water added during the spray pretreatment portion of the
wash cycle.
[0015] FIG. 4b is a block diagram of an automatic washer containing
recirculation hardware using height of water in the tub sump
information to control the amount of water added during the spray
pretreatment portion of the wash cycle.
[0016] FIG. 5 is a plot displaying the typical form by which the
inlet valve is controlled based on measured information.
[0017] FIG. 6 is a block diagram of the general process for
determining whether suds lock has occurred based on criteria and
suds lock measure information.
[0018] FIG. 7 is a block diagram that shows the components which
make up the drive system and the corresponding means for measuring
the existence of suds lock through each component.
[0019] FIG. 8 is a block diagram that shows the measuring of the
existence of suds lock through measuring the height of suds in the
tub/basket.
[0020] FIG. 9 is a plot displaying the process by which the inlet
valve is controlled based on measured information for the special
case of having too much added water in the system at the start of
the cycle.
[0021] FIG. 10 is a plot displaying the process by which the inlet
valve is controlled based on measure information for the special
case of never satisfying the measure due to some failure condition
in the machine.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] FIG. 1 a washing machine is generally shown at 10 which has
a tub 12 with a vertical agitator 14 therein, a water supply 15, a
power supply (not shown), an electrically driven motor 16 operably
connected via a transmission 20 to the agitator 14 and controls 18
including a presettable sequential control device 22 for use in
selectively operating the washing machine 10 through a programmed
sequence of washing, rinsing and extracting steps. A water level
setting control 18 is provided for use in conjunction with control
device 22. A fully electronic control having an electronic display
(not shown) may be substituted for control device 22. The control
device 22 is mounted to a panel 24 of a console 26 on the washing
machine 10. A rotatable and perforate wash basket 28 is carried
within the tub 12 and has an opening 36 which is accessible through
an openable top lid 30 of the washer 10. Tub ring 37 is positioned
overlying wash basket 28 and tub 12.
[0023] The invention disclosed herein is not necessarily limited to
implementation in a vertical axis washing machine as shown in the
figures. Inasmuch as the invention is a washing machine having a
unique control and recirculating spray wash arrangement, the
invention may be equally applied in a horizontal or tilted axis
washing machine. Moreover, in the specific application of the
invention in a vertical axis washing machine, the invention may be
practiced in a variety of machines which may include different
motor and transmission arrangements, pumps, recirculation
arrangements, agitators or impellers, or controls.
[0024] A sump hose 40 is fluidly connected to a sump (not shown)
contained in a lower portion of tub 12 for providing a wash fluid
recirculating source. Pressure dome 42 receives the recirculating
fluid which exits via recirculating spray nozzle hose 48 which is
fluidly connected to recirculating spray nozzle 32. A pressure
sensor or transducer 46 detects fluid pressure within pressure dome
42 and provides an output signal via lines 47 to the control, the
signal varying dependent upon the sensed dynamic pressure. A second
air dome 50 having a deepfill pressure sensor or transducer
optionally provides a second pressure signal indicating static
pressure to the control via lines 52.
[0025] As described herein, a pressure sensor may be a pressure
switch having predetermined pressure levels that, within certain
limits, will provide one or more signals to control 22 that a
certain pressure has been achieved. Depending on the presence or
absence of such signals, the control will receive and store or
process such information, as is well known. Alternatively, a
transducer may be used to sense pressure and provide a signal of
varying frequency or voltage to control 22 indicating the pressure
levels detected.
[0026] In FIG. 2 a schematic diagram further describes an example
of a washing machine incorporating the present invention. Hot water
inlet 11 and cold water inlet 13 are controlled by hot water valve
17 and cold water valve 19, respectively. Valves 17 and 19 are
selectably openable to provide fresh water to feed line 60. A spray
nozzle valve 21 is fluidly connected to feed line 60 for selectably
providing fresh water to tub 12 when desired. This fresh water is
delivered by fresh water spray nozzle 31 via fresh water hose 33.
Valves 17 and 19 are openable individually or together to provide a
mix of hot and cold water to a selected temperature.
[0027] Upon opening one or both of valves 17 and 19, fresh water is
selectably provided to a series of dispenser valves via feed line
60. Valve 62 selectably provides fresh water to detergent dispenser
63, valve 64 selectably provides fresh water to bleach dispenser
65, and valve 66 selectably provides fresh water to softening agent
dispenser 67.
[0028] As further shown in FIG. 2, the washing machine includes a
wash liquid recirculation system. In order to recirculate wash
liquid for the recirculating spray wash, tub sump 41 collects wash
liquid and is fluidly connected to pump 23 by sump hose 40. Pump 23
is selectably operational to pump liquid from tub sump 41 via pump
outlet hose 25 either to recirculating hose 27 or drain hose 29
depending on the position of bidirectional valve 30. Recirculating
hose 27 provides recirculating wash liquid to pressure dome 42, the
wash liquid exiting the pressure dome 42 via recirculating spray
nozzle hose 48 and being emitted to the wash basket 28 via
recirculating spray nozzle 32.
[0029] Pressure dome 42 provides a head of pressure varying
dependent upon the amount of wash liquid contained in the
recirculating wash system by maintaining a captured dome of air in
communication with the recirculating wash liquid. The pressure dome
42 provides a channel for the captured air to keep in contact with
pressure sensor 46 via pressure line 45.
[0030] Pressure sensor 46 provides optionally either an on/off or a
varying or dynamic signal to control 22 via lines 47, the signal
varying dependent on the sensed pressure of the recirculating wash
liquid. Control 22 also optionally receives a static pressure
signal from deepfill transducer dome 50 via lines 52 for signaling
the level of wash liquid within wash tub 12, however the invention
disclosed herein may be practiced without use of a deepfill
pressure dome. Control 22 is further operable to receive input
signals via lines 49, including signals from valves 21, 62, 64 and
66 providing on and off times for these valves.
[0031] By sensing the air pressure within pressure dome 42, the
amount of recirculating wash liquid in the washing machine may be
inferred. This information is useful to determine the amount of
free water in the washing machine during a recirculating wash.
Thereby, the amount of clothing in the washing machine may be
inferred, which information is useful in order to minimize water
and energy usage during a spray pretreatment cycle, stain cycle or
other recirculating wash cycle, and further during later or other
portions of the cycle. Also, the suds lock condition, or absence
thereof during portions of a cycle may be determined. Suds lock may
be prevented by limiting recirculating wash liquid to slightly in
excess of clothes saturation.
[0032] A basic process for the new control scheme of the spray
pretreatment portion of the wash cycle is shown in the block
diagram 100 in FIG. 3. The process begins at the commencement of
spray treatment 102 by starting monitoring of the suds lock
algorithm 104. The process simply either completes the full cycle
if suds lock does not occur or skips through the rest of the
pretreatment cycle and onto the next step 106 in the case that suds
lock should occur. This process 100 is independent of the method by
which the existence of suds lock is determined.
[0033] Several methods can be applied in order to ascertain the
existence of suds lock. FIG. 4a displays a block diagram 108 of the
automatic washer containing recirculation hardware where a measure
based on the flow rate of the wash liquid recirculation line is
used to ascertain when water is added to the recirculation system.
The flow rate can be measured in one of a number of known ways. A
flow washer 68 contained in detergent dispenser valve 63 controls
the flow rate within a predetermined range for a variety of
predictable inlet water pressures. Limiting flow in this manner
allows the flow rate to be inferred based upon the on time of the
inlet valve. A flow meter may also be used. Finally, the deep fill
rate may also be discerned.
[0034] This intermittent process is due to the dry clothes load
absorbing water into the load and thus the system requiring more
water to regain the necessary flow rate. A similar approach shown
in a block diagram 110 in FIG. 4b to determine when water needs to
be added to the system can be performed by any of various
techniques capable of measuring the height of the wash fluid in the
sump portion of the tub. Alternatively, a pressure sensor may be
used to determine whether one or more predetermined pressure levels
have been reached. In either case, if the control determines that
the necessary wash fluid amount recirculating within the washer is
satisfied, the control discontinues adding water by intermittent
opening of the water inlet valve.
[0035] Detecting Load Size During Pretreatment Portion of Cycle
Using either of these means shown in FIGS. 4a or 4b to control the
process of adding water to the system, an alternating pattern of
the times for the addition of water to the system and not adding
water to the system can be gained. FIG. 5 shows such a typical
pattern or profile 112 relating to the on and off periods of the
inlet valve for the spray pretreatment portion of the automatic
wash cycle, based on whether the water level or water pressure
detecting means is satisfied. Preferably, the control determines
the necessary amount of wash liquid as that amount which is
slightly in excess of the saturation level for the clothes
load.
[0036] Accordingly, as the pretreatment portion of the cycle
proceeds as shown in FIG. 5, the control continually monitors the
inlet on or off times or both on and off times, or the pressure or
water level signals which are used to control the inlet on, off or
on and off times. This information, as discussed later herein, may
be used to determine whether the clothes washer is experiencing a
suds lock condition or some other abnormal condition if the
information is outside a certain expected range. As well, however,
this information may be used to determine the load size being
washed, so that the pretreatment cycle and later portions of the
wash cycle may be altered and preferably optimized or adapted to
effectively complete the cleaning and rinsing of the clothes, but
no more in order to avoid suds lock.
Pretreatment Cycle Control Based on Load Size Measurement
[0037] By using the measure of load size during the pretreatment
cycle, the rest of the pretreatment cycle can be optimized based on
the load size information. After the desired water level or
pressure is detected as initially satisfied by the control 22, the
washing machine is allowed to continue the normal pretreatment
cycle where water is added to the system as requested by the
control system for a first predetermined time. The control then
identifies the load size in a manner as previously discussed. The
inlet valve may be shut off regardless of whether water is called
for by the control system when a second predetermined time is
reached. This second predetermined time may be defined based on the
load size measure. At this time, the pretreatment step is completed
and the machine proceeds through the rest of the cycle. The process
of not adding water will aid the system in avoiding suds lock which
increases the performance of the cycle.
[0038] In another example of optimizing the rest of the
pretreatment cycle based on the load size information, the control
system determines the total water fill times at preselected
intervals. Depending on the total water fill time, a preselected
overall cycle time for pretreatment is performed, during which
water may be added. The cycle is further optimized by taking into
consideration the water level and cycle selected by the user, so
that the washer may perform not only according to the load size
detected but in accordance with the demands of the user.
Total Cycle Control based on Load Size Measurement
[0039] From the various means of determining load size during the
pretreatment portion of the cycle, this information can be applied
to control other portions of the cycle. In previous washers, the
load size or water level input on the console is the input used to
control the amount of water added to the system in the deep fill
and the relative agitation rate based on the type of cycle chosen.
In the present invention, the load size determined from the
pretreatment step can be applied in a similar way to determine
water amounts and control the agitation performed during the rest
of the wash cycle. For example, the load size information can be
used to determine the agitation length and rate, to determine the
deep fill wash length, spin time and speed, the deep fill or spray
rinse length, spin time and speed, or the number of rinses.
[0040] An automatic washer incorporating the present invention may
preferably include traditional user control inputs such as cycle,
water temperature and water level. Although the input by the
consumer may be taken into consideration to affect the cleaning
cycle, the control selectively processes the previously mentioned
inlet on, off or on and off, water level or pressure information
independently of such user input to determine the size of the
clothes load. It is noted that the type of clothes, particularly
the variety of materials providing the makeup of the clothes is not
of critical importance once the pretreatment cycle is completed,
since the load size information gained during the pretreatment
cycle is all that is needed to continue the wash process. However,
the user input may be considered as part of an algorithm such that
the performance of the washer, for example the length of wash time,
is not greatly different than consumer expectations for a selected
input.
[0041] In another example of optimizing the rest of the wash cycle
based on detected load size, it is a known problem in a vertical
axis washer to turn over a large clothes load approaching 17 pounds
during a deep fill wash. One difficulty is that after filling the
washer to the maximum level and beginning agitation, the large
items in the load such as sheets, tablecloths or towels may be
displaced above the waterline by the agitator, which physically
lowers the water level in the tub. The lowering of the water level
in the tub can be anticipated by control 22 or detected via a
pressure sensor 46 or 50 and compensated for by adding water to
return to the maximum level.
[0042] Alternatively, to address the aforementioned problem, a
delayed fill may be used. When the user selects a heavy duty cycle
along with maximum water level, for example the water level in the
deep fill wash is initially brought to a level slightly below the
maximum. The clothes load will be partially submerged, with a
portion of the load remaining dry or at most partially saturated on
the surface. At this water level, the agitator is allowed to
commence turning and will easily pull the dry clothing from the top
of the load, moving the clothes down the center of the basket and
up the outside in the normal motion. After an initial preselected
period, long enough to allow the load to be fully wetted and
largely submerged, the washing machine may be filled to the maximum
level followed by additional agitation or while continuing to
agitate. The preceding process assures that normal rollover of the
wash load is achieved as quickly as possible despite the large
load.
Suds Lock Measuring
[0043] FIG. 6 displays a block diagram 118 of the general process
for determining whether suds lock has occurred based on selected
criteria and suds lock measure information. This diagram is
independent of chosen measurement technique. Several sets of
criteria are satisfactory for the case of using information about
the inlet water valve cycling information measurement of suds lock.
The following table contains several functional criteria:
1TABLE Suds Lock Criteria Table for Inlet Water Valve Based
Measures. Suds Lock Measure Suds Lock Criteria Case (1) t.sub.on(0)
10-20 sec. Case (2) t.sub.on(0)/(t.sub.on(1)) N Case (3)
t.sub.on(0)/(t.sub.on(1) + t.sub.on(2)) N Case (4)
t.sub.on(O)/(t.sub.on(1) + t.sub.on(2) + t.sub.on(3)) N As part of
the suds lock criteria, note that if t.sub.on(2), t.sub.on(3) = 0,
then let t.sub.on(2) = t.sub.on(3) = t.sub.on(1).
[0044] The optimum value for N is approximately 2. The algorithm
also incorporates a minimum time, t.sub.min.sub..sub.--.sub.check,
which to start checking for suds lock to occur. This time could be
set between 0 sec and 40 sec. In addition to satisfying the suds
lock criteria, there also is a time t.sub.on.sub..sub.--.sub.min
which sets a minimum time of addition which it must be above to be
considered as suds lock condition. Typical ranges for this are
between 2 to 4 sec.
[0045] Other ways exist for detecting suds lock in the washing
machine. FIG. 7 displays a block diagram 120 that shows the
components which make up the drive system and the corresponding
means for detecting the existence of suds lock through each
component. For the basket, the means for detecting the existence of
suds lock 122 may be summarized as follows.
[0046] A first suds lock detection method is by measurement of the
basket RPM (by magnetic, optical or ultrasonic means) after the
basket is brought up to normal operating speed. When basket reduces
RPM by 70% from the steady state value, suds lock has occurred.
[0047] A second suds lock detection method is by measurement of the
basket or tub acceleration after the basket is brought up to normal
operating speed. Vibration of the basket or tub should be fairly
constant or increasing during the spray pretreatment portion of the
cycle unless suds lock occurs.
[0048] For the drive system, the means for detecting the existence
of suds lock 124 may be summarized as follows.
[0049] A first suds lock detection method is by measuring the
temperature of the clutch. When a suds lock condition occurs, the
temperature of the clutch will increase significantly during suds
lock condition. A second suds lock detection method is by measuring
torque on drive components. When a suds lock condition occurs, a
significant drop in torque will occur.
[0050] For the motor, motor control and supply power, the means for
detecting the existence of suds lock 126, 128 and 129 may be
summarized as follows. A first suds lock detection method is by
measurement of motor RPM using a tachometer which is built into the
motor. When the basket reduces RPM by 70% from steady state value,
suds lock has occurred. A second suds lock detection method is by
measurement of the current or wattage going to the motor measured
at motor. When current or wattage increase by a given percentage,
suds lock has occurred.
[0051] A third suds lock detection method is by measurement of
total current or wattage going to the entire machine, since motor
current is by far most significant component. When current or
wattage increase by a given percentage, suds lock has occurred. A
fourth suds lock detection method is by measurement using an opto
coupler for obtaining information about drop in the torque draw of
the motor. A fifth suds lock detection method is by measurement
using a ferrite core sensor for obtaining information about the
drop in the torque draw of the motor. In the latter two methods,
when torque drops by a given amount, suds lock has occurred.
[0052] In addition to measurements which can be made on the drive
system, measurement of the height of the suds in the system can be
made. FIG. 8 displays a block diagram 130 illustrating the
components which are to be observed, that is the tub or the basket,
and the means for detecting the existence of suds lock through each
component. Specific embodiments of such techniques to measure the
height of the suds during a spray pretreatment portion of the wash
cycle may include a) providing a conductivity strip along the side
of the basket; b) ultrasonic measurement, or c) optical
measurement. Feedback provided to the control in each case
indicates an oversuds condition, from which it may be inferred that
suds lock has occurred.
Special Conditions
[0053] In addition to the occurrence of suds lock, there are a few
special conditions which can as be detected by the control.
Although other detection means may be used, in these examples the
control monitors the inlet valve on time over a prescribed check
time. One such condition occurs when the machine is started in
pretreatment portion of the cycle with much more water than
necessary. FIG. 9 displays the process by which the inlet valve is
controlled based on measure information for the special case of
having too much added water in the system at the start of the
cycle. This condition can occur for the reasons that the user
starts the machine into normal deepfill (without prefill), then
stops the machine after a good amount of water has filled the
machine (over 2 gallons) and the machine is switched and restarted
in pretreatment cycle; the user puts a very soggy clothes load into
the machine or the user physically adds water into the machine with
the load.
[0054] For all these conditions, the time by which the machine
calls for water will be very small. Thus by monitoring the time by
which the control system calls for water with respect to some
length of checking time, this condition can be ascertained. If such
a case should occur, the pretreatment cycle may be ended and the
rest of the cycle is continued.
[0055] Another special condition can be detected by the primary
means of monitoring the inlet valve on time over a prescribed check
time. One such condition may occur when the washing machine is in
the recirculating spray pretreatment portion of the cycle and the
machine continuously calls for water without stopping.
[0056] FIG. 10 displays a graphic depiction 140 of the process by
which the inlet valve is controlled based on measured information
in the special case where the recirculation flow in the system at
the start of the cycle is not satisfied for some finite period of
time. In addition to sensing this condition based on the
recirculation flow being not satisfied, additional information can
be gained from the deepfill pressure transducer for the air dome 50
in the tub.
[0057] For the case where the deepfill pressure transducer does not
sense the existence of a sizable amount of water in the tub, a
variety of machine conditions may be a cause. Under the category of
washing machine component failures, the failures can include a
sizable leak in the tub or the recirculation or drain hose system;
one or more bad inlet valves not adding water to system, or a
recirculation diverter valve failed or stuck in the drain
direction. Under the category of non-washing machine component
failures might be a long fill due to very low line pressure.
[0058] For the case where the deepfill pressure transducer is
sensing the existence of a sizable amount of water in the tub, the
following machine conditions may be a cause, all of which are
washing machine component failures. The failures can include a bad
recirculation pressure switch, a pump or motor failure, a severe
recirculation line clog or the recirculation pressure hose is
disconnected.
[0059] In case of such failure, the control 22 will end the cycle
and indicate the failure condition to the consumer.
[0060] As is apparent from the foregoing specification, the
invention is susceptible of being embodied with various alterations
and modifications which may differ particularly from those that
have been described in the preceding specification and description.
It should be understood that we wish to embody within the scope of
the patent warranted hereon all such modifications as reasonably
and properly come within the scope of the contribution to the
art.
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