U.S. patent application number 15/862680 was filed with the patent office on 2018-05-10 for ice maker with piezo dielectric elastomer sensor.
This patent application is currently assigned to WHIRLPOOL CORPORATION. The applicant listed for this patent is WHIRLPOOL CORPORATION. Invention is credited to ALBERTO R. GOMES, YEN-HSI LIN, ANDREW M. TENBARGE.
Application Number | 20180128531 15/862680 |
Document ID | / |
Family ID | 52581260 |
Filed Date | 2018-05-10 |
United States Patent
Application |
20180128531 |
Kind Code |
A1 |
GOMES; ALBERTO R. ; et
al. |
May 10, 2018 |
ICE MAKER WITH PIEZO DIELECTRIC ELASTOMER SENSOR
Abstract
An ice maker includes, among other things, an ice cube mold, an
ice cube remover and a force sensor comprising a piezo dielectric
elastomer (PDE). The ice cube mold has at least one cavity for
receiving liquid. The ice cube remover is configured to apply a
removal force to either the mold or an ice cube. The force sensor
is provided on either the mold or the remover and provides an
output indicative of the removal force. Upon the removal of an ice
cube from the cavity, the ice cube remover applies a removal force
to the mold or the ice cube to effect the removal of the ice cube
from the cavity and the force sensor outputs a signal indicative of
the removal force.
Inventors: |
GOMES; ALBERTO R.; (CUMMING,
GA) ; LIN; YEN-HSI; (SAINT JOSEPH, MI) ;
TENBARGE; ANDREW M.; (SAINT JOSEPH, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
WHIRLPOOL CORPORATION |
BENTON HARBOR |
MI |
US |
|
|
Assignee: |
WHIRLPOOL CORPORATION
BENTON HARBOR
MI
|
Family ID: |
52581260 |
Appl. No.: |
15/862680 |
Filed: |
January 5, 2018 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
14476796 |
Sep 4, 2014 |
9863684 |
|
|
15862680 |
|
|
|
|
61873911 |
Sep 5, 2013 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F25C 5/06 20130101; F25C
2600/04 20130101; F25C 2700/00 20130101 |
International
Class: |
F25C 5/06 20060101
F25C005/06 |
Claims
1. An ice making assembly comprising: an ice maker having an output
for expelling ice cubes; a storage bin defining an ice cube
reservoir and having an opening in communication with the ice maker
output; and a weight sensor comprising a piezo dielectric elastomer
(PDE) provided below the storage bin and outputting a signal
indicative of the weight of the ice cubes within the reservoir;
wherein ice cubes expelled from the ice maker are received through
the opening and stored in the ice cube reservoir, with the weight
sensor providing an output indicative of the weight of the ice
cubes within the reservoir.
2. The ice making assembly of claim 1, wherein the ice maker is
located higher than the storage bin.
3. The ice making assembly of claim 2, wherein the opening is in a
top of the storage bin.
4. The ice making assembly of claim 3, wherein the output does not
overlie the opening.
5. The ice making assembly of claim 1, wherein the weight sensor is
attached to a storage bin mounting plate.
6. The ice making assembly of claim 5, wherein the storage bin is
removable from the storage bin mounting plate.
7. The ice making assembly of claim 5, wherein the storage bin
compresses the weight sensor when the storage bin is placed onto
the storage bin mounting plate.
8. The ice making assembly of claim 1, wherein the ice maker expels
ice cubes when the weight sensor output is within a pre-specified
range.
9. The ice making assembly of claim 8, wherein the pre-specified
range is based in part on a user input.
10. The ice making assembly of claim 9, wherein the user input
selects an amount of ice available in the storage bin wherein a
selected amount of ice is less than a maximum amount of ice that
the storage bin will hold.
11. The ice making assembly of claim 1, wherein the ice maker
expels ice cubes when the weight sensor output is below a
pre-specified value.
12. The ice making assembly of claim 1, wherein the ice maker
expels ice cubes when the weight sensor output is equal to or below
a pre-specified value.
13. The ice making assembly of claim 1, wherein the ice maker
expels ice cubes when the weight sensor output is above a
pre-specified value.
14. The ice making assembly of claim 8, wherein the pre-specified
range is based in part on a capacity of the storage bin.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This Application represents a divisional application of and
claims priority to U.S. patent application Ser. No. 14/476,796
entitled "Ice Maker with Piezo Dielectric Elastomer Sensor", filed
Sep. 4, 2014, currently allowed, and further claims priority to and
the benefit of U.S. Provisional Patent Application Ser. No.
61/873,911, filed on Sep. 5, 2013, the entire disclosures of which
are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] The freezer compartment of a residential refrigerator may
include an automatic ice maker. An ice maker typically includes an
ice mold for receiving water and forming ice cubes while the water
freezes. Once the molded ice cubes are frozen, a motor either
twists the ice mold or rotates an arm to eject the ice cubes out of
the mold. The ejected ice cubes may then collect in a bin until
dispensed from the freezer compartment.
SUMMARY OF THE INVENTION
[0003] The invention relates to an ice maker comprising: an ice
cube mold having at least one cavity for receiving liquid; an ice
cube remover configured to apply a removal force to at least one of
the mold and ice cube; a force sensor comprising a piezo dielectric
elastomer (PDE) provided on one of the mold and remover and
providing an output indicative of the removal force; wherein upon
the removal of an ice cube from the cavity, the ice cube remover
applies a removal force to one of the mold and ice cube to effect
the removal of the ice cube from the cavity and the force sensor
outputs a signal indicative of the removal force.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] In the drawings:
[0005] FIG. 1 is a front view of a refrigerator with an ice maker
according to an embodiment of the invention.
[0006] FIG. 2 is a front view of an ice maker that twists an ice
cube mold to remove ice cubes according to an embodiment of the
invention.
[0007] FIG. 3 is an overhead view of an ice cube mold for an ice
maker with a force sensor positioned along the side edge of the
mold according to an embodiment of the invention.
[0008] FIG. 4 is an overhead view of an ice cube mold for an ice
maker with a force sensor positioned between cavities of the mold
according to an embodiment of the invention.
[0009] FIG. 5 is a front view of an ice maker that twists a rake to
remove ice cubes from an ice cube mold according to an embodiment
of the invention.
[0010] FIG. 6 is side view of a rake for ice cube removal with a
force sensor positioned along the shaft of the rake according to an
embodiment of the invention.
[0011] FIG. 7 is a side view of a rake for ice cube removal with an
array of force sensors positioned along the fingers of the rake
according to an embodiment of the invention.
[0012] FIG. 8 shows a side view of a portion of refrigerator with a
door having a ledge on which the ice storage bin may rest according
to an embodiment of the invention.
[0013] FIG. 9 is a front view of an ice bucket in contact with a
force sensor for determining the weight of the ice in the bucket
according to an embodiment of the invention.
DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0014] Three basic configurations of refrigerators with a freezer
compartment include a side-by-side configuration, a top freezer
configuration and a bottom freezer configuration. As shown in FIG.
1, a refrigerator 10 in a side-by-side configuration has a freezer
compartment 12 located next to a refrigerated compartment 14. By
contrast, a top freezer configuration has a freezer compartment
located above the refrigerated compartment and the bottom freezer
configuration has a freezer compartment located beneath the
refrigerated compartment. Generally, an ice maker 16 and an ice
storage bin 22 are located in the freezer compartment 12 of the
refrigerator 10. However, hybrid combinations of the basic
configurations may include a French door configuration where the
ice maker 16 may be included in the refrigerated compartment.
[0015] The ice maker 16 may mount to the wall 18 of the freezer
compartment 12. Alternatively, the ice maker 16 may mount to the
door 20 of the freezer compartment 12 or attach to a base 24 that
in turn may mount to the wall 18 or door 20 of the freezer
compartment 12. The ice storage bin 22 is configured to receive and
then store ice ejected from the ice maker 16 and may be positioned
on the door 20 or beneath the ice maker 16 in the freezer
compartment 12.
[0016] Referring now to FIG. 2, the ice maker 16 may further
include an ice cube mold 100 for receiving water and forming ice
cubes, a motor 102 for delivering torque to remove the ice cubes
during the ice harvesting process and a controller 104. The
controller 104 may control aspects of the ice harvesting process
including when and to what level application of motor torque to
remove ice cubes is required. The ice maker 16 may be configured as
a twist ice maker to remove ice cubes by twisting the ice cube mold
100. Alternatively, as described below, the ice maker may be
configured to remove ice cubes by rotating the fingers of a rake
through the portions of the ice cube mold containing the ice
cubes.
[0017] Referring now to FIG. 3, an ice cube mold 100 for a twist
ice maker with a force sensor 112 positioned along the side edge
114 of the ice cube mold 100 may now be described. The ice cube
mold 100 may have one or more cavities 116 for receiving liquid.
For a twist ice maker, the ice cube mold 100 may be rotatably
mounted to a drive mechanism that may apply a removal force to the
ice cubes in the flexible ice cube mold 100. For example, the ice
cube mold 100 of a twist ice maker may be supported for rotation
about a longitudinal axis 118 by a driver coupling 120 at one end
122 of the mold and a suitable shaft 124 at the opposite end 126 of
the mold. An automatically controlled motor 102 may be configured
to apply a torque to the driver coupling 120 to effect
rotation.
[0018] During an ice harvesting operation, rotation of one end 122
of the ice cube mold 100 without concurrent rotation of the
opposite end 126 may effect a twisting of the ice cube mold 100 to
a level that frees previously formed ice cubes in the cavities 116.
When the ice cube mold 100 reaches a sufficient angle of twist to
effect full ice extraction, an element 128, such as a boss located
on the ice cube mold 100, may activate a momentary switch by
physical contact. The element 128 may be located at any point on
the ice cube mold 100 where the deflection of the element 128
correlates to the overall twisting of the ice cube mold 100. For
example, as shown in FIG. 3, the element 128 may be placed along
the end 122 of the mold nearest to the driver coupling 120, though
other positions on the mold may be used.
[0019] Automatic ice makers do not typically include a feedback
mechanism to control the amount of torque generated by the motor
102 for extracting ice cubes from the ice cube mold 100. Excess
friction between one or more of the ice cubes and the cavities 116
in the ice cube mold 100 may prevent an ice cube from ejecting from
the ice cube mold 100 without the addition of more force.
Consequently, elements of the ice maker that are subject to the
application of the additional force may experience fatigue and
failure.
[0020] To provide feedback indicative of the level of force being
applied to various elements of the ice maker, particularly to the
elements actuated during an ice cube harvesting operation, a sensor
112 capable of outputting an electrical signal indicative of an
applied mechanical force may be provided. Generally, sensors that
convert mechanical force into electrical signals are known as
electromechanical transducers. A force sensor for elements of an
ice maker may be subject to large angles of deflection and high
values of strain. Namely, a sufficient angle of twist for an ice
cube mold to induce a level of torsion that will eject ice cubes
typically ranges from 20 to 40 degrees. Due to these operating
characteristics, a particularly relevant type of electromechanical
transducer for use as a force sensor is a piezo dielectric
elastomer (PDE).
[0021] PDEs are a type of dielectric electroactive polymer (DEP).
Generally, DEPs are materials in which actuation is caused by
electrostatic forces between two electrodes which squeeze the
polymer. PDEs are capable of very high strains and are
fundamentally a capacitor that changes capacitance when a voltage
is applied by allowing the polymer to compress in thickness and
expand in area in response to an electric field. DEPs require no
power to keep the actuator at a given position. Because of the
highly flexible nature of DEP, PDEs may be used as sensors for
measuring an applied force in an environment where significant
deformation may occur that would render conventional transducers
inoperative.
[0022] With the use of PDE force sensors, the applied motor torque
may be monitored and managed in a controlled fashion to aid in the
ice harvesting process. As shown in FIG. 3, implementing a PDE as a
force sensor 112 on the ice cube mold 100 may provide a feedback
mechanism for the controller 104 to detect excessive twisting of
the ice cube mold 100 and prevent early fatigue. The force sensor
112 may induce a voltage in response to the degree of deformation
of the ice cube mold 10 along the area of the ice cube mold 10 in
contact with the force sensor 112. Placing the force sensor 112 in
an area where the ice cube mold 100 has an elevated risk of
fracturing may provide actionable feedback for determining when a
particular area of the ice cube mold 100 is excessively twisted.
Therefore, conventional actuation of a momentary switch may provide
a measure of detection for achieving sufficient twist to release
the ice cubes and the PDE force sensor 112 may provide an
additional measure to help prevent excessive twisting in a specific
area prone to fatigue.
[0023] While the force sensor 112 as shown in FIG. 3 is placed
along the side edge 114 of the ice cube mold 100 proximal to the
driver coupling 120 and orthogonal to the longitudinal axis 118,
other configurations are contemplated. Non-uniform deformation of
the ice cube mold 100 in response to an applied removal force may
result from a number of diverse causes that may have different
effects on different areas of the ice cube mold 100. For example,
calcium deposits forming on the ice cube mold 100 may cause the ice
cubes to stick inside the ice cube mold 100 during the ice
harvesting process. However, the extent to which the ice cubes
stick may vary between cavities 116 resulting in variable levels of
strain between each cavity 116. Consequently, as shown in FIG. 4,
the PDE force sensor 130 may be placed between two of the cavities
116. Multiple twist sensors 112 may be implemented for monitoring
multiple high risk areas. For example, a force sensor 112 may be
placed between each pair of cavities 116. Alternatively, the PDE
force sensor 112 may be oriented at an angle relative to the
longitudinal axis 118. Preferably, the force sensor 112 may be
located at any position and orientation on the ice cube mold 100
where excessive twisting may occur as a result of a non-uniform
deformation of the ice cube mold 100.
[0024] The ice cube mold 100 may be formed of any material that is
both flexible and has a thermal conductivity conducive to forming
ice. For example, aluminum has a thermal conductivity much higher
than water and therefore aids in producing ice quickly. Other
materials contemplated for the ice cube mold generally include
plastics and metals. The material used for the ice cube mold and
its corresponding properties may directly affect the preferred
placement of the one or more force sensors. Other factors may
include the shape and relative placement of the cavities of the ice
cube mold 100.
[0025] Referring now to FIG. 5, as an alternative to twisting the
ice cube mold 100, the ice maker 16 previously described in FIG. 2
may further include a rake 200 whereby the controller 104 may
direct the motor 102 to rotate the rake 200. To expel ice cubes
from the ice cube mold 100, each finger 212 of the rake 200 is
rotatable through a cavity 116 of the ice cube mold 100.
[0026] As seen in FIG. 6, the rake 200 may further include a
rotatable shaft 210 and at least one finger 212 extending from the
shaft 210. The rotatable shaft 210 may be coupled to the motor 202
such that torque may be applied to the shaft 210 to effect rotation
during an ice harvesting process.
[0027] During an ice harvesting process with a rotating rake 200, a
heating element connected to the ice cube mold 100 may apply heat
to the cavities 116. Then, the rake 200 may rotate the fingers 212
through the briefly heated cavities 116 and effect removal of the
ice cubes. Similar to the twisting of the ice cube mold 100, the
process of rotating the fingers 212 of the rake 200 through the
cavities 116 may apply an excessive level of force to the ice cubes
causing either the ice cubes to break or elements of the rake 200
to fatigue. Additionally, undesirable levels of noise may occur
during the ice harvesting process. By implementing a PDE force
sensor 214 on the rake 200 in a manner similar to that described
above for the ice cube mold 100, a controlled application of torque
from the motor 102 to rotate the rake 200 may mitigate deleterious
effects including broken ice, rake fatigue and excess noise.
[0028] For example, as shown in FIG. 6, placing the PDE force
sensor 214 directly on the rotatable shaft 210 of the rake 200, the
applied motor force may be monitored and limited until the bond
between the ice cubes and the cavities 116 is broken. In this way,
a more gentle ice harvest may mitigate the previously described
negative effects. While the PDE force sensor 214 may extend along
the rotatable shaft 210 for a distance at least as great as two
adjacent fingers 212, other lengths may be contemplated. For
example, the PDE force sensor may extend the entire length of the
rotatable shaft 210. Similar to placing the PDE force sensor on the
ice cube mold 100, the particular length of the PDE sensor
implemented on the rake's shaft 210 may preferably be selected to
measure the force and deflection on a part of the rake 200 deemed
most likely to fatigue. In this configuration, the PDE force sensor
214 may detect an angle of twist greater than 2 degrees along the
rotatable shaft 210 indicative of potentially excess motor torque
or an impacted ice cube.
[0029] As shown in FIG. 7, PDE force sensors 216 may be placed on
one or more of the fingers 212 of the rake 200. Consequently, the
removal force applied to expel each ice cube from a cavity 116 in
the ice cube mold 100 may be independently monitored. In this way,
one of the PDE force sensors 216 may detect excessive torsion of a
particular finger 212 indicative of an ice cube stuck in a cavity
116. By determining the particular cavity 116 where excessive force
may be required to expel an ice cube, additional actions may be
taken. Mitigating actions may include alerting the user or
automatically initiating a cleaning procedure.
[0030] FIG. 8 shows a side view of a portion of a refrigerator with
a door 20 having a ledge 308 on which the ice storage bin 22 may
rest and a freezer compartment 12 in which is mounted an ice maker
16. As described above, the ice maker 16 may be a twist ice maker
or a rotating rake ice maker. The ice maker 16 may further include
an output 314 for expelling ice cubes that is located above the ice
storage bin 22. As shown in FIG. 8, the output 314 for expelling
ice cubes from the ice maker 16 may be located above and may not
overlie the storage bin 22. The storage bin 22 defines an ice cube
reservoir 316 that has an opening 318 in communication with the ice
maker output 314 for receiving the ice cubes. Preferably, the
opening 318 is located at the top of the storage bin 22.
[0031] The base 320 of the ice storage bin 22 may be removably
supported on an ice storage bin mounting plate 322. When attached
to the ice storage bin mounting plate 322, the ice storage bin 22
is securely connected to the refrigerator 10. As best seen in FIG.
9, mating of protrusions 324 located on the ice storage bin
mounting plate 322 with recesses 326 in the base 320 of the ice
storage bin 22 may secure the removable connection. The protrusions
324 and corresponding recesses 326 may be provided anywhere along
the ice bucket mounting plate 322.
[0032] Provided on top of the protrusions 324 and, consequently,
below the ice storage bin 22, one or more PDE force sensors 310 may
detect the weight of the storage bin 22 including its content when
it is placed on the ice storage bin mounting plate 322. The PDE
force sensor 310 may experience a level of compression that
correlates with the weight placed on it. In this way, the PDE force
sensors 310 may output a signal that may be calibrated to indicate
the weight of the ice cubes within the ice cube reservoir 316.
[0033] Typically, an ice storage bin 22 in a freezer compartment of
a refrigerator 10 is designed to maximize the ice cube reservoir
316. That is, the storage bin 22 may assume the maximum dimensions
of the space available in the freezer compartment and the ice
harvesting process may be configured to produce ice until the ice
cube reservoir 316 completely fills the storage bin 22.
Consequently, for many consumers, the storage bin 22 may hold an
undesirable amount of ice that may become stagnant and malodorous
or may sublimate from unuse. To avoid the problem of ice staleness,
it may be desirable to limit the amount of ice available based on
an individual consumer's preference.
[0034] Therefore, to detect the level of ice storage, the
controller 104 in communication with the PDE force sensor 310 may
monitor the ice level by determining the weight of the ice storage
bin 22 with ice cubes in the ice cube reservoir 316. In response to
the determined level of ice based on the PDE force sensor output
and a user-defined input stating a desired level of ice, the
controller may prevent additional ice harvesting by the ice maker
16. The controller 104 may allow for continued ice harvesting once
the level of ice storage falls below the consumer's desired level.
For example, upon consumption of ice cubes, the PDE force sensor
310 may continue to output a signal to indicate the weight of the
ice cubes. Once the weight falls below the value associated with
the desired level of ice storage, the controller may signal the ice
maker 16 to continue harvesting. Alternatively, the consumer may
choose to increase the desired level of ice storage.
[0035] In addition to preventing an ice harvesting process when the
ice reservoir 316 reaches a desired level of ice cubes, the ice
making assembly may be designed to prevent ice harvesting when the
storage bin 22 is removed from the refrigerator 10. As shown in
FIG. 8, the PDE sensor 310 may detect when the storage bin 22 is
not positioned 328 to receive ice cubes. Upon detection of a
voltage indicative of little or no weight being applied, the PDE
sensor 310 may transmit a signal to the controller 104. The
controller 104 may then prevent the ice maker 16 from expelling ice
cubes to the storage bin 22.
[0036] Depending upon the placement and configuration of the PDE
sensor 310 and controller 104, it is contemplated that the PDE
sensor 310 may be operated in a wireless configuration. While it is
generally known to operate sensors with either a hard-wired or
wireless connection, typical wireless sensors require external
power sources that require additional wiring to power supplies. As
previously described, PDE sensors 310 require very little power for
operations. Additionally, PDE devices may be configured to generate
power when exposed to mechanical vibrations. That is, PDE devices
may scavenge energy from ambient vibrations. For refrigerators,
sources of mechanical vibration may include a power cycle of the
compressor, placement of the ice storage bin 22 onto the ice
storage bin mounting bracket 322, the kinetic energy from harvested
ice landing in the ice storage bin 22, the weight of products as
they are placed on refrigerator shelves, etc. By either storing
scavenged energy into a battery or using power on demand, the PDE
sensor 310 may locally source power for operating a wireless
connection to the controller 104. The PDE force sensor 310 and the
energy scavenging PDE device may be the same device or may be
implemented as separate devices. While operating one or more PDE
sensors with a power scavenging PDE device may provide a desirable
power saving feature, it is noted that a more typical wired
connection to enable communication between the PDE sensor 310 and
the controller 104 may be implemented.
[0037] While the invention has been specifically described in
connection with certain specific embodiments thereof, it is to be
understood that this is by way of illustration and not of
limitation. Reasonable variation and modification are possible
within the scope of the forgoing disclosure and drawings without
departing from the spirit of the invention which is defined in the
appended claims.
* * * * *