U.S. patent application number 11/682035 was filed with the patent office on 2008-04-24 for cooler with multi-parameter cube ice maker control.
Invention is credited to Andrew J. Doberstein.
Application Number | 20080092574 11/682035 |
Document ID | / |
Family ID | 39316604 |
Filed Date | 2008-04-24 |
United States Patent
Application |
20080092574 |
Kind Code |
A1 |
Doberstein; Andrew J. |
April 24, 2008 |
COOLER WITH MULTI-PARAMETER CUBE ICE MAKER CONTROL
Abstract
A cooling unit with a refrigeration assembly including an
evaporator and an insulated cabinet including an ice maker chamber
that is cooled by the evaporator. The cooling unit includes an ice
maker mechanism disposed in the ice maker chamber, the ice maker
mechanism including an ice mold with cavities, an ice mold heater,
ejector blades, and strippers. The ice maker mechanism can produce
ice and eject the ice into an ice bin within the cabinet during a
plurality of ice ejection cycles. The ice is ejected by energizing
the mold heater and rotating the plurality of ejector blades
through the plurality of cavities. A controller tracks an elapsed
time since a previous ice ejection cycle and prohibits a next ice
ejection cycle when the elapsed time is below a prescribed time
period. A next ice ejection cycle is also prohibited when an ice
mold thermistor is below a threshold temperature.
Inventors: |
Doberstein; Andrew J.;
(Hartford, WI) |
Correspondence
Address: |
QUARLES & BRADY LLP
411 E. WISCONSIN AVENUE, SUITE 2040
MILWAUKEE
WI
53202-4497
US
|
Family ID: |
39316604 |
Appl. No.: |
11/682035 |
Filed: |
March 5, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60862376 |
Oct 20, 2006 |
|
|
|
Current U.S.
Class: |
62/233 |
Current CPC
Class: |
F25D 2400/40 20130101;
F25D 2600/02 20130101; F25C 5/187 20130101; F25C 2600/04 20130101;
F25C 1/04 20130101; F25C 2700/12 20130101 |
Class at
Publication: |
62/233 |
International
Class: |
F25C 1/04 20060101
F25C001/04 |
Claims
1. A cooling unit, comprising: a refrigeration assembly including
an evaporator; an insulated cabinet including an ice maker chamber
that is cooled by the evaporator; an ice maker mechanism disposed
in the ice maker chamber, the ice maker mechanism including an ice
mold forming a plurality of cavities, an ice mold heater in thermal
conductivity with the ice mold, a motor, a plurality of ejector
blades configured to be driven by the motor to eject ice from the
plurality of cavities, and a plurality of strippers attached to the
ice mold to aid in the ejection of ice, the ice maker mechanism
being capable of producing ice and ejecting the ice into an ice bin
within the insulated cabinet during a plurality of ice ejection
cycles by energizing the mold heater and rotating the plurality of
ejector blades through the plurality of cavities; and a controller
configured to track an elapsed time since a previous ice ejection
cycle and prohibit a next ice ejection cycle when the elapsed time
is below a prescribed time period.
2. The cooling unit of claim 1, further comprising a thermistor
positioned in thermal contact with the ice mold, the thermistor
sensing a mold temperature, wherein the controller monitors the
mold temperature and prevents the next ice ejection cycle when the
mold temperature is above a threshold temperature.
3. The cooling unit of claim 2, wherein ice maker mechanism is
configured to fill the ice mold with water during each of the
plurality of ice ejection cycles after the ice has been
ejected.
4. The cooling unit of claim 2, wherein the controller is
configured to provide power to the ice making assembly only if
first and second conditions are met, wherein in the first condition
the mold temperature is essentially below the threshold temperature
and in the second condition the elapsed time period is greater than
the prescribed time period.
5. The cooling unit of claim 4, further comprising a start ejection
cycle line and a complete ejection cycle line, wherein the
controller is configured to provide power to the start ejection
cycle line for a start line period and the complete ejection cycle
line for a complete line period.
6. The cooling unit of claim 5, wherein the ice maker assembly is
configured so that only the start ejection cycle line provides
energy to the motor and heater during a first portion of one
ejection cycle and only the complete ejection cycle line provides
energy to the motor and heater during a second portion of one
ejection cycle.
7. The cooling unit of claim 6, wherein the ice maker assembly
includes a cam configured to rotate when the ejector blades rotate,
a bin switch positioned adjacent the cam, a hold switch positioned
adjacent the cam, and a water valve switch positioned adjacent the
cam, wherein the cam includes indents configured to throw the hold
switch and the water valve switch.
8. The cooling unit of claim 7, wherein the hold switch is a double
pole single throw switch.
9. A cooling unit, comprising: a refrigeration assembly including
an evaporator; an insulated cabinet including an ice maker chamber
that is cooled by the evaporator; an ice maker mechanism disposed
in the ice maker chamber, the ice maker mechanism including an ice
mold forming a plurality of cavities, an ice mold heater in thermal
conductivity with the ice mold, a motor, an ejector blade shaft
configured to be driven by the motor, a plurality of ejector blades
extending from the ejector blade shaft, a plurality of strippers
attached to the ice mold, a cam configured to be driven by the
motor, a hold switch positioned adjacent the cam, a water valve
switch positioned adjacent the cam, an ice level arm configured to
sense a level of ice in the ice bin, and an ice bin switch
configured to be thrown by the ice level arm, the ice maker
mechanism being capable of producing ice and ejecting the ice into
an ice bin within the insulated cabinet during a plurality of ice
ejection cycles by energizing the mold heater and rotating the
plurality of ejector blades through the plurality of cavities; a
start ejection cycle line connected to the ice bin switch; a
complete ejection cycle line connected to the hold switch; an ice
mold thermistor positioned in thermal contact with the ice mold,
the ice mold thermistor sensing a mold temperature; and a
controller configured to track an elapsed time since a previous ice
making cycle, monitor the ice bin temperature and provide power to
the start ejection cycle line and the complete ejection cycle line
when the elapsed time since a previous ice ejection cycle is
greater than a predetermined time period and the ice mold
temperature is above a threshold temperature.
10. The cooling unit of claim 9, wherein the controller provides
power to the start ejection cycle line for a start line period of
time and to the complete ejection cycle line for a complete line
period of time; wherein the start line period of time is less than
the complete line period of time.
11. The cooling unit of claim 10, wherein the ice making cycles
each include a first portion and a second portion, the motor
receiving power from the start ejection cycle line during the first
portion and from the complete ejection cycle line during the second
portion.
12. The cooling unit of claim 11, wherein the ice is ejected during
the second portion.
13. The cooling unit of claim 12, wherein the hold switch is thrown
by the cam to switch between the first portion and the second
portion.
14. The cooling unit of claim 10, further comprising a user input,
wherein one of the predetermined time period and the threshold
temperature can be set by the user input.
15. The cooling unit of claim 10, wherein the water valve switch is
thrown by the cam during the second portion thereby causing the
cavities to fill with water.
16. A method for controlling a cooling unit with a refrigeration
assembly including an evaporator, an insulated cabinet including an
ice maker chamber that is cooled by the evaporator, and an ice
maker mechanism disposed in the ice maker chamber, the ice maker
mechanism including an ice mold forming a plurality of cavities, an
ice mold heater in thermal conductivity with the ice mold, a motor,
a plurality of ejector blades configured to be driven by the motor,
and a plurality of strippers connected to the ice mold and
configured to aid in the ejection of ice, the ice maker mechanism
being capable of producing ice and ejecting the ice into an ice bin
within the insulated cabinet during a plurality of ice ejection
cycles by energizing the mold heater and rotating the plurality of
ejector blades through the plurality of cavities, the method
comprising: tracking an elapsed time since a previous ice ejection
cycle; and prohibiting a next ice ejection cycle when the elapsed
time is below a prescribed time period.
17. The method of claim 16, further comprising sensing an ice mold
temperature of the ice mold and prohibiting the next ice ejection
cycle when the ice mold temperature is above a threshold
temperature.
18. The method of claim 17, further comprising starting the next
ice ejection cycle by providing power concurrently on a start
ejection cycle line and on a complete ejection cycle line.
19. The method of claim 18, wherein power is provided on the start
ejection cycle line for a start line period of time and on the
complete ejection cycle line for a complete ejection period of
time.
20. The method of claim 18, wherein the start line period of time
is thirty seconds and the complete ejection period of time is ten
minutes.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
patent application Ser. No. 60/862,376 filed on Oct. 20, 2006, and
entitled "Cooling Unit," hereby incorporated by reference as if
fully set forth herein.
STATEMENT OF FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
BACKGROUND OF THE INVENTION
[0003] 1. Technical Field
[0004] The present invention relates to refrigerated food and drink
storage units that include ice making assemblies, and in
particular, to a multi-parameter control therefore.
[0005] 2. Description of the Related Art
[0006] Refrigerators and coolers for the cold storage of food and
beverages are well known and can come in full-size standup units or
compact, under-cabinet units. Ice maker assemblies can be disposed
in the freezer sections of refrigerators in order to produce ice
and eject the ice into ice bins that are also disposed in the
freezer sections.
[0007] The ice maker assemblies rely on the temperature of the
freezer section to freeze the water into ice. It is common that
water is deposited in a metal ice cube tray with multiple cavities.
The water is cooled by the air in the freezer section and frozen
into ice cubes. Multiple ejectors complete a full three-hundred and
sixty degree rotation to forcibly eject the ice cubes from the tray
cavities after the ice has frozen. A mold heater is used to heat
the tray and partially melt the ice to aid the ejection of ice.
[0008] After the ice is ejected from the cavities of the ice tray,
a water valve is opened to deposit water in the cavities. The
cavities are filled with water every time the ejectors are rotated
a full three-hundred and sixty degrees.
[0009] Typically, the ejection of the ice is initiated when a
thermostat mechanically closes a circuit that causes a motor to
rotate the ejectors. The ice maker assembly circuit is constantly
provided with power so that if the thermostat malfunctions, the
motor can be driven and the ejector blades driven through an
ejection cycle, which includes the deposit of water into the tray
cavities. This can be problematic when the water in the cavities
has not yet frozen or has only partially frozen. Partially formed
ice cubes can thereby be ejected in to the ice bin. The cavities
may be overfilled with water that freezes into a large ice block
that can not be removed by the ejector blades. Water may also fall
into the ice bin, the water causing the ice stored in the ice bin
to freeze together into a solid block. Frozen blocks of ice in the
ice bin can make it difficult for a user to get ice from the ice
bin and can prevent an automatic ice dispenser from operating
correctly. A series ejection cycles when the water is not frozen
can result in flooding the cooling unit thereby destroying food
product. In the worst case, the water escapes the cooling unit and
causes damage outside of the cooling unit.
SUMMARY OF THE INVENTION
[0010] The present invention addresses the aforementioned problems
and provides an improved multi-parameter cube ice maker
control.
[0011] One aspect of the present invention provides a cooling unit
with a refrigeration assembly including an evaporator, an insulated
cabinet including an ice maker chamber that is cooled by the
evaporator, and an ice maker mechanism disposed in the ice maker
chamber. The ice maker mechanism includes an ice mold forming a
plurality of cavities, an ice mold heater in thermal conductivity
with the ice mold, a motor, a plurality of ejector blades
configured to be driven by the motor to eject ice from the
plurality of cavities, and a plurality of strippers attached to the
ice mold to aid in the ejection of ice. The ice maker mechanism is
capable of producing ice and ejecting the ice into an ice bin
within the insulated cabinet during a plurality of ice ejection
cycles by energizing the mold heater and rotating the plurality of
ejector blades through the plurality of cavities. A controller is
configured to track an elapsed time since a previous ice ejection
cycle and prohibit a next ice ejection cycle when the elapsed time
is below a prescribed time period.
[0012] A thermistor can be positioned in thermal contact with the
ice mold to sense an ice mold temperature. The controller can
monitor the mold temperature and prevent the next ice ejection
cycle when the mold temperature is above a threshold
temperature.
[0013] The ice maker mechanism can be configured to fill the ice
mold with water during each of the plurality of ice ejection cycles
after the ice has been ejected.
[0014] The controller can be configured to provide power to the ice
making assembly only if first and second conditions are met. The
first condition is that the mold temperature is essentially below
the threshold temperature and the second condition is that the
elapsed time period is greater than the prescribed time period.
[0015] The cooling unit can include a start ejection cycle line and
a complete ejection cycle line. The controller can be configured to
provide power to the start ejection cycle line for a start line
period and the complete ejection cycle line for a complete line
period.
[0016] The ice maker assembly can be configured so that only the
start ejection cycle line provides energy to the motor and heater
during a first portion of one ejection cycle and only the complete
ejection cycle line provides energy to the motor and heater during
a second portion of one ejection cycle.
[0017] The ice maker assembly includes a cam configured to rotate
when the ejector blades rotate, a bin switch positioned adjacent
the cam, a hold switch positioned adjacent the cam, and a water
valve switch positioned adjacent the cam. The cam can include
indents configured to throw the hold switch and the water valve
switch. The hold switch can be a double pole single throw
switch.
[0018] Another aspect of the invention provides a cooling unit with
a refrigeration assembly including an evaporator, an insulated
cabinet including an ice maker chamber that is cooled by the
evaporator, an ice maker mechanism disposed in the ice maker
chamber. The ice maker mechanism can include an ice mold forming a
plurality of cavities, an ice mold heater in thermal conductivity
with the ice mold, a motor, an ejector blade shaft configured to be
driven by the motor, a plurality of ejector blades extending from
the ejector blade shaft, a plurality of strippers attached to the
ice mold, a cam configured to be driven by the motor, a hold switch
positioned adjacent the cam, a water valve switch positioned
adjacent the cam, an ice level arm configured to sense a level of
ice in the ice bin, an ice bin switch configured to be thrown by
the ice level arm. The ice maker mechanism can produce ice and
eject the ice into an ice bin within the insulated cabinet during a
plurality of ice ejection cycles by energizing the mold heater and
rotating the plurality of ejector blades through the plurality of
cavities. The cooling unit can also include a start ejection cycle
line connected to the ice bin switch, a complete ejection cycle
line connected to the hold switch, an ice mold thermistor
positioned in thermal contact with the ice mold. The ice mold
thermistor can sense a mold temperature. A controller can be
configured to track an elapsed time since a previous ice making
cycle, monitor the ice bin temperature and provide power to the
start ejection cycle line and the complete ejection cycle line when
the elapsed time since a previous ice ejection cycle is greater
than a predetermined time period and the ice mold temperature is
above a threshold temperature.
[0019] The controller can provide power to the start ejection cycle
line for a start line period of time and to the complete ejection
cycle line for a complete line period of time. The start line
period of time can be less than the complete line period of
time.
[0020] The ice making cycles can each include a first portion and a
second portion. The motor can receive power from the start ejection
cycle line during the first portion and from the complete ejection
cycle line during the second portion. The ice can be ejected during
the second portion. The hold switch can be thrown by the cam to
switch between the first portion and the second portion.
[0021] The cooling unit can include a user input and the
predetermined time period or the threshold temperature can be set
by the user input.
[0022] The water valve switch can be thrown by the cam during the
second portion thereby causing the cavities to fill with water.
[0023] Another aspect of the invention provides a method for
controlling a cooling unit with a refrigeration assembly including
an evaporator, an insulated cabinet including an ice maker chamber
that is cooled by the evaporator, and an ice maker mechanism
disposed in the ice maker chamber, the ice maker mechanism
including an ice mold forming a plurality of cavities, an ice mold
heater in thermal conductivity with the ice mod, a motor, a
plurality of ejector blades configured to be driven by the motor,
and a plurality of strippers connected to the ice mold and
configured to aid in the ejection of ice. The ice maker mechanism
can be capable of producing ice and ejecting the ice into an ice
bin within the insulated cabinet during a plurality of ice ejection
cycles by energizing the mold heater and rotating the plurality of
ejector blades through the plurality of cavities. The method can
include tracking an elapsed time since a previous ice ejection
cycle and prohibiting a next ice ejection cycle when the elapsed
time is below a prescribed time period.
[0024] The method can include sensing an ice mold temperature of
the ice mold and prohibiting the next ice ejection cycle when the
ice mold temperature is above a threshold temperature.
[0025] The method can include starting the next ice ejection cycle
by providing power concurrently on a start ejection cycle line and
on a complete ejection cycle line.
[0026] Power can be provided on the start ejection cycle line for a
start line period of time and on the complete ejection cycle line
for a complete ejection period of time.
[0027] The start line period of time can be thirty seconds and the
complete ejection period of time can be ten minutes.
[0028] Various other features and advantages of the present
invention will be made apparent from the following detailed
description and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 is a perspective view of a combination
refrigerator/freezer unit having the features of the present
invention;
[0030] FIG. 2 is a perspective view thereof similar to FIG. 1
albeit with its cabinet door open so that the interior of the
cabinet is visible;
[0031] FIG. 3 is a front elevation view thereof with the cabinet
door removed;
[0032] FIG. 4 is an exploded assembly view thereof;
[0033] FIG. 5 is a perspective view of a cube ice maker assembly of
the combination unit;
[0034] FIG. 6 is an exploded perspective view of the ice maker
assembly;
[0035] FIG. 7 is an exploded perspective view of the ice maker
assembly;
[0036] FIG. 8 is a diagram of the refrigeration system of the
combination unit;
[0037] FIG. 9 is a schematic of the electrical system of the
combination unit of FIG. 1;
[0038] FIG. 10 is the schematic of FIG. 9 showing only the lines of
the ice maker assembly that are energized during the first thirty
seconds of an ejection cycle;
[0039] FIG. 11 is the schematic of FIG. 9 showing only the lines of
the ice maker assembly that are energized after the first thirty
seconds of the ejection cycle when the hold switch is thrown;
[0040] FIG. 12 is the schematic of FIG. 9 showing only the lines of
the ice maker assembly that are energized after the first thirty
seconds of the ejection cycle when the hold switch is not
thrown;
[0041] FIG. 13 is the schematic of FIG. 9 showing only the lines of
the ice maker assembly that are energized during a water fill of an
ejection cycle; and
[0042] FIG. 14 is the schematic of FIG. 9 showing only the lines of
the refrigeration system that are energized during a refrigeration
cycle.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0043] Referring to FIGS. 1-4, in one preferred form, a combination
refrigerator/freezer unit 30 includes a cabinet 32 defining a
cavity with a forward opening 34 that is divided by horizontal and
vertical partition walls 36 and 38, respectively, into a
refrigerator section 40 and an ice section 42. The refrigerator
section 40 is an L-shaped chamber having a molded insert liner 44
with grooves that support shelves 46 (two are shown in the
drawings). The shelves 46 are supported by corresponding grooves
formed in the vertical partition wall 38. Molded insert liner 44
includes a pair of grooves that support a lower support shelf 48
and defines a recess for a crisper drawer 50. The ice section 42 is
a rectangular chamber having a foam insulated, molded insert 52
containing a cube ice maker assembly 56 and an ice storage bin 58.
The ice section 42 is closed by a door 60 that is hinged to insert
52 along one vertical side thereof. The cabinet opening 34 is
closed by a door 64 that is hinged to the cabinet 32 (with
self-closing cams) along one vertical side thereof. Both the
cabinet 32 and the door 64 are formed of inner molded plastic
members and outer formed metal members with the space filled in
with an insulating layer of foam material, all of which is well
known in the art. The door 64 has a handle 65 and can include one
or more door shelves.
[0044] Referring now to FIGS. 4 and 8, along the back wall of the
ice section 42 is an evaporator 62 with serpentine refrigerant
tubes running through thin metal fins, which is part of a
refrigeration system 65 of the unit 30. The evaporator 62 has an
outlet line 66 which is connected to the inlet of a compressor 70.
A discharge line 72 connected to the outlet of the compressor 70 is
connected to the inlet of a condenser 74 having an outlet line 76
connected to a dryer 78. A capillary tube 80 leads from the dryer
78 to an inlet line 82 of the evaporator 62. A bypass line 84 leads
from the dryer 78 to the inlet line 82 of the evaporator. A hot gas
bypass valve 86 controls communication between the dryer 78 and the
evaporator 62. Bypass valve 86 can be an electronically controlled
solenoid type valve. An evaporator fan 89 is positioned near the
evaporator 62 and a condenser fan 90 (see FIG. 9) is positioned
near the condenser 74. An evaporator pan 92 is positioned beneath
the evaporator 62 and is configured to collect and drain water. An
evaporator pan heater 94 is beneath the evaporator pan 92 to heat
the evaporator pan 92. The compressor 70, condenser 74 and
condenser fan (see FIG. 13) are located at the bottom of the
cabinet 32 below the insulated portion.
[0045] Referring now to FIGS. 4-7, the cube ice maker assembly 56
is positioned in the upper part of the ice section 42 of the
cabinet 32. The ice storage bin 58 is positioned in the lower part
of the ice section 42 of the cabinet 32. The cube ice maker
assembly 56 includes a housing 100, water inlet (not shown), drive
assembly 104 and cube ice mold 106, which is also known as an ice
tray. The water inlet is connected to an electronic water valve 103
(see FIGS. 9 and 13) that controls the flow of water into the cube
ice maker assembly 56. The water inlet is connected to a water
transport mechanism (not shown) of the ice maker assembly 56 that
transports water to the cavities of the cube ice mold 106 in order
to fill the cube ice mold 106 with water when the electronic water
valve 103 (see FIG. 13) is opened. The drive assembly 104 comprises
a cover 108 that surrounds an electric motor 110. A plurality of
ejector blades 112 are configured to be rotated by the electric
motor 110 in order to engage ice formed in the cube ice mold 106
and carry the ice out of the cube ice mold 106, the ice stripped by
a plurality of strippers 114 formed on a stripper plate 116, the
ice dropping below into the ice storage bin 58. A mold heater 118
is in thermal communication with the cube ice mold 106 and is
configured to provide heat to the cube ice mold 106 to loosen the
ice from the cube ice mold 106 to aid the ejector blades 112 in
ejecting the ice. A pivotably mounted ice level sensing arm 120
extends downwardly above the ice storage bin 58 to sense the level
of the ice in the ice storage bin 58. Switches or sensors can be
used to detect the position of the ejector blades 112 and/or motor
110 as well as the state of the cube ice maker assembly 56 (e.g.,
water fill, freeze and harvest stages) as discussed below.
[0046] Referring now to FIGS. 4 and 13, a controller 128 is
attached below the cabinet and adjacent a kickplate 130 positioned
below the cabinet door 64. The controller 128 comprises a
microprocessor (not shown) that is connected to a memory (not
shown). Alternatively, the microprocessor can include a memory. A
plurality of connectors and lines (not shown) connect the
controller 128 to sensors (discussed below) and relays associated
with the other electrical components (not shown) of the
refrigeration unit 30. A refrigerator section temperature sensor
138 is attached to refrigerator section 40 (see FIGS. 3 and 4) and
senses the temperature of refrigerator section and provides
refrigerator section temperature information to the controller 128.
An ice section temperature sensor 140 is attached to the ice
section 42 (see FIGS. 3 and 4) and senses the temperature of the
ice section 42 and provides ice section temperature information to
the controller 128. A cube ice mold temperature sensor 144 (see
FIG. 5) is positioned within the cube ice mold 106 to measure the
temperature of the cube ice mold 106 at a position adjacent to a
cavity of the cube ice mold 106 where the ice is formed, the cube
ice mold temperature sensor 144 providing cube ice mold temperature
information to the controller 128. The temperature sensors 138,
140, and 144 can comprise thermistors or other appropriate
temperature sensors. The controller 128 is configured to control
refrigeration, ice making, defrost and other aspects of the
refrigeration unit 30 as will be described hereinafter. The
controller 128 is also configured to monitor data relating to the
operation of the refrigeration unit 30 and to log the data in the
controller memory 134 for access by a service technician as
discussed hereinafter. The logged data can include error codes.
[0047] As is known, the compressor 70 draws refrigerant from the
evaporator 62 and discharges the refrigerant under increased
pressure and temperature to the condenser 74. The hot,
pre-condensed refrigerant gas entering the condenser 74 is cooled
by air circulated by the condenser fan 90. As the temperature of
the refrigerant drops under substantially constant pressure, the
refrigerant in the condenser 74 liquefies. The smaller diameter
capillary tube 80 maintains the high pressure in the condenser 74
and at the compressor outlet while providing substantially reduced
pressure in the evaporator 62. The substantially reduced pressure
in the evaporator 62 results in a large temperature drop and
subsequent absorption of heat by the evaporator 62. The evaporator
fan 89 can draw air from inside the ice section 42 across the
evaporator 62, the cooled air returning to the ice section 42 to
cool the ice section 42. At least one air passage (not shown)
connects the ice section 42 and the refrigerator section 40 so that
the refrigerator section 40 is cooled by the ice section 42, the
temperature of the refrigerator section 40 related to the
temperature of the ice section 42. The compressor 70, condenser fan
90 and evaporator fan 89 are controlled by the controller 128 to
maintain the ice section 42 at an ice section setpoint. The ice
section setpoint is based on a refrigerator section setpoint (e.g.,
ice section set point is minus 30 degrees Fahrenheit of the
refrigerator section setpoint), the refrigerator section setpoint
being inputted by a user as described below. The controller 128
logs the compressor runtime between defrost cycles and stores the
compressor runtime in the controller memory 134.
[0048] As mentioned, the refrigeration system includes a hot gas
bypass valve 86 disposed in bypass line 84 between the dryer 78 and
the evaporator inlet line 82. Hot gas bypass valve 86 is controlled
by controller 128. The evaporator 62 is defrosted for a defrost
time up to a maximum defrost time after a certain amount of
compressor runtime. When the hot gas bypass valve 86 is opened, hot
pre-condensed refrigerant will enter the evaporator 62, thereby
heating the evaporator 62 and defrosting any ice buildup on the
evaporator 62. The evaporator pan heater 94 heats the evaporator
pan 92 when the hot gas bypass valve 86 is opened so that ice in
the evaporator pan 92 is melted at the same time that the
evaporator 62 is defrosted. The hot gas bypass valve 86 and
evaporator pan heater 94 are controlled by the controller 128
(i.e., the defrost cycle is controlled by the controller 128). The
controller 128 logs the defrost runtime and stores the defrost
runtime in the controller memory 134. The interval between defrost
cycles can be adjusted by the controller 128.
[0049] Referring now to FIGS. 5-7 and 9, the ice maker assembly 56
includes a small gear 160 that is driven by the motor 110, the
small gear 160 driving a large gear 162 that is connected to an
ejector shaft 164 including a cam 166. The ejector blades 112
extend from the ejector shaft 164. The motor 110 causes rotation of
the ejector shaft 164 and, thus, the ejector blades 112 and the cam
166. A bin switch 168 is positioned to be thrown by the ice level
sensing arm 120. The bin switch 168 is a double pole single throw
switch with a common contact 170, a normally closed contact 172 and
a normally closed contact 174. The ice level sensing arm 120 senses
the level of the ice in the ice bin 58 and the bin switch 168 is
configured to prevent an ice ejection cycle when the ice level
sensing arm 120 senses that the ice is above a maximum ice level. A
hold switch 176 is positioned to be thrown by the cam 166. The hold
switch 176 is a double pole single throw switch with a common
contact 178, a normally closed contact 180 and a normally open
contact 182. The cam 166 includes at least one indent (not shown)
that is configured to throw the hold switch 176 as the cam 166 is
rotated with the ejector blades 112 when the motor 110 is
energized. A water valve switch 184 is positioned to be thrown by
the cam 166. The water valve switch 184 is a double pole single
throw switch with a common contact 186, a normally closed contact
188, and a normally open contact 190. The cam 166 includes at least
one indent (not shown) that is configured to throw the water valve
switch 184. A normally closed bi-metal limit switch 192 (see FIG.
9) is disposed proximate the ice maker assembly 56 and is
configured to open in an overheating condition.
[0050] Referring now to FIG. 9, power is supplied to the ice maker
assembly 56 on a start ejection cycle line 194 (hereinafter the
"start line 194") and a complete ejection cycle line 196
(hereinafter the "complete line 196"). The lines 194 and 196 lines
are energized by a start ejection cycle relay and a complete
ejection cycle relay (not shown) that are controlled by the
controller 128 as discussed below. The start line 194 is connected
to the bin switch normally open contact 174. The bin switch
normally closed contact 172 is left open. The bin switch common
contact 170 is connected on a line 198 to the hold switch normally
closed contact 180. The hold switch common contact 178 is connected
on a line 200 to a line 206 to the motor 110, the mold heater 118
and the water valve switch common contact 186. The limit switch 192
is connected in serial in line 200. The motor 110 and mold heater
118 are connected in parallel between line 206 and a neutral line
208. The water valve switch normally closed contact 188 is
connected on a line 210 to the water valve 103. The water valve
switch normally open contact 190 is left open.
[0051] The controller 128 calls for an ejection cycle by providing
power on lines 194 as described below. The controller 128 decides
to call for an ejection cycle based on ice maker parameters
including the ice mold temperature and the time period since the
last ejection cycle. The controller 128 tracks the time period
since the last ejection cycle and monitors the ice mold temperature
provided by the ice mold thermistor 144. The controller determines
whether the time period since the last ejection cycle is greater
than a minimum time period between ejection cycles (e.g., twenty
minutes). If the time period since the last ejection cycle is
greater than the minimum time period between ejection cycles, the
controller 128 then determines whether the ice mold temperature is
below a threshold temperature (e.g., fifteen degrees Fahrenheit)
thereby indicating that the water has been frozen into ice cubes.
If the ice mold thermistor 144 is below the threshold temperature,
then the controller 128 calls for an ejection cycle. The time
period between ejection cycles must be greater than the minimum
time period between ejection cycles and the ice mold temperature
must be greater than the threshold temperature before the
controller 128 can call for an ejection cycle. Waiting the minimum
time period between ejection cycles, the ice ejection cycles can
avoid possible overfilling of the ice mold 106 and, thus, flooding
of the combination unit 30 and/or environment surrounding the
combination unit 30.
[0052] The controller 128 calls for an ejection cycle by energizing
the start line 194 for a start line time period and the complete
line 194 for a complete line time period. The start line time
period is shorter than the complete line time period.
[0053] The default state of the ice maker assembly 56 is a freeze
state. During the freeze state, the conditions required for an ice
ejection cycle call have not been met, which means that either the
ice mold temperature is above the threshold temperature or the time
period between ejection cycles is less than the minimum time period
between ejection cycles. Now referring to FIG. 14, in the freeze
state, the controller 128 can energize the refrigeration system,
but the controller 128 does not energize lines 194 and 196, which
means that the ejector blades 112 are immobile during the freeze
state. In the freeze state, the ejector blades 112 are in an
initial position and are positioned away from and perpendicular to
the ice mold 106 (as shown in FIG. 5). In the freeze state and when
the ice level sensing arm 120 has not activated the bin switch 168
(i.e., the ice level is not greater than the maximum ice level),
the bin switch 168 is in the activated position (i.e., the common
contact 170 and the normally open contact 172 are connected). In
the freeze state, the hold switch 176 is deactivated and the water
valve switch 184 is activated.
[0054] After the controller 128 has decided to call for an ejection
cycle, lines 194 and 196 are both energized beginning at the same
time. Start line 194 is energized for the start line period (e.g.,
thirty seconds) and the complete line 196 is energized for the
complete line period (e.g., ten minutes). Power can not be supplied
to the motor 110 and mold heater 118 when the limit switch 192 is
open. Hereinafter, it will be assumed that the limit switch 192 is
in the normally closed position. Now referring to FIG. 10, if the
ice level sensing arm 120 has deactivated the bin switch 168, power
is not supplied to the motor 110 and mold heater 118 because lines
194 and 196 are connected to contacts that are open. If the ice
level sensing arm 120 has not deactivated the bin switch 168,
energy is supplied to the motor 110 and mold heater 118 from start
line 194 through bin switch 168 to line 198 and from line 198
through hold switch 176 to line 200. Thereby the mold heater 118
heats the ice mold 106 and the motor 110 rotates the ejector blades
112 in a direction towards the strippers 114 (a counterclockwise
direction as shown in FIG. 5). The ejector blades 112 and, thus,
the cam 166 are rotated at least 90 degrees during the start line
period. When the cam 166 rotates 90 degrees, the cam 166 activates
the hold switch 176 thereby providing power to the motor 110 and
mold heater 118 from complete line 196 through hold switch 176 to
line 200 (as shown in FIG. 11). Power is no longer provided to the
motor 110 and mold heater 118 from the start line 194 even though
the start line 194 will remain energized until the start line
period has elapsed.
[0055] Referring now to FIG. 11, the motor 110 continues to rotate
in the same direction until the ejector blades 112 are returned to
the ejector blade initial position (as shown in FIG. 5) as long as
the complete line period did not elapse before the ejector blades
122 were able to return to the initial position (e.g., the blades
112 were prevented from rotating). During this rotation back to the
initial position, the ejector blades 112 cause the partially melted
ice to be ejected from the ice maker assembly 56 and thereafter the
cam 166 deactivates and reactivates the water valve switch 184
thereby opening and closing, respectively, the water valve 103 to
fill the ice mold 106 with a quantity of water. Alternatively, the
water valve switch 184 energizing the line 210 can comprise a water
fill signal to the water valve 103 and the water valve 103 can
itself meter the appropriate quantity of water to be used to fill
the ice mold 106. The cam 166 can be configured to cause the bin
level sensor arm 120 to be raised prior to ice ejection and lowered
after ice ejection, which does not interrupt the power supplied to
the motor 110 because the power is not run through bin switch 168
at this time. When the blades 112 return to the initial position,
the cam 166 is configured to deactivate the hold switch 178 thereby
interrupting the power supply to the motor 110 and the mold heater
118 so that the motor 110 stops rotating and the mold heater 118
stops heating, even though the complete line period has not elapsed
and complete line 196 is still energized (see FIG. 12). The motor
110 and mold heater 118 are not energized by start line 194 at this
time because start line 194 does not carry power at this time as
the controller 128 had previously turned off the power provided to
start line 194.
[0056] After the complete line period has elapsed, the controller
196 will turn off the power to the complete line 196 and the freeze
cycle will begin (see FIG. 14). During the freeze cycle, the motor
110 remains stationary and the mold heater 118 remains off until
the controller 128 calls for another ejection cycle by providing
power to start line 194 for the start line period and to the
complete line 196 for the complete line period as discussed
above.
[0057] Referring now to FIG. 7, a user control 210 is mounted to
the top of the refrigerator molded insert liner 44 within the
cabinet 32 for receiving user commands and forwarding input signals
to the main controller 128. The control unit 210 includes a display
panel 212 and a power input 214, a warmer input 216, a cooler input
218 and a light input 220. The mold temperature threshold, start
line time period and the complete line time period can inputted
through the user control 210 and thereby stored in the controller
128.
[0058] It should be appreciated that merely a preferred embodiment
of the invention has been described above. However, many
modifications and variations to the preferred embodiment will be
apparent to those skilled in the art, which will be within the
spirit and scope of the invention. Therefore, the invention should
not be limited to the described embodiment. To ascertain the full
scope of the invention, the following claims should be
referenced.
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