Title:
COOLER WITH MULTI-PARAMETER CUBE ICE MAKER CONTROL
Kind Code:
A1


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, US)
Application Number:
11/682035
Publication Date:
04/24/2008
Filing Date:
03/05/2007
Primary Class:
International Classes:
F25C1/04
View Patent Images:



Primary Examiner:
DUKE, EMMANUEL E
Attorney, Agent or Firm:
QUARLES & BRADY LLP (MILWAUKEE, WI, US)
Claims:
We claim:

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

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

Not applicable.

BACKGROUND OF THE INVENTION

1. Technical Field

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.

2. Description of the Related Art

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.

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.

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.

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

The present invention addresses the aforementioned problems and provides an improved multi-parameter cube ice maker control.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

The cooling unit can include a user input and the predetermined time period or the threshold temperature can be set by the user input.

The water valve switch can be thrown by the cam during the second portion thereby causing the cavities to fill with water.

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.

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.

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.

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.

The start line period of time can be thirty seconds and the complete ejection period of time can be ten minutes.

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

FIG. 1 is a perspective view of a combination refrigerator/freezer unit having the features of the present invention;

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;

FIG. 3 is a front elevation view thereof with the cabinet door removed;

FIG. 4 is an exploded assembly view thereof;

FIG. 5 is a perspective view of a cube ice maker assembly of the combination unit;

FIG. 6 is an exploded perspective view of the ice maker assembly;

FIG. 7 is an exploded perspective view of the ice maker assembly;

FIG. 8 is a diagram of the refrigeration system of the combination unit;

FIG. 9 is a schematic of the electrical system of the combination unit of FIG. 1;

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;

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;

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;

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

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

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.