COOLER WITH MULTI-PARAMETER CUBE ICE MAKER CONTROL
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.
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 DEVELOPMENTNot applicable.
BACKGROUND OF THE INVENTION1. 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 INVENTIONThe 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.
Referring to
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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
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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
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
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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
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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.
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.
Type: Application
Filed: Mar 5, 2007
Publication Date: Apr 24, 2008
Inventor: Andrew J. Doberstein (Hartford, WI)
Application Number: 11/682,035
International Classification: F25C 1/04 (20060101);