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Cooler with multi-parameter cube ice maker control

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.

Not applicable.

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.

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.