Recoverable domestic ice maker

• US 5,160,094 A
• Filed: 02/24/1992
• Issued: 11/03/1992
• Est. Priority Date: 02/24/1992
• Status: Expired due to Term

• Current Assignee: Whirlpool Corporation
• Original Assignee: Whirlpool Corporation
• Inventors: Giordano, James R., Willis, James L.
• Primary Examiner(s): Tapolcai, William E.
• Application Number:
  US07/840,027
• Time in Patent Office: 253 Days
• Field of Search: 62/73, 62/135, 62/137, 62/351, 62/353, 62/344
• US Class Current: 62/137
• CPC Class Codes: F25C 1/04 by using stationary moulds
• CPC Class Codes: F25C 2305/024 Rotating rake
• CPC Class Codes: F25C 5/08 by heating bodies in contact with the ice

Abstract

An ice making apparatus includes a mold in which water is frozen to form an ice body. Also included are an electric motor and an ejector blade for ejecting the ice body from the mold. An electric heater in heat transfer association with the mold is operable to free the ice bodies from the mold prior to the ejector blade ejecting the ice bodies. A control circuit includes a thermostat responsive to temperature of water in the mold. A thermostat switch is controlled by the thermostat to initiate operation of the motor for ejecting the ice body upon complete freezing thereof and concurrently energizing the heater. An electric circuit includes the thermostat switch, the motor and a second switch controlled by the operation of the motor for maintaining energization of the motor independently of the first switch and causing the thermostat switch to control further energization of the heater whereby the thermostat switch de-energizes the heater within a single revolution of the ejector blade. The motor also drives a cam and cam follower for controlling a sensing arm for sensing a full ice condition. The ice maker includes structure for suspending operation of the ice maker in the event that the sensing arm is obstructed.

Claims

1. An ice making apparatus comprising:

a mold in which water is frozen to form an ice body;

means for ejecting the ice body from the mold;

an electric motor;

a drive system driven by said motor and operatively driving said ejecting means;

an electric heater in heat transfer association with the mold for freeing the ice body from the mold;

control circuit means including a thermostat, said thermostat being responsive to temperature of the mold, a thermostat switch controlled by said thermostat to initiate a harvest cycle by energizing said motor for ejecting the ice body upon complete freezing thereof and concurrently energizing said heater, and electric circuit means including said thermostat switch, said motor, said heater and a holding switch controlled by operation of said motor for maintaining energization of said motor independently of said thermostat switch and causing the thermostat switch to control further energization of the heater;

a sensor arm for sensing a quantity of ice bodies previously ejected by the ice making apparatus and stored therebelow; and

a linkage mechanism driven by said drive system for controllably positioning said sensing arm in a raised or lowered position, said sensing arm normally being in the lowered position and said linkage mechanism controllably raising said sensing arm and subsequently lowering said sensing arm at select operational positions of said drive system during a harvest cycle of operation to determine if a preselected quantity of ice bodies is stored therebelow, said linkage system coacting with said drive system to operate in a failsafe mode during a harvest cycle to prevent further operation of said motor in response to an obstruction preventing the raising of said sensing arm, and immediately continuing said harvest cycle upon removal of said obstruction.

2. The ice making apparatus of claim 1 wherein said motor comprises a low torque impedance protected motor, whereby said motor easily stalls in response to an obstruction preventing raising of said sensing arm.

3. The ice making apparatus of claim 1 wherein said drive system includes a cam surface and said linkage mechanism comprises a pivotal lever arm having a cam follower driven by said cam surface for controllably positioning said sensing arm.

4. The ice making apparatus of claim 3 wherein said cam follower comprises a radial surface coacting with said cam surface.

5. The ice making apparatus of claim 3 wherein said lever arm comprises a planar surface partially surrounded by a perpendicular perimeter reinforcement wall.

6. The ice making apparatus of claim 1 wherein said drive system is configured so that ice bodies are completely freed from the mold prior to driving said linkage mechanism to raise said sensing arm.

7. In an ice making apparatus including a mold in which water is frozen to form an ice body, a thermostat, said thermostat being responsive to temperature of the mold, means for ejecting the ice body from the mold, an electric motor, a drive system driven by said motor and operatively driving said ejecting means, an electric heater in heat transfer association with the mold for freeing the ice body from the mold, a sensor arm movable between a raised shutoff position and a lowered sensing position for sensing a quantity of ice bodies previously ejected by the ice making apparatus and stored therebelow, and a linkage mechanism driven by said drive system for controllably positioning said sensing arm in a raised or lowered position, the improvement comprising:

control means for operating said ice making apparatus in one of four control modes, a first mode comprising a shutoff mode for disabling operation of the ice making apparatus in response to said sensor arm being in the raised position, a second mode comprising a freezing mode for freezing water contained in said mold, a third mode comprising a harvest mode initiated response to said thermostat sensing that water in said mold is frozen as by energizing said heater and concurrently energizing said motor for ejecting the ice body, said sensing arm normally being in the lowered position and said linkage mechanism controllably raising said sensing arm and subsequently lowering said sensing arm at select operational positions of said drive system during the harvest mode of operation to determine if a preselected quantity of ice bodies is stored therebelow, and a fourth mode comprising a failsafe mode to prevent further operation of said motor in response to an obstruction preventing the raising or lowering of said sensing arm, and immediately returning to said harvest mode upon removal of said obstruction.

8. The ice making apparatus of claim 7 wherein said improvement further comprises said motor being a low torque impedance protected motor, whereby said motor easily stalls in response to an obstruction preventing raising of said sensing arm.

9. The ice making apparatus of claim 7 wherein said improvement further comprises said drive system including a cam surface and said linkage mechanism comprising a pivotal lever arm having a cam follower driven by said cam surface for controllably positioning said sensing arm.

10. The ice making apparatus of claim 9 wherein said cam follower comprises a radial surface coacting with said cam surface.

11. The ice making apparatus of claim 9 wherein said lever arm comprises a planar surface partially surrounded by a perpendicular perimeter reinforcement wall.

12. The ice making apparatus of claim 7 wherein said improvement further comprises said drive system being configured so that ice bodies are completely freed from the mold prior to driving said linkage mechanism to raise said sensing arm.