An ice maker control circuit for use with an ice maker of the type including an inclined refrigerated plate which is energized during a slab formation cycle during which water is continually circulated across the inclined refrigerated plate and wherein ice slabs released from the plate are directed to a cutting grid for melting the slab into a plurality of cubes of ice; the control circuit including a pair of ice thickness sensing thermostats each being associated with a transistorized control switch for selectively energizing first and second relay control switches in the water circulating pump circuit of the unit; the sensing thermostats being sequentially conditioned to terminate the recirculation of water across the slab under conditions wherein a slab release cycle fails to initiate because of the presence of a previously formed slab on the ice cutting grid.
An automatic ice making machine or apparatus of the type in which ice-making water is directed in jets upwards towards a freezing grid or chamber having a large number of freezing cells. The apparatus has an ice-cutting frame having second partitioning plates at a preset spacing from and in opposition to the lower ends of the first partitioning plates of said freezing cells, and a heating means provided to the cutting frame. The second partitioning plates are heated by a hot gas pipe for melting and cutting the ice formed in the freezing cells the end of the ice formation state and the end of harvesting state being detected by a temperature sensor provided on the ice cutting frame.
A refrigeration appliance is provided which has a freezer compartment, a fresh food compartment and a refrigeration system for cooling the two compartments. Two evaporators operating at different temperatures, or a single evaporator operating at sequentially different temperatures is used in the refrigeration system to provide the cooling of the two compartments. An ice making device is provided in the fresh food compartment, thermally associated with the evaporator used to cool the fresh food compartment operating at a warmer temperature, such that ice is formed and stored in the fresh food compartment. Dispensing means extending through the door of the fresh food compartment are provided to allow for dispensing of ice through the fresh food compartment door.
A vertical ice cube mold chilled by a refrigeration system has a water stream pumped into its open vertical face to build up ice cubes in the mold. A probe hangs over the open mold face at an adjustable spacing. When the mold fills with ice and the water stream contacts the probe, an electrical circuit is completed to cause a control to stop the water pump and heat the mold, thus harvesting the ice cubes. A timer restarts the icemaking cycle in case ice is not delivered for some reason. Casual water contact with the probe is prevented from tripping the control through the use of a simple integrator device.
The present invention provides an improved system and method for sensing of ice, particularly applicable in the control of ice thickness in automatic ice-making machines. The ice-making machine may be of the conventional type using a cold plate with water flowing over it. A thermistor bead temperature sensor is encapsulated in a metal housing, which is in turn mounted on a carrier. The position of the carrier is adjustable relative to the cold plate. The control system has several variable delays or time durations which optimize system performance: 1. Minimum harvest time delay, relative to the start of the ice-making cycle; 2. Threshold persistence time delay, requires that the signal sensor persists above the harvest threshold value for a certain amount of time (referenced to when the threshold is first exceeded), before harvesting may begin; 3. Harvesting delay is an optional delay provided give the option of making sure the ice is sufficiently "cured." These delay times may be implemented in hardware (by being built into the control logic), software, or by a combination of both hardware and software. The improved sensor and control concepts offer their own benefits and may be used separately or together.
The present invention provides an improved system and method for sensing of ice, particularly applicable in the control of ice thickness in automatic ice-making machines. The ice-making machine may be of the conventional type using a cold plate with water flowing over it. A thermistor bead temperature sensor is encapsulated in a metal housing, which is in turn mounted on a carrier. The position of the carrier is adjustable relative to the cold plate. The control system has several variable delays or time durations which optimize system performance: 1. Minimum harvest time delay, relative to the start of the ice-making cycle; 2. Threshold persistence time delay, requires that the signal sensor persists above the harvest threshold value for a certain amount of time (referenced to when the threshold is first exceeded), before harvesting may begin; 3. Harvesting delay is an optional delay provided give the option of making sure the ice is sufficiently "cured." These delay times may be implemented in hardware (by being built into the control logic), software, or by a combination of both hardware and software. The improved sensor and control concepts offer their own benefits and may be used separately or together.
