Patent Application
20090308085
The present disclosure generally relates to an automatic icemaker assembly for a refrigerator. More specifically, the present disclosure relates to an automatic icemaker assembly for rapidly harvesting ice.
A conventional automatic icemaker assembly disposed in a residential refrigerator typically has three major subsystems: an icemaker; a bucket with an auger and ice crusher; and a dispenser insert in a freezer door that allows the ice to be delivered from the bucket to a cup without opening the door. The designs of most conventional icemaker systems use substantial portions of the freezer volume, typically 25%-30%.
The icemaker includes a metal mold that makes batch ice (i.e., between six to ten ice cubes at a time). The mold is filled with water at one end and the water evenly fills ice cube sections through weirs (shallow parts of the dividers between each cube section) that connect the sections. Opening a valve on a water supply line for a predetermined period of time usually controls the amount of water. The temperature in the freezer compartment is usually between about −10° F. to about +10° F. The mold is cooled by conduction with the freezer air, and the rate of cooling is enhanced by convection of the freezer air, especially when an evaporator fan is operating. A temperature-sensing device in thermal contact with the ice cube mold generates temperature signals and a controller, monitoring the temperature signals indicates when the ice is ready to be removed from the mold. When the ice cubes are ready, a motor in the icemaker drives a rake in an angular motion. The rake pushes against the cubes to force them out of the mold. A heater on the bottom of the mold is turned on to melt the interface between the batch ice and the metal mold. When the interface is sufficiently melted, the rake is able to push the cubes out of the mold.
After the ice is harvested, a feeler arm, usually driven by the same motor as the rake, is raised from and lowered into the storage bucket. If the arm cannot reach its predetermined low travel set point, it is assumed that the ice bucket is full and the icemaker will not harvest until more ice has been removed from the bucket. If the feeler arm returns to its low travel set point, the ice making cycle repeats.
The ice storage bucket holds and transports ice to the dispenser in either crushed or whole cube form. If a user requests ice at the dispenser, a motor drives an auger that pushes the ice to the front of the bucket where a crusher is located. The position of a door, controlled by a solenoid, determines whether or not the cubes will go through the crusher or by-pass it and be delivered as whole cubes. The crushed or whole cubes then drop into the dispenser chute. The dispenser chute connects the interior of the freezer with the dispenser and usually has a door, activated by a solenoid, that opens when the user requests ice. The dispenser has switches that permit the user to select crushed or whole cubes, or water to be delivered to the glass.
The conventional icemaker has certain drawbacks. The conventional icemaker assembly is costly due to the controls necessary for making batch ice from a single ice mold. There is undesirable noise associated with the conventional icemaker. For example, a loud hiss noise is created by the burst of water into the batch ice mold, and by the tumbling of the batch ice into the storage bucket. There is also a delay in the forming and harvesting of batch ice. This is because, on the conventional icemaker, the entire ice mold is heated so the ice located in each ice cube section can be simultaneously harvested therefrom. In order to create additional ice, the entire mold has to be cooled before water is dispensed into the ice mold. The water is then frozen and the ice mold is again heated. This temperature cycling causes a time delay in harvesting ice. Further, because the entire ice mold has to be heated, the conventional icemaker requires additional energy.
Accordingly, there is a need in the art for an improved icemaker assembly for a refrigerator.
In accordance with one aspect, an icemaker assembly disposed within a refrigerator is configured for continuous freezing of water and continuous harvesting of ice. The icemaker assembly comprises a rotating ice mold having a plurality of ice forming compartments. A water distributor is operably disposed above the ice mold for supplying water individually to each of the plurality of ice forming compartments. The water distributor supplies the water at a flow rate which is dependent on a rotational speed of the ice mold. The ice mold is rotatable such that each ice forming compartment is movable to a first position for receiving water from the water distributor and movable to a second position for harvesting ice. At the first position, each ice forming compartment is at a first temperature for rapidly freezing the water received from the water distributor. At the second position, each ice forming compartment is at a second, higher temperature for releasing the ice therein.
In accordance with another aspect, an icemaker assembly for a refrigerator including a fresh food compartment and a freezer compartment is provided. The icemaker assembly is disposed in one of the fresh food compartment and the freezer compartment of the refrigerator. The icemaker assembly comprises a housing and an ice mold rotatably disposed within the housing. The ice mold includes a plurality of compartments in which ice is formed. The ice forming compartments are disposed about an outer periphery of the ice mold. A water distributor is connected to the housing and disposed above the ice mold for providing a supply of water separately to each ice forming compartment. A cooling mechanism is thermally connected to one of the housing and the ice mold for cooling each ice forming compartment and flash freezing the water received in each ice forming compartment from the water distributor. A stationary heater is thermally connected to the ice mold for separately melting an interface between the ice and each ice forming compartment. The icemaker assembly is configured for continuous freezing of water and continuous harvesting of ice.
In accordance with yet another aspect, a method of continuous freezing of water and continuous harvesting of ice for a refrigerator is provided. The method comprises rotating an ice mold, the ice mold including a plurality of compartments in which ice is formed. Each ice forming compartment is rotated through a first position and a second position. Water is supplied separately to each compartment at the first position. The water received in each compartment at the first position is flash frozen. Each compartment at the second position is heated to release the ice therein.
Referring now to the drawings, wherein like numerals refer to like parts throughout the several views,
Each ice forming compartment 122 includes a first surface 130, a second surface 132 and an arcuate third surface 134, which connects the first and second surfaces. As shown in
The ice mold 120 can be formed of a rigid material having a low thermal mass. For example, the rigid material for the ice mold having a low thermal mass can be selected from a group of materials consisting of polypropylene, polyethylene, ABS and metals. The rigid material can have a thickness of about 0.020 inches. This allows a significant portion of thermal mass to be predominantly in the water. In that instance, the time required to harvest the ice in each ice forming compartment 122 is primarily determined by the latent heat of fusion of the water rather than the specific heat of the ice mold.
As is well known, the latent heat of fusion, also known as the standard enthalpy of fusion or specific melting heat, is the amount of thermal energy which must be absorbed or evolved for one mole of a substance to change states from a solid to a liquid or vice-versa. The specific heat is the amount of heat per unit mass required to raise the temperature by 1° C. The latent heat of fusion can be observed if you measure the temperature of water as it freezes. For example, if the ice mold 120 is held at a temperature below the freezing temperature of water (i.e. 0° C. or 32° F.), the temperature of the water in each ice forming compartment 122 will fall steadily until it drops just below the freezing point. The temperature of the water then rebounds and holds steady while the water crystallizes. The temperature stops falling at (or just below) the freezing point due to the latent heat of fusion. The energy of the heat of fusion must be withdrawn (the liquid must turn to solid) before the temperature can continue to fall. Once completely frozen, the temperature will fall steadily again.
A water distributor 170 is operably disposed above first opening 114 of the housing 110 and the ice mold 120 for supplying water individually to each of the plurality of ice forming compartments 122. The flow rate of the water supplied from the water distributor is dependent on a rotational speed of the ice mold and the rate of freezing of the water in each ice forming compartment. The water distributor includes a nozzle 176 which provides a supply of water directly into each ice forming compartment 122. In the depicted embodiment, the water is provided as an intermittent drip. Particularly, water is supplied from the nozzle 176 at a low rate that cannot sustain continuous flow due to capillary forces on the nozzle. Water drops should be large enough to prevent freezing when falling from the nozzle to the ice mold 120. A heater 180, which can be a resistance heater, heats the nozzle 176 to prevent freezing of the intermittent drip supply of water. The heater can be located above the first opening 114 of the housing 110 and can at least partially surround a section of the nozzle 176. The heater is spaced from the housing 110 to provide for an insulating air space.
The ice mold 120 is rotatable such that each ice forming compartment 122 is movable to a first position for receiving water from the water distributor 170 and movable to a second position for harvesting ice. At the first position, each ice forming compartment 122 is at a first temperature for rapid freezing of the water received from the water distributor 170. At the second temperature, each ice forming compartment 122 is at a second higher temperature for releasing the ice therein. To ensure that the ice to be harvested from each ice forming compartment is completely frozen, an ice ready sensor or detector 200 can be located in the chamber 112 of the housing 110. As shown in
With reference to
An ice storage bin 250 can be located beneath the second opening 116 of the housing 110 and the ice mold 120 for receiving ice harvested from each ice forming compartment 122. A fullness detector 260 can be attached to one of the housing 110 and the ice storage bin 250. The fullness detector can be electrically connected to the controller 210. The fullness detector detects a level of ice in the ice storage bin 250. Depending on a level of ice in the ice storage bin, the fullness detector can slow or stop rotation of the ice mold 120 when the level of ice within the ice storage bin 250 is at a predetermined level. Thus, rotation of the ice mold 120 is dependent on the level of ice in the ice storage bin 260. The fullness detector can be any known variety of sensor such as a feeler connected to a switch, an LED beam, a capacitive sensor, and the like. As indicated previously, the fullness detector is electrically connected to the controller 210. Thus, the fullness detector can generate a first signal to the controller to slow or stop rotation of the ice mold when the level of ice within the ice storage bin is at a first level. The fullness detector can generate a second signal to the controller to start or speed up rotation of the ice mold when the level of ice within the ice storage bin has dropped below the first level.
A stationary heater 280 is positioned at or near the second position of each ice forming compartment 122 to separately heat each ice forming compartment to the second temperature. By individually heating each ice forming compartment, the intermittent heater 280 can operate at a low wattage, such as 10 watts. The heater 280 is in thermal proximity to the ice mold 120 for heating an interface between the ice and the surfaces 130, 132, 134 of each ice forming compartment 122. As shown in
In operation, the icemaker assembly 100 provides continuous freezing of water and continuous harvesting of ice for a refrigerator. The ice mold 120 is configured to continuously rotate wherein each of the ice forming compartments 122 is rotated through the first position and the second position. Water is separately supplied to each ice forming compartment 122 at or near the first position by the water distributor 170. The ice mold is continuously cooled and subsequently heated as the ice mold rotates from the first position to the second position. At or near the first position, each ice forming compartment 122 is at a predetermined first temperature such that the water received in each ice forming compartment at the first position is rapidly or flash frozen. The heater 280 heats each ice compartment 122 at or near the second position to release the ice therein. A nozzle 176 produces an intermittent drip supply of water and the flow rate of the drip supply of water is controlled so that the flow rate is dependent on the rotational speed of the ice mold 120. The ice harvested from each ice forming compartment 122 is collected in the ice storage bin 250. The rotational speed of the ice mold 120 can be dependent on a level of ice collected in the ice storage bin.
With reference to
As shown in
Alternatively, as shown in
As indicated previously, the ice mold 120 is at a predetermined temperature such that the water received in each ice forming compartment 122 from the water distributor 170 is rapidly or flash frozen within the ice forming compartment. This allows for the formation of clear ice (see
With reference to
As shown in
A water distributor 170′ is operably disposed above the housing 110′ and the ice mold 410 for supplying water individually to each of the plurality of ice forming compartments 412. The flow rate of the water supplied from the water distributor is dependent on a rotational speed of the ice mold. An ice ready detector 200′ can be located in the housing for detecting that the ice to be harvested from each ice forming compartment 412 is completely frozen. A stationary heater 280′ separately heats each ice forming compartment to melt an interface between the ice and the surfaces of the ice forming compartment. As shown in
A drive mechanism 440 is operably connected to the ice mold. In the depicted embodiment, the drive mechanism is a slip clutch 442. The slip clutch is operably engaged to an axle 446 of the ice mold 410. The axle has one end 450 rotatably secured to the housing 110′ and a second end 452 operably coupled to the drive mechanism. A solenoid 456 is operable connected to the slip clutch. The drive mechanism can be electrically connected to the controller so that the controller can monitor the rotational speed of the ice mold 410.
Similar to the previous embodiment, the ice mold 410 is configured for continuous rotation and harvesting of ice. However, unlike ice mold 120 which is rotatable via the drive mechanism 220′, ice mold 410 rotates via weight of ice formed in each ice forming compartment 412. Particularly, as water drips into each ice forming compartment 412 and is rapidly frozen therein, the weight of the ice causes the ice mold 410 to rotate slowly in one direction. Since an ice forming section 460 of the ice mold will be slightly heavier than a water receiving section 462 of the ice mold, the ice mold will turn or rotate itself. As ice is being formed in each ice forming compartment 412, gravity is pulling the ice downward towards the ice storage bin (not shown) located beneath the ice mold 410. This causes the ice mold to rotate. If the ice ready detector 200′ detects that the ice to be harvested from each ice forming compartment 412 is not completely frozen, the detector will send a signal to the controller 210′. The controller actuates the solenoid 456. The solenoid engages the slip clutch 442 which, in turn, stops rotation of the ice mold 410.
A fullness detector 470 is connected to the ice mold 410 for detecting a level of ice in the ice storage bin. The fullness detector stops rotation of the ice mold when a level of ice within the ice storage bin is at a predetermined level. In the depicted embodiment, the fullness detector 470 includes a plurality of projections 472 which extend outwardly from the ice mold 410. Each projection extends at least partially into the ice storage bin. A contact of one of the projections with ice located in the ice storage bin will stop rotation of the ice mold. As the ice drops below the predetermined fullness level, gravity will again cause the ice mold 410 to rotate. If the rotation of the ice mold is slowed or stopped by the level of ice in the ice storage bin, the controller 210′ will communicate with the water distributor 170′ and the heater 280′. The water distributor will adjust its flow rate to correspond to the rotational speed of the ice mold and the controller 210′ will adjust the timing of the intermittent heating of the heater to correspond with the rotation of the ice mold.
With reference to
The icemaker assembly 500 is similar to the icemaker assembly 100 of
The ice forming surfaces of the respective ice forming compartments 122′ and 512 of the first and second ice molds 120′ and 510 are angled away from each other such that the ice formed in each ice forming compartment will slide out of the ice forming compartment away from the other ice mold. A drive mechanism 220′ is coupled to a single axle 550 which extends through both the first and second ice molds. A single ice fullness detector 560 is provided on the housing 502 for detecting a level of ice in an ice storage bin (not shown) located beneath the housing.
With reference to
In this embodiment, the icemaker assembly 600 includes a housing 602 for housing a conveyor assembly 610 and a drive mechanism (not shown) operably coupled to the conveyor assembly. A water distributor 170′ is positioned adjacent to the conveyor assembly. An ice storage bin (not shown) is located beneath the housing of the icemaker assembly. A controller (not shown) can be electrically coupled to the drive mechanism and water distributor.
The conveyor assembly comprises at least a front roller 620, a rear roller 622 and a continuous conveyor belt 630 fitted in tension about the front and rear rollers. In one embodiment, the conveyor belt can be made of a flexible polymer. A plurality of individual ice forming compartments 632 are disposed within or upon the conveyor belt for creation of individual ice cubes therein. The ice forming compartments are molded directly into the material of the conveyor belt. Alternatively, the ice molds can be made of a rigid material and are fixedly attached to the conveyor belt. The rigid material can be, for example, polypropylene, polyethylene, and ABS, or the like. The conveyor belt dimensions can be dependent upon the size of the refrigerator and the desired ice cube output for the icemaker assembly 600. The dimensions of an individual ice forming compartment 632 can vary depending on the size of the ice cubes desired.
The drive mechanism is drivingly coupled to the conveyor assembly 610. When energized, the drive mechanism drives the rear roller 622 (or alternatively, the front roller 620) causing the conveyor belt to rotate rear to front. A portion of the ice forming compartments 632 will face generally upward during ice formation. As the conveyor belt rotates forward over the front roller 620, a portion of the ice forming compartments face generally downward and ice frozen within are gravity fed into the ice storage bin located beneath the housing. A heater 280′ is provided adjacent the second roller 622 such that the heater can heat each individual ice forming compartment to melt the interface between the ice formed therein thereby allowing the ice to drop out of the conveyor belt and into the ice storage bin. The water distributor 170′ is positioned generally above the ice forming compartment. The water distributor is actuated when a belt position sensor (optical, mechanical, proximity switch, or the like) generates a signal to a controller (not shown) indicating that the belt is in the correct position for refill. The drive mechanism is energized when the fullness of ice in the ice storage bin falls below a preset fill level and an ice-ready sensor 200′ generates a signal to the controller that the ice in the ice forming compartment to be delivered is frozen. If a fullness detector 260′ disposed within or about the ice storage bin generates a signal to the controller that the level of ice within the ice storage bin has dropped below a preset fill level, a cycle is initiated and the drive mechanism advances the conveyor belt 630 one ice forming compartment at a time such that water can be delivered separately into an empty ice forming compartment.
With reference now to
Generally, the refrigerator 700 includes an evaporator (not shown) which cools the fresh food compartment and the freezer compartment. Normally, the fresh food compartment will be maintained at about 40° F. and the freezer compartment will be maintained at about 0° F. In order to rapidly freeze the water in the rotating ice mold 120, the chamber 112 defined by the housing of the icemaker assembly is maintained at a temperature approximately about 0° F.
A cooling mechanism or cold air duct 730 extends between the freezer compartment 714 and the icemaker assembly 100. The cold air duct has a lower air inlet 732 between the freezer compartment and an upper outlet 734 connected to the housing. A fan (not shown) draws cold air from the freezer department 714 and forces the air into the icemaker assembly so as to facilitate ice making. An air deflector 750 is provided in the housing 110 of the icemaker assembly 100 to direct the cold air from the freezer compartment to the ice mold 120 as the ice mold rotates to the first position. This insures that the temperature of each ice forming compartment 122 is at or about the first temperature as each ice forming compartment rotates to the first position. The deflector 750 also prevents the cold air from affecting the operation of the heater (not illustrated) which is located on the other side of the ice mold. Although, it should be appreciated that alternative manners for cooling the ice mold 120 to the first temperature are contemplated. An auger 780 is provided beneath the icemaker assembly to advance ice into the ice dispenser 720.
The carousel concept of the present disclosure insures that the icemaker assembly occupies minimal space in the fresh food compartment. The size of the ice storage bin (located in the ice dispenser) can be reduced to conserve space. Because the icemaker assembly continuously produces and harvests ice, there is less need to hold a significant ice inventory.
It should be appreciated from the foregoing, a method of continuous freezing of water and continuous harvesting of ice for a refrigerator is provided. The method comprises rotating an ice mold, the ice mold including a plurality of compartments in which ice is formed. Each ice forming compartment is rotated through a first position and a second position. Water is supplied separately to each compartment at the first position. The water received in each compartment at the first position is flash frozen. Each compartment at the second position is heated to release the ice therein.
It should also be appreciated that the icemaker assembly of the present disclosure can be less costly than a conventional icemaker assembly because many of the operating controls are already located on a master control for the refrigerator. The material of the ice mold can be less expensive than the conventional die cast body that is used for making batch ice. The forming of a single ice cube from a slow supply of water does not create the undesirable noise associated with the conventional icemaker. There is no delay in the forming and harvesting of ice because the icemaker assembly of the present disclosure is configured to continuously harvest ice. The ice rate is higher than the conventional icemaker because of the lower thermal mass of the ice mold and the ice mold is cooled prior to being filled with water. With the continuous ice making process of the present disclosure, the inefficient heating and cooling time of the conventional icemaker assembly is only associated with a portion of the rotating ice mold (i.e., the empty ice forming compartments). Further, because the icemaker assembly of the present disclosure does not require heating of air to harvest ice, less energy is required.
It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
