Patent Publication Number: US-4727720-A

Title: Combination ice mold and ice extractor

Description:
REFERENCE TO PRIOR ART 
     Prior art ice machines having trays that swing from an upright position for freezing ice to an inverted position have been known in the art. Examples of such machines are shown in U.S. Pat. No. 3,648,964 to Fox, U.S. Pat. No. 3,254,505 to DeTurk, and U.S. Pat. No. 3,892,105 to Bernard. These machines all freeze ice in the ice cube tray and invert the tray to discharge it. These machines are inefficient in operation, complex in structure, subject to malfunction and unreliable. 
     ADVANTAGES OF THE INVENTION 
     No mechanical parts are associated with the evaporator plate 17, the condenser or the thermo-electric module 11 disclosed herein. Heat sink compound (silicon or epoxy), is used to mount the evaporator to thermo-electric module and thermo-electric module to heat sink (or condenser). Because of the open bottom extractor 15, heat transfer is of optimum efficiency, that is, directly from the ice in the extractor to the evaporator 17 and thermo-electric module 11 which are mounted on the heat sink by silicon or epoxy type heat sink materials. Prior machines used film of material on an air gap between moving members. No stress is required to harvest or extract ice from the evaporator 17. Distortion of the evaporator 17 or extractor 15 is not required to harvest ice. The inherent inefficiency of the machine prevents the ice from sticking hard to the extractor 15; that is, heat flowing in from around the end and top of the ice extractor 15 keep ice from freezing hard to the extractor 15. The extractor 15 will be made from either brass, bronze or stainless steel to take advantage of the inherent thermal inefficiency of the machine. That is, the heat conducting quality of metal uses the inefficiency to keep ice from freezing hard to extractor 15. The lip 35 on the ice mold 13 is used to reduce heat transfer from the extractor 15 to the evaporator 17 to enhance the inherent inefficiency, which prevents ice from sticking to the extractor 15. The lip 35 may be molded into the plastic mold form 13 or it may be a piece of, say, silicon gasket between the plastic mold form and evaporator 17 to provide virtually a perfect seal. The extractor 15 has a sharp edge 32 which contacts the ice mold lip 35 or gasket to prevent ice from forming around the edge of the extractor 15 thus preventing the ice cube from hanging up during harvest. The sharp edge 32 firmly (positively) seals against the plastic of lips 35 and will seal against the bottom of the ice mold. The sharp edge comes into intimate contact with the lip 35 of the ice mold, due to the force of the stalled extractor motor 18. The motor 18 is stalled when the extractor is in the ice mold for two reasons: (1) To act as a force for the above and (2) to simplify design to eliminate the need for limit switches or position sensing switches. Several improved features of Applicant&#39;s ice maker are: (1) no lubricating film is required between the evaporator and the heat sink; (2) no large motor is required to create distortion (twisting) of the evaporator to harvest the ice; (3) rotary motion of the evaporator is not required; (4) the evaporator in this machine is flat and stationary; and, (5) no moving parts are needed in the evaporator or condenser; it is of solid state construction. Items 1 through 4 above would apply if the design were used with typical refrigerant systems using freon and compressors, or expanding gasses. 
     The dual wall 13, made up of walls 13&#39; and 13&#34; of the ice mold is designed to give thermopane type insulation to limit inefficiency to practical levels (desirable levels). There are two such dual wall insulators which are the top wall insulator which prevents excessive heat from warming the water from the ambient air and the lower wall insulator 113, with adjacent space, which reduces heat from entering the evaporator from the aluminum heat sink type condenser. The location of the mounting holes in conjunction with the offset 38 of the lower dual wall insulators forms an inherent plastic spring to hold down the evaporator thermo-electric module 11, provide constant force between evaporator and thermo-electric module 11 to condenser to maximize heat transfer and efficiency, and provide water and air tight seal to prevent contamination and/or corrosion of thermo-electric module, evaporator and condenser. 
     STATEMENT OF THE INVENTION 
     Applicant has provided a combination ice mold and ice extractor efficient in operation, simple in construction and reliable. The ice in Applicant&#39;s machine is formed in a mold with tapered sides for easy extraction from a molded plastic device which can also have the feature of molding any specific shape that is, for example, initials, corporate logos, or shapes like animals or the state of Texas, and the like, all of which are referred to as things. The device extracts the ice from the ice mold by rotating it and dropping the ice into an ice container or bin. The ice mold extractor is actuated by a motor driven cam or reversible motor controlled by either an electronic or mechanical timer. Ice is formed in the ice mold-extractor on top of a flat thermoelectric freezer module and after a predetermined period of time, a defrost cycle is initiated in which the ice is melted from the thermoelectric module or evaporator and the ice mold extractor 15 rotates and removes the ice from the ice maker section and dumps it into the ice storage bin through chute 16. The extractor rotates from 90° to 180 ° depending upon the design of the specific model and returns back to the initial position and the freezing cycle is re-initiated to form the next ice cube. Intricate shapes or logos may require no lip on mold such that defrosting or harvesting the ice from extractor is aided by heat from the defrost cycle. 
     The ice mold 13 has an open bottom closed by evaporator plate 17, as recited in original claim 21, which overlies the opening in the bottom of the ice mold forming an open topped container. The lip 35 of the ice mold 13 engages the evaporator plate 17 and forms substantially a perfect seal. The open bottomed ice extractor 15 fits into the opening in the bottom of the ice mold 13 in the freezing position and the water level in the ice mold 13 stands up over the top of the flange of the ice extractor. The water level of water in the ice mold is controlled by the float 23. Heat from the water in the ice extractor is absorbed by the evaporator plate 17 and the water in the ice extractor is therefore frozen from the bottom upwardly. Relatively warm water in the ice mold surrounds the ice extractor 15 and keeps the water of the extractor relatively warm. Therefore, ice does not freeze hard to the inside surface of the ice extractor walls and does not freeze to the outside of the ice extractor at all. 
     Moreover, the path for heat to flow from the evaporator plate 17 to the walls of the ice extractor is further reduced by the sharp edges 32 of the ice extractor, as shown in FIG. 2. This, coupled with the fact that the heat is supplied to the outside of the ice extractor by the warm water in the ice mold around the outside of the ice extractor, prevents ice from freezing to the ice extractor. Thus, the ice freezes in the ice extractor from the bottom upwardly as heat is carried away by the evaporator plate but does not freeze hard to the walls of the ice evaporator. 
     The harvest cycle is initiated when ice fills the extractor. When the ice harvest cycle is initiated, the electrical power to the electrothermo module 11 is turned off at control 30, and since the evaporator plate&#39;s temperature rises to water temperature, there is no longer a heat gradient and heat no longer continues to flow from the water in the ice extractor to the evaporator plate 17 and the ice is released from the evaporator plate. The motor 18 then swings the ice extractor from the position A through the position B to the position C. Heat from the ambient warm air then flows through the metal walls of the ice extractor 15 and melts loose any ice that may be adhering to the inside of the ice extractor and ice from the ice extractor then falls by gravity into the ice chute 16. 
     The ice extractor is preferably made up of a good thermo-conductor for example, aluminum, brass, bronze or stainless steel, to prevent the ice cube from freezing very hard to it. This is accomplished by the fact that the water surrounding the cube and extractor is warmer and not frozen and therefore allows heat to flow into the extractor preventing hard freezing of the cube to the extractor. This provides reliable and easy ice extraction and also dumping as ambient heat provides a slippery water film to develop during the harvest or defrost cycle to allow the ice to simply fall out of the extractor. 
     OBJECTS OF THE INVENTION 
     It is an object of the invention to provide an improved ice making machine for making a small number of cubes. 
     Another object of the invention is to provide an ice making machine that is simple in construction, economical to manufacture and simple and efficient to use. 
     Another object of the invention is to provide a combination ice molder and ice extractor. The ice is formed in a mold with tapered sides for easy extraction and the device extracts the ice from the ice maker by rotating it and dropping the ice into an ice container or bin. The ice is formed on a thermo-electric freezer module which forms the bottom of the ice mold. 
     With the above and other objects in view, the present invention consists of the combination and arrangement of parts hereinafter more fully described, illustrated in the accompanying drawing and more particularly pointed out in the appended claims, it being understood that changes may be made in the form, size, proportions, number of cubes and minor details of construction without departing from the spirit or sacrificing any of the advantages of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is longitudinal cross sectional view of the machine. 
     FIG. 2 is another longitudinal cross sectional view partial broken away showing the ice extractor in a position over the ice chute as shown in phantom lines in the ice cube mold and in further phantom line position in an intermediate position between the ice mold and the ice cube chute. 
     FIG. 3 is an isometric view of the ice cube machine according to the invention. 
     FIG. 4 is a sectional view of the ice extractor. 
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     Now with more particular reference to the drawings, I show a combination ice cube mold and extractor 10 comprising a thermo-electric module 11, a heat sink 12 supporting the module 11 and ice extractor 15 above the thermo-electric module 11. A water supply tank 14 is supported on the machine alongside of the ice mold 13 and float valve 24 controls the flow of water from a float tank 22. The water level in the float assembly tank 22 is maintained at the proper level to maintain a water level in the ice mold 13. This is accomplished by the float 23 which controls valve 24 from the supply line 25. The supply line 25 may be a water tap from a city main or the like or from gravity fed tank. The ice mold 13 has a cavity in its bottom and the evaporator 11 forms a closure for the opening. The float tank 22 is connected through the water line 26 to the space inside the ice mold 13 and the level of water in the tank is maintained equal to the level in the mold 13. 
     The ice extractor 15 is swingably connected to the shaft 21 of the motor 18. The motor 18 is a reversible motor which will swing the ice extractor 15 from the position A, shown in FIG. 2, through the position B, to the position C where it is inverted over the ice cube chute 16. In this position ice will fall from the mold. The ice extractor 15 has four downwardly and inwardly converging side walls 27, 28, 29 and 30 that terminate in a sharp edge 32 which engages the mold in the refrigeration means so that the ice cube will easily fall out of the extractor when it is in the position C, over the ice cube chute 16. Ambient heat melts the ice loose from the walls 27-30 of the ice mold. Walls 27-30 could be of a greater number of sides or intricately shaped for various other forms. 
     The evaporator plate 17 is supported over top of the thermo-electric module 11 and the evaporator plate 17 forms a bottom for the opening in the mold 13 and conducts heat from the water in the ice mold and extractor to the heat sink. 
     Ice cubes from the ice extractor 15, when it is in the C position, fall into the chute 16 and may drop from there into a suitable ice cube bin. 
     The condenser or heat sink 12 has suitable fins as shown thereon for carrying heat away from the module. The fan 19 circulates air over the fins of the heat sink 12 to remove heat from it. 
     The ice mold 13 has a downwardly facing shoulder 35 which rests on the outer periphery of evaporator plate 17. Ice mold 13 has an outwardly directed flange 38 which has mounting holes 37 which receive studs that extend into heat sink 12. The offset of mounting holes location in conjunction with the offset dual wall insulator prevents excessive heat transfer from the evaporator plate to the ice mold. 
     A suitable electrical control panel 30 connects electricity from twelve volts DC from plug 36. A plug 31 could also be provided to connect the control 30 optionally to a 120 volt AC circuit. 
     The ice maker disclosed herein has the following features and advantages over all prior art known to Applicant: (1) no moving parts are associated with the evaporator or condenser or thermo-electric module; (2) no lubricating film is used for both heat transfer and lubrication. Heat transfer is as efficient as possible, that is, directly from the ice; (3) no stress is required to harvest or extract ice from the evaporator. Distortion of the evaporator or extractor is not required to harvest ice; (4) the inherent inefficiency of the machine prevents the ice from sticking to the extractor; that is, heat flowing in from around end and top keeps ice from freezing hard to the extractor; (5) the extractor will be made from either brass or stainless steel to take advantage of the inherent inefficiency of the machine, that is, the heat conducting quality of metal is used to use inefficiency to keep ice from freezing hard to the evaporator; (6) the lip on the ice mold is to reduce heat transfer the extractor to the evaporator to enhance the inherent inefficiency, which prevents ice from sticking to the extractor. The lip may be molded in the plastic evaporator form or be a piece of, say, silicon gasket between the plastic form and evaporator to provide even better (perfect) seal; (7) the extractor is pointed on the edge which contacts and has latches which provide the spaced legs 40 the ice mold to prevent ice from forming around the edge of the extractor to prevent the ice cube from hanging up in harvest. The point more firmly (positively) seals against the plastic and would undoubtedly seal against the silicon gasket; and (8) the pointed edge comes into intimate contact (seated) on the lip of the ice mold, due to the force of the stalled extractor motor. The motor is stalled for two reasons: (1) to act as a force for the above and (2) to simplify design to eliminate the limit switches (position sensing switches). 
     Improvements over prior art ice makers are that no lubricating film is required, no large motor to create distortion (twisting) of the evaporator to harvest the ice, rotary motion of the evaporator is not required, the evaporator in this approach is flat and stationary and there are no moving parts in the evaporator or condenser. &#34;solid state&#34; electronics is used. Other claims to my invention are that the dual wall of the ice mold is designed to give thermopane type insulation to limit inefficiency to practical levels (desirable levels). There are two such dual wall insulators which are the top wall insulator which prevents excessive heat from warming the water from ambiant air and the lower wall insulator which reduces heat from entering the evaporator from the aluminum heat sink type condenser. The mounting holes location in conjunction with the offset dual wall insulators form an inherent plastic spring to hold down the evaporator thermo-electric module, provide constant force between evaporator and thermoelectric module to condenser to maximize heat transfer and efficiency, and provide water and air tight seal to prevent contamination and/or corrosion of thermoelectric module, evaporator and condenser. 
     The foregoing specification sets forth the invention in its preferred, practical forms but the structure shown is capable of modification within a range of equivalents without departing from the invention which is to be understood is broadly novel as is commensurate with the appended claims.