Clear ice maker

Abstract

The present invention is a clear ice maker with an expansion space in a tapered cup below a similarly tapered ice mold. The expansion space forces the mold to lift relative the cup when freezing is complete. Sawtooth protrusions in the cup may be provided to enable line contact between the cup and mold. The mold is easy to remove from the cup to release the ice shape.

I claim: 
     
         1 . A clear ice maker, comprising:
 an outer container formed of a thermal insulating material and having walls defining a top opening in communication with an inner cavity;   a receiver formed of a rigid material and located within the inner cavity of the outer container;   the receiver having at least one cup formed by interior walls and edges defining an open top;   an ice mold inserted into the cup, and having a bottom exterior wall; and   with the cup and ice mold sized to provide an expansion space in a lower section of the cup below the bottom exterior wall of the ice mold, the expansion space sized to lift the ice mold relative the cup when water in the expansion space freezes into ice.   
     
     
         2 . The clear ice maker of  claim 1  with the insulating material being polystyrene foam. 
     
     
         3 . The clear ice maker of  claim 1  with the receiver being removably located in the inner cavity. 
     
     
         4 . The clear ice maker of  claim 1  with the receiver being fixed in the inner cavity. 
     
     
         5 . The clear ice maker of  claim 1  with cup interior side walls being tapered outwardly from an interior bottom wall to the open top. 
     
     
         6 . The clear ice maker of  claim 1  with the cup interior walls including side walls having a plurality of sloping, horizontal, shallow sawtooth protrusions. 
     
     
         7 . The clear ice maker of  claim 6  with the sawtooth protrusions spaced about 4 mm apart and having a depth of about 0.2 mm. 
     
     
         8 . The clear ice maker of  claim 1  with the ice mold formed of pliable material. 
     
     
         9 . The clear ice maker of  claim 1  with the ice mold consisting of two mirror-image halves inserted into the cup. 
     
     
         10 . The clear ice maker of  claim 1  with the ice mold further including exterior side walls tapered for parallel interfitment with tapered cup interior side walls. 
     
     
         11 . The clear ice maker of  claim 6  with the ice mold further including exterior side walls tapered for parallel interfitment with tapered cup interior side walls adjacent the sawtooth protrusions. 
     
     
         12 . A clear ice maker, comprising:
 an outer container formed of a thermal insulating material and having walls defining a top opening in communication with an inner cavity;   a receiver formed of a rigid material and located within the inner cavity of the outer container;   the receiver having at least one cup formed by interior walls and edges defining an open top;   an ice mold inserted into the cup, and having a bottom exterior wall;   with cup interior side walls being tapered outwardly from an interior bottom wall to the open top;   with the cup interior side walls having a plurality of sloping, horizontal, shallow sawtooth protrusions; and   with the ice mold further including exterior side walls tapered for parallel interfitment with the tapered cup interior side walls; and   with the cup and ice mold sized to provide an expansion space in a lower section of the cup below the bottom exterior wall of the ice mold, the expansion space sized to lift the ice mold relative the cup when water in the expansion space freezes into ice.   
     
     
         13 . The clear ice maker of  claim 12  with the insulating material being polystyrene foam. 
     
     
         14 . The clear ice maker of  claim 12  with the receiver being removably located in the inner cavity. 
     
     
         15 . The clear ice maker of  claim 12  with the receiver being fixed in the inner cavity. 
     
     
         16 . The clear ice maker of  claim 12  with the sawtooth protrusions spaced about 4 mm apart and having a depth of about 0.2 mm. 
     
     
         17 . The clear ice maker of  claim 12  with the ice mold formed of pliable material. 
     
     
         18 . The clear ice maker of  claim 17  with the ice mold formed of pliable silicone rubber having a Shore A durometer in the range of about 30 to about 40. 
     
     
         19 . The clear ice maker of  claim 12  with the ice mold consisting of two mirror-image halves inserted into the cup. 
     
     
         20 . A clear ice maker, comprising:
 an outer container formed of polystyrene foam and having walls defining a top opening in communication with an inner cavity;   a receiver formed of a rigid material and removably located within the inner cavity of the outer container;   the receiver having at least one cup formed by interior side walls, an interior bottom wall, and edges defining an open top;   the cup interior side walls being tapered outwardly from the interior bottom wall to the open top, and the cup interior side walls having a plurality of sloping, horizontal, shallow sawtooth protrusions spaced about 4 mm apart and having a depth of about 0.2 mm;   an ice mold formed of pliable silicone rubber having a Shore A durometer in the range of about 30 to about 40, the ice mold consisting of two mirror-image halves inserted into the cup, the ice mold further including exterior side walls tapered for parallel interfitment with the tapered cup interior side walls adjacent the sawtooth protrusions, and the ice mold having a bottom exterior wall; and   with the cup and ice mold sized to provide an expansion space in a lower section of the cup below the bottom exterior wall of the ice mold, the expansion space sized to lift the ice mold relative the cup when water in the expansion space freezes into ice.