Efficient ice maker

Abstract

An ice making apparatus includes a tray made of a thermally conductive material which has two opposite sides. Each side has a plurality of cavities for receiving water, when facing up. The water is frozen to form ice units conforming to the shape of the cavities. The cavities are shaped to have a smooth contour and are coated with a non-wetting material. After the water in the cavities in the side of the tray that is facing up is frozen, the tray is rotated such that the ice units are dislodged and are collected in a receptacle. The other side of the tray is now filled with water; the heat of the water flows thermally to the opposite side. An embodiment also includes a mechanically driven finger bar with prongs to dislodge the ice.

1 . Apparatus for making ice units comprising:
 a tray having two opposite sides, each side having a plurality of cavities for receiving water, when the side is facing up, which is to be frozen to form ice units conforming generally to the shape of the cavities; each cavity being coated with a non-wettable coating and being shaped to have a smooth contour with no sharp edges for enabling ice units formed within a cavity to be easily dislodged;   the tray being rotatable such that when the cavities of one side face up to receive water to be frozen, the cavities of the opposite side face down and ice units contained in the cavities facing down are dislodged; and   the tray being formed of a thermally conductive material for enabling the heat of the water added to one side to flow thermally to the opposite side to dislodge ice units.   
     
     
         2 . Apparatus for making ice units as claimed in  claim 1 , wherein the tray material is a metal. 
     
     
         3 . Apparatus for making ice units as claimed in  claim 1 , wherein each cavity is shaped like a spherical cap having gradually widening sides extending from its cap. 
     
     
         4 . Apparatus for making ice units as claimed in  claim 1 , wherein the surface of each cavity is coated with a fluorinated ethylene propylene resin (FEP). 
     
     
         5 . Apparatus for making ice units as claimed in  claim 2 , wherein the tray includes conduits formed between, and interconnecting, the cavities of each side to allow water to flow into all the cavities of each side facing up. 
     
     
         6 . Apparatus for making ice units as claimed in  claim 1  including means attached to the tray for rotating the tray. 
     
     
         7 . Apparatus for making ice units as claimed in  claim 6  further including a mechanism coupled to the tray for mechanically dislodging ice units from the cavities of a side of the tray facing down. 
     
     
         8 . A system for making ice units comprising:
 a tray having two opposite sides, each side having a plurality of cavities for receiving water which is to be frozen to form ice units conforming generally to the shape of the cavities; each cavity being coated with a non-wettable coating and being shaped to have a smooth contour with non sharp edges for enabling ice units formed within a cavity to be easily dislodged;   means coupled to the tray for rotating the tray and dislodging the ice units such that, when the cavities of one side face up to receive water to be frozen, the cavities of the opposite side face down and ice units contained in the cavities facing down are dislodged; and   the tray being formed of a thermally conductive material for enabling the heat of the water added to one side to flow thermally to the opposite side to dislodge ice units.   
     
     
         9 . A system for making ice units as claimed in  claim 8 , wherein the tray material is a metal having high thermal conductivity and low specific heat. 
     
     
         10 . A system for making ice units according to  claim 8 , wherein the surface of the cavities is coated with fluorinated ethylene propylene resin (FEP). 
     
     
         11 . A system for making ice units according to  claim 8 , wherein the cavities are generally shaped like spherical caps which, when facing up, have gradually widening sides. 
     
     
         12 . A system for making ice units according to  claim 8 , wherein each surface of the tray includes conduits formed between the cavities to allow water to flow from a water source and fill the cavities along the side of the tray facing up. 
     
     
         13 . A system for making ice units according to  claim 8 , wherein the means coupled to the tray for rotating the tray and dislodging the ice units includes a mechanism with prongs which can be urged upward to dislodge ice units formed in the cavities of the side of the tray facing down. 
     
     
         14 . A system for making ice units according to  claim 13 , wherein the mechanism with prongs includes a bar mounted on a bumper plate with the prongs extending therefrom. 
     
     
         15 . A system for making ice units as claimed in  claim 13 , wherein the mechanism with prongs is driven by a spring force. 
     
     
         16 . A system for making ice units according to  claim 8 , wherein said cavities are generally dome shaped with sides that slope down smoothly, gradually and continuously, such that there are no corners or straight lines or flat surfaces for the ice units to stick to. 
     
     
         17 . A system for making ice units according to  claim 8 , wherein after ice units are formed in one side of the tray, the tray is rotated 180 degrees so the one side faces down and cavities in the other, opposite, side face up and are filled with water and wherein the heat of the water filling the cavities of the other opposite side warm up the tray to loosen the ice units in the one side and ensure that they are ejected. 
     
     
         18 . A system for making ice units according to  claim 14 , wherein said means coupled to the tray for rotating the tray and dislodging the ice units includes a mechanism to raise and lower the finger bar to clear the rotation of the ice tray. 
     
     
         19 . A system for making ice units according to  claim 8  wherein said means coupled to the tray for rotating the tray includes a motor for selectively causing the tray to rotate at least 180 degrees. 
     
     
         20 . A system for making ice units according to  claim 8 , wherein each side of the tray includes at least two rows of cavities and wherein there is included a dual channel water diverter to concurrently fill the rows with water.