Patent Publication Number: US-4148457-A

Title: Ice cube tray

Description:
BACKGROUND OF THE INVENTION 
     Ice cube trays utilized for forming ice cubes conventionally comprise a body having one or more rows of cavities into which the water is introduced for freezing. In most ice cube trays that are conventionally used, the ice cubes are removed by inverting the tray and applying heat such as hot water to cause the ice cubes to fall out of the tray, by flexing the tray, or by actuating some mechanism to loosen the ice cubes. 
     It has heretofore been suggested that selective removal of ice cubes from a tray without affecting the remaining ice cubes might be achieved by having the cavities formed with arcuate bottom surfaces or walls so that by manipulation of a single ice cube a rotating motion is applied to the ice cubes permitting its removal without inverting the tray. Such ice cubes are found in the art as for example in U.S. Pat. Nos. 1,868,503, 1,889,481, 2,269,642, 2,769,742, and 3,120,112. 
     One of the problems with respect to such ice cube trays is that in filling or in the case where the ice cube tray is tilted before freezing, the water tends to overflow from one cavity to another and in some instances causes a frozen connection between adjacent cavities that is difficult to break loose in attempting to remove one or more ice cubes and cracking or shattering of the tray often results. The problem is even more critical where the tray is made of plastic and the water tends to flow more readily from one cavity to another or in wherein communication is provided between cavities intentionally to insure filling of the cavities such as in U.S. Pat. Nos. 1,868,503 or 3,120,112. 
     Accordingly among the objects of the invention are to provide a plastic ice cube tray wherein the ice cubes can be readily removed. 
     SUMMARY OF THE INVENTION 
     In accordance with the invention, the tray is made of injection molded plastic or pressure die cast metal or sheet metal and depressions are formed in the top wall at the juncture with the bottom wall or side walls of each cavity of the ice cube tray to form water level control surfaces to maintain the water level below the top surface, thereby preventing the water from overflowing and freezing on the top surface. The thickness of the tray material is such that the tray is sufficiently pliable to permit twisting of one end of the tray relative to the other to break the seal between the frozen ice cubes and the walls of the tray. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a plan view of an ice cube tray embodying the invention. 
     FIG. 2 is a part section side elevation view of the ice cube tray. 
     FIG. 3 is a fragmentary sectional view on an enlarged scale taken along the line 3--3 in FIG. 1. 
     FIG. 4 is a fragmentary sectional view on an enlarged scale taken along the line 4--4 in FIG. 1. 
     FIG. 5 is a fragmentary plan view of a modified form of ice cube tray. 
     FIG. 6 is a fragmentary sectional view taken along the line 6--6 in FIG. 5. 
     FIG. 7 is a part sectional view of the modified form of the ice cube tray taken along the line 7--7 in FIG. 5. 
     FIG. 8 is an end view of a further modified form of the ice cube tray. 
    
    
     DESCRIPTION 
     Referring to FIGS. 1-4, the ice cube tray 20 embodying the invention is made from a single body of plastic material such as polyethylene and is preferably made by injection molding, vacuum forming of plastic or pressure die cast metal or sheet metal in order to acheive the configurations and relatively thin uniform thickness as well as the specific construction of the invention. The thickness of the tray material is such that the tray is sufficiently pliable to permit twisting of one end of the tray relative to the other to break the seal between the frozen ice cubes and the walls of the tray. The ice cube tray 20 comprises a top wall 21 having a flat top surface and a peripheral flange 22. 
     The body is of generally uniform thickness throughout and further comprises a plurality of openings 25 herein shown as six sided and generally diamond shaped. A bottom wall 26 and side walls 27 are associated with each opening 25 to define a cavity. The openings 25 extend in two longitudinally spaced parallel rows along the length of the tray 20. 
     Each bottom wall 26 is cylindrical in shape and of generally uniform width and is connected to the side wall 27 by arcuate corner portions 28, the side walls 27 extending upwardly to the periphery of the openings 25. 
     In accordance with the invention depressions 30 are formed in the top surface 21 at the juncture of the upper edge of each bottom wall 26 with the top surface to form overflow passages having a base wall 31. At least some of the depressions 30 extend thru peripheral lip 22. The juncture of the bottom wall 26 and base wall 31 is preferably a sharp edge S sufficient to prevent water that flows out of each cavity from accumulating and freezing at the edge. Since the depressions prevent filling of the cavities above base walls 31, the water cannot overflow onto top surface 21 and freeze in a manner to prevent or defer removal of the ice cubes. The center of the radius curvature of each bottom wall is preferably at the bottom of depressions 30 or above. 
     It can be seen that each of the cavities formed by the bottom wall 26 and side walls 27 is spaced longitudinally from the other and the side walls 27 of one cavity are spaced from the side walls 27 of the adjacent cavity. 
     In the form of the invention shown in FIGS. 5-7, the depressions 32 are formed at the juncture of the top surface 21a and side walls 27a and depressions 33 are formed at the juncture of the inner upper edges of bottom walls 26a and the top surface. Sharp edges S&#39; are provided only at the juncture of the depressions 33 and the bottom walls 26a and have a sharpness sufficient to prevent water that flows out of each cavity from accumulating and freezing at the edge. 
     Depressions 34 are also provided at diagonally opposed portions of the ends of the top wall and lip 22a to permit overflow. In practice, the thumbs of a user cover the depressions to permit carrying the tray filled with water, without spilling the water. 
     In either form, the shape of depressions 30, 31, 32, 33, 34 may be rectangular as shown in FIGS. 2, 6 and 8 or arcuate as shown in FIG. 7. 
     In each of the forms of the invention, one of the important features of the invention comprises the arrangement wherein the depressions are formed at the juncture of the top surface and side walls or bottom wall. When force is applied to one end of each ice cube to remove it, it is readily disconnected from the ice cube tray; as contrasted to an arrangement wherein the ice formed along the top surface makes it difficult to remove the cube by applying a force to one end thereof. The provision of depressions 30, 32, 33, 34 facilitates making of the tray by vacuum forming of plastic or drawing sheet metal by allowing for flow of material into position to form the ice cube cavities.