US2497743A - Ice tray - Google Patents

Description

Feb. 14, 1950 J. H. ROETHEL ICE TRAY Filed May 22, 1948 INVENTOR. J2? /x Rad/ha Patented Feb. 14, T9550 UNITED STATES PATENT OFFICE' Roethel Engineering Corporation,

Detroit,

Mich, a corporation of Michigan Application May 22,1948, Serial No. 28,541

3 Claims.

This invention relates to liquid freezing trays and particularly to a tray of the general type having a. pan-like receptacle within which ice cubes or blocks of frozen substances are molded through the medium of grid or division members connecting the side walls of the tray.

An object of the invention is to provide an ice tray or the like which may be molded as a unit from plastic material, such as polyethylene plastic or the like, to provide transverse grid or divider members joined to the bottom and side walls of the tray, and in which the bottom of the tray may be made relatively thin and capable of providing maximum freezing contact with the "evaporator shelf, the improved construction being such as to permit flexing or twisting of the receptacle so as to easily loosen or eject the ice blocks.

A further object of the invention is to form the pan or receptacle of the tray and its transverse grid or divider members in one piece from plastic material, preferably polyethylene or equivalent material, the grid members of the tray being tapered so as to increase in thickness toward the bottom of the tray and the side walls of the tray decreasing in thickness toward the bottom of the tray, thus enabling a thin bottom to be used while facilitating removal of the ice cubes when the tray is flexed or torsionally twisted, the improved construction having the further advantage of assisting in maintaining the tray in proper shape.

Still another object of the invention is to provide the upper edges of the side walls of the tray receptacle with notches or depressed portions which not only serve as overflow openings to control the height of the water level in the tray when filled but also increase the flexibility of the tray to facilitate bending or flexing thereof ,when removing the ice cubes.

tion it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

In the drawings there is illustrated, by way of example, an ice tray comprising a pan-like receptacle adapted to contain water and constructed with a series of transverse grid or dividing members integrally connecting the side walls of the tray or receptacle together and by means of which a number of ice cubes or blocks may be produced when the tray is supported within the ice freezing compartment of a refrigerator.

The pan-like receptacle I0 is generally rectangular in shape and in the present instance is relatively narrow to produce a single row of ice cubes or blocks corresponding in widths to the width of the receptacle. The pan or receptacle i0 is molded in one piece from polyethylene or equivalent plastic material to provide a fiat bottom ll terminating in parallel upright side walls l2 and rear and front upright walls l3 and H respectively which are integral with the bottom and extend continuously around the four sides of the tray. The bottom H of the receptacle is relatively thin and after merging into the side and end walls [2, l3 and M the latter preferably increase in thickness in the direction of the upper edges thereof. These side and end walls are sloped or inclined in an upward direction so as to facilitate the removal of the ice cubes from the tray. The end walls I3 and i4 terminate at their upper edges in outwardly extending flange portions I5 and [6 respectively which are preferably of increased thickness and serve the purpose of handles or hand grips which not only may be grasped to remove the tray from the refrigerator compartment but also may be grasped to facilitate flexing or twisting of the tray in removing or ejecting the cubes therefrom.

The pan shaped receptacle [0 is molded to provide a number of transverse grid or divider members I! which are integral with the bottom it as well as the side walls l2. In the present iiistance the tray is formed with seven grid or divider members I! which together with the end walls divide the receptacle into spaces for the production of eight ice cubes or blocks. It will be understood that the tray may be formed with Before explaining in detail the present invenw a smaller or larger number of divider strips for the purpose of producing the desired number of ice cubes. I prefer to utilize an injection molding process for producing in one piece the receptacle l and transverse grid or divider members I1. It will be noted that each of the divider members or strips I1 is generally wedge shaped in cross section. The lower edges lid of the divider strips are joined to the bottom H by curved fillets which in effect produce transverse stiffening ribs effective to reinforce the receptacle and enable the bottom II to be made quite thin so as to reduce the rate of freezing. Each of the divider strips or members l1 diminishes in thickness toward the upper edge llb thereof so as to have tapering side walls. By this construction the side walls of each ice cube space formed by two of the divider strips ll flare or taper upwardly thereby facilitating the ejection of the frozen ice cubes therefrom. It will be apparent, therefore, that by flaring the walls I2 as well as the walls 11 of each freezing space the ice cube may be forced outwardly through the top opening of this space very easily. As illustrated in Fig. 1, the ends of the divider strips I! are joined to the side walls i2 by curved fillets l8 which in effect form ribs which are continuations of the corresponding rib-like portions along the lower edges of the members I! and which in like manner reinforce the tray and assist in maintaining the shape thereof after continued use.

In the present embodiment of the invention the upper edges 12a of the side walls of the tray receptacle are formed with notches or depressed portions [9, a pair of these notches being provided centrally of the side wall portions of each freezing space. The notches l9 are of suitable depth and preferably arcuate in configuration, and these notches serve the two purposes of controlling the height of the water level in the tray when filled and of increasing somewhat the flexibility of the side walls of the tray so as to facilitate bending of the tray when it is desired to re= move the ice cubes therefrom in this manner. By providing the overflow openings or notches IS the water level in the tray after filling may be maintained at a level corresponding substantially to the bottoms of the notches, and hence when the water freezes and expands upwardly the frozen ice cubes or blocks will not project upwardly beyond the upper edges of the divider members l1 nor will the ice blocks be joined across the tops of these divider strips so as to interfere with the quick ejection of the ice cubes from the tray.

As previously stated, the receptacle l0 including the divider or grid members I! is formed in a single injection molding operation from polyethylene plastic or equivalent material. Polyethylene is particularly adapted for use in the fabrication of the present ice tray for the reason that this material has a wax-like surface which is non-wettable by water and, hence, inhibits the adherence of the ice thereto. Polyethylene is not only tough, flexible and substantially unbreakable, even under conditions of hard usage, but will also yield under tension in order to compensate for the expansion of ice upon freezing. After formation of the ice cubes in the tray the cubes may be readily loosened from the bottom and side walls of the freezing spaces upon grasping the flange portions I and I6 or the ends of the pan and torsionally twisting, flexing or bending the same. The cubes may also be removed individually from the freezing spaces by placing the fingers upon the upper edges of the freezing space and the thumbs against the bottom of the space and then applying pressure with the thumbs against the bottom of the freezing space so as to force the ice cube out of the pan. This method of ejecting the cubes individually from the pan is facilitated by reason of the thin flexible character of the bottom wall ll of the pan and the taper given to all four sides of the freezing space.

I prefer to form the bottom II of the pan or receptacle ill with a wall thickness as low as approximately .030 of an inch. Wall thicknesses ranging from approximately .030 to .040 of an inch are satisfactory for the bottom of the pan, it being understood that the wall thickness of the upright sides and end of the pan increase progressively and uniformly so as to have substantially greater thickness at the upper edges thereof. The wall thicknesses of the upper edges of the side and end walls of the pan may range from approximately .050 to .093 of an inch. This construction together with the rib-like fillets formed along the bottom and side edges of the divider strips I! afford sufficient form-sustaining rigidity to the tray regardless of the unusual thinness given to the bottom thereof. The divider members H may taper to a thickness at the upper edges thereof corresponding substantially to the thickness of the bottom ii. Although the thickness of the bottom I i of the tray receptacle preferably falls within approximately the foregoing range. it will be understood that a wall thickness from approximately .020 to .065 of an inch will give good results.

I claim:

1. A liquid freezing tray comprising a generally rectangular pan-shaped member formed with a bottom and surrounding upright outer side walls, a plurality of transverse divider strips integrally joined along their bottom and end edges to the bottom and to an opposed pair of said side walls, each strip diminishing in thickness from the lower edge to the upper edge thereof, the upper edges of said opposed outer side walls being formed with a plurality of notches.

2. A liquid freezing device comprising a pan shaped tray and grid members dividing the tray into a plurality of liquid freezing spaces, the upper edge of an outer side of said tray being formed with depressed portions for controlling the level of liquid in said spaces independently of one another when the tray is filled.

' 3. A liquid freezing device comprising a panshaped tray having a bottom and surrounding upright side walls, and grid means dividing the tray into a plurality of separate liquid freezing compartments, the upper edges of a pair of opposed outer side walls having notches for controlling the level of liquid in said compartments each independently of the others when the tray is filled.

JOHN H. ROETHEL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,820,221 Geyer Aug. 25, 1931 2,287,972 Carney June 30, 1942 2,433,211 Gits Dec. 23, 1947 2,452,846 Flynn Nov. 2, 1948

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