US2433210A - Ice cube tray - Google Patents

Description

Dec. 23, 1947. J. A. Grrs 2,433,210

ICE CUBE TRAY Filed Feb. 2, 1945 2 Sheets-Sheet l Dec. 23, 19477 J. A. GlTs IcE cuE TRAY Filed Feb. 2, 1945 2 Sheets-Sheet 2 j A @V zh I Patented Dec. 23, 1947 ICE CUBE TRAY Joseph A. Gits, Chicago, Ill., asslgnorof one-half to Jules P. Gits, Chicago, Ill.

Application February 2, 1945,` Serial No. 575,798 14 claims. (ci. ia-108.5)

This application is a continuation in part of application Serial No. 418,753, filed November 12, 1941, which has become abandoned.

This invention relates to ice freezing trays adapted for use in refrigerators or the like for freezing a plurality of ice cubes.

Freezing trays used in refrigerators for producing ice cubes have been largely made of metal and of rubber, but the vshortage, of these materials has presented a real problem to the manufacturer. While metal is a good conductor of heat and permits freezing to be effected in va minimum period of time and rubber may be distorted to .eilect quick emptying ofthe cubes, both materials are of `a character that is known as frost forming and permit frost to build up rapidly along the sides of the trays and cause the same to be solidly frozen in the freezing chambery if left for a considerable period of time. other hand, these devices have been built as single trays which merely divide the interior into compartments by partitions, thereby exposing the outer and bottom sides only of the outer compartment's and the bottom side of the inner compartments. The freezing action was accordingly delayed and the removal of the ice cubes made difllcult. y

An object of the present invention is to provide an improved, simple and efficient form of structure for freezing trays, which may be advantageously made of a thermoplastic material capable of being molded in a single operation and providing maximum heat conducting surfaces for each compartment in which an ice cube is frozen.

A further object of the invention is to provide a freezing tray of improvedvstructure that may be made of a thermoplastic material which tends to retard frost formation upon the exposed outer' On the surfaces and to which the ice d-oes not necessarily tend to adhere so that the ice cubes may be readily dislodged or removed. Y

A still further object of the invention is to provide a freezing' tray of thermoplastic material that is somewhat resilient so that the tray may be twisted slightly to loosen the ice cubes Within the various compartments and thereby be removed witliout imparting heat to the outer surfaces before the cubes can be removed.

It is also an object of this invention to provide an improved, simple and efficient form of thermoplastic structure which may be twisted slightly to loosen the ice cubes `in the compartment and which is provided with a simple means A of limiting this twisting action whereby to pre-f vent permanent distortion ,of the tray.

Other objects andadvantages` of the invention-5,

will be apparent f-romthe following detallde scription when taken in connection with the accompanying drawings, which form a part hereof.

In the drawings:

Figure 1 is e. perspective view of a tray em-k bodying the invention; A Y

Fig. 2 is a side elevational view of this tray;

Fig. 3 is a longitudinal sectional view takenv floor or bottom of the freezing chamber which.v may be used in connection with the'tray to effect rapid freezing of the liquid in the tray;

Fig.` 9 is a transverse sectional view of the cooling chamber .but shown diagrammatically for illustrationpurposes only,l together with the tray in end elevation to.l illustratethe use of the bottom platel'shwn in Fig. 8; C

Fig. 10is amodifled formpf this bottom plate of the cooling chamber that may also be used in connection with'- the tray disclosed herein;

Fig. 11 is a'fragmentary perspective view illustrating the tray seated -upon this modified form-I Fig. 12 illustrates a further 4modification f wherein the tray is associated with a separate dish-like member embodying the principledisclosed in connection `with `the use of the bottom'l plates shown in Figs. 8 and 10, this dish-like member being adapted for .removal from the cooling chamber with the tray.

For the purposes of illustration, I have shown one form of embodiment of the invention. It is,

to be understood that this structure merely illustrates the invention herein disclosed so that those skilled in the art will be readily taught how to practice the invention.

The ice cube or freezing trayy I comprises a plurality of individual compartments 2 which may be arrangedin anyrcell-like pattern, for exf ample, as shown, intwo rows, and may be of any desirable shape, say, square, so as to produce true cubes of ice-if they are of the'same depth, or rectangular in cross section so as to produce small pieces of ice, which, while not true'cubes,

are considered.. i2usuch in the art and will be con;- K-

. 3 sidered as such for the purposesof this disclosure. Each compartment 2 is defined by four side walls I. 4. 5 and 8, and a bottom wall 1. The inner side walls may be designated l and the outer side walls may be designated 3. These side walls and the bottom merge into slightly rounded outside corners 8 which eil'ect rounded inside corners 9 at the bottom and the top and along the sides oi' each compartment. These rounded corners have been found to facilitate removal of the cubes and also to enhance the appearance ci' the tray.

'I'he upper portion of the side walls 3 to v6, inclusive, merge into what may be called an upper wall or ledge I that extends about all sides of the tray as well as between rows longitudinally of the tray and crosswise of the tray between adjacent compartments 2 of each row. 'I'he walls are designed to slant inwardly from the top to give an inward taper to each compartment and to further provide air spaces Il crosswise of the tray between adjacent compartments of each row and an air space l2 that runs longitudinally of the tray between the two rows and separates inner walls d, this being illustrated in Figs. 3 to 5, inclusive. The upper outer surface of wall 3 is given a slightly greater slant at i3 which merges with the upper face l0 to form in effect a substantial rim-like shoulder or ledge, as before mentioned, that extends along the outer top edges of the tray. The slanting inside walls d merge at M to form the central part or ledge separating the two rows of compartments. The slanting side walls 5 and t also merge at l5 to form the part of the upper wall lll or cross ledge between adjacent compartments of the same row, and, if the compartments of these rows are in alignment, as shown, the cross ledge extends from one to the other side of the tray. The general design efiects a very substantial structure across the top face of the tray which accomplishes certain advantages in the type of construction shown, as will be presently described.

The effect to be given by the arrangement described is that each compartment presents the appearance of an individual relatively small tray suspended from a top plate having holes cut therein that define the various compartments. I preferably extend one end of the tray at the upper wall or ledge l0 to form a forwardly curved handle portion i6, the same being of relatively substantial thickness at the juncture and tapering toward the outer edge so that a substantial mass of material isA provided along this front edge for a purpose also to be presently described.

I find that any suitable synthetic resin that is thermoplastic may be used and mention specifically ethyl and acetate cellulose because, within certain limits, they are slightly springy in character, will not soil when handled and may be made in different colors. Although the latter two features are not considered essential with respect to the present invention, it is desirable to use a plastic that will not be frost forming and to which ice will not freeze. Consequently, the material being resilient or springy in character, the tray may be twisted as shown in Fig. 6 and the ice cubes will be immediately freed from the compartments 2. I find that a plastic material is particularly desirable because it may be gripped without causing cold burns which occur in the case of metal trays.

Although thermoplastic material has certain desirable characteristics making the material particularly desirable for use in the construction of an ice cube tray and although difliculties heretofore experienced in its use and handling have been overcome, this material does not conduct heat as rapidly as metal. For this reason, it is found that the individual arrangement of compartments 2 and providing separate side walls for each compartment assures maximum heat conducting surfaces whereby the freezing period is reduced to a minimum. Also, it is found that slanting the side walls additionally provides not only air spaces between the walls of adjacent compartments but allows these air spaces to be increased in size without materially decreasing the capacity of the compartments. When the tray is placed in a cooling chamber, the heat is rapidly conducted from the walls so that the liquid in the compartments may be brought to a freezing temperature as rapidly as possible.

In Figs. 8 to 12, inclusive, various forms of bottom plates for the cooling chamber are illustrated, which may be used with the tray shown herein for the purpose of still further reducing thc freezing time if desired. In Fig. 8, bottom plate 25 is illustrated with a tapered rib 26 adapted to act not only as a guide for the tray when it is slid back and forth in cooling chamber 2l, but also as a heat conducting element in direct contact with the inside walls i of compartments 2 to facilitate a rapid cooling action. The tapering of air space l2 permits this rib 2B to be tapered, if so desired. Tapered ribs 28 may be provided transversely upon the bottom plate 29, shown in Fig. l0, for lying, 1f so desired, in the air spaces extending crosswise of the tray between the compartments. A tapered rib 30 disposed longitudinally upon plate 29 is also provided in this instance to lie in this air space i2 extending lengthwise of the tray between the two rows of compartments 2. The manner in which the tray will seat upon this type of bottomfplate is illustrated in Fig. 11. Transverse tapered ribs 28 are nested in transverse air spaces i i in substantially the same manner as the longitudinal rib 3U. These ribs are also tapered so as to engage side walls 5 and 6, as well as the walls Il. In this instance, it will be necessary to lift the tray up in order to clear these ribs before it may be removed from the cooling chamber. However, the cooling chamber may be of a depth permitting such lifting of the tray. Either bottom plate 25 or 29 may be provided with side ribs 35 shown in Figs. 8 and 9, which embrace the outer surfaces of walls 3 to increase the heat conducting action therealong. These ribs 35 may be higher than ribs 2S, 28 and 30, which can extend into spaces Il and I2 only to the height of the webs or partitions 33 and 34.

Figl2 illustrates a further embodiment of the bottom plates 25 and 29, illustrated in Figs. 8 and 10. In this instance, the tray is adapted to be first seated in a dish-like member or pan 3| before it is inserted in the cooling tray. Member 3l may have either the single longitudinal rib 28, or the combination of transverse ribs 28 and a longitudinal rib 30, as illustrated in Fig. l0. Member 3| may be provided in instances where the bottom plate of the cooling chamber is not furnished with these tapered ribs and it is desired to secure the reduced cooling period afforded by the use fo such ribs in direct contact with the walls of compartments 2.

The structure herein provided also permits the provision of openings or air passages 32 at the juncture of adjoining pairs of compartments so that it is possible to assure a relatively uniform thickness of wall for each compartment and eliminate thereby any uneven l freezing action where the conduction of heatV may not be as rapid. As previously mentioned, the tray may be twisted to dislodge the ice cubes from the compartments, as shown in Fig. 6. This may be accomplished because plastic material is somewhat resilient in character and is susceptible to deflection, but I yhave found that plastic material may bepermanentlyl distorted when twisted in this, manner. The individual construction of the compartments permits a certain resiliency in the structure shown but to preventy this structure from beingV permanently distorted when the tray is flexed,

' tion with the top face or rim-like shoulder I3 that extends about the tray to provide a very substantial structure and aid in conducting heat from compartments 2. They will also prevent a twisting action that is apt to cause distortion. I find that these webs or partitions 33 and 34 novelly cooperate in the general design herein disclosed to provide a very efficient type of tray made of plastic material. They permit the individual construction of each compartment with separate wallsfor each compartment and stillprevent excessive flexing that would otherwise result Iin permanent set or breakage of the tray. They also provide a substantially solid top portion from which the walls of each compartment extend so that the tray is made sufficiently rigid to retain its shape even though subjected to abuse and rough handling that is apt to occur in the normal use of anice cube tray. Ledges I0, I4 and I5 function to transmit thev torsional twist throughthe entire body ofthe tray. As stated, connecting webs v33 and 34 tend to limit this torsional twist transmitted by the ledges, and further, by this limiting action they distribute the torsional twist to flex the side walls 3, 4, 5 and 6 individually, and, of course, the bottom wall 1 by the flexing of these sidewalls. In otherl words. the webs 33 and 34 serve a dual function, and therefore, novelly cause the side and bottom walls of each compartment 2 to flex,thereby releasing, or aiding in releasing, the ice cubes.

Thermoplasticvmaterial permits the handling of the tray with cubesfrozen therein without the freezing of thehands tothe outside surfaces of thetray walls. Moreover, the tray may be handledfwith greater facility. It will not scratch or chip porcelain bodies and highly finished surfaces when dropped thereon. If dropped, the tray willnot break nor become dented and will not cut a linoleum covered surface as in the case of metal.' Moreover, these desirable features are augmented in the present case because the construction permits ready gripping to free the cubes :A V'further advantage resides in the fact that nique constructionmay be made in a single 'duction of a perfect article wherein the strains,

if, ,a l 1y, are uniformly distributed. Fig. '7 illusoperation, preferably by'inj'ection molding under l 'relatively high pressures which assures the protratesfsomewhat diagrammatically a die 40 which may be used. This die 40 comprises two separable parts 4I and 42 between which a cavity 43 is provided, Thiscavity 43 is of a shape corresponding to that of the tray and communicates with the sprue 44 by any suitable number of passages 45. The finished product may be formed in this manner by a single operation which reduces the cost of manufacture by an appreciable margin over metal formed trays requiring a -number of operations, both in the forming and in the assembling.

From the foregoing description it will be apparent that a simple, practical and improved form of ice cube or freezing tray is provided that embodies and provides for features of advantage ndt heretofore obtained. The u-se of thermoplastic material permits making a structure which is highly desirable, while the structure itself accomplishes advantages as to the time requiredto freeze and thereafter as to the ease of removal of the cubes. The ice cubes do not tend to adhere to the thermoplastic material while the resilient characteristic of this thermoplastic material can be used in connection with the design of the construction to free the ice cubes quickly without permitting the use of excessive twisting that will crack or permanently destroy the tray.

Without further elaboration, the foregoing will so fully explain the gist of my invention that others may, by applying current knowledge, readily adapt the same for use under varying conditions of service, without eliminating certain features, which may properly be said to constitute the essential items of novelty involved, which items are intended to be dened and secure-dto me bythe following claims.

I claim:

1. An -ice freezing tray comprising a molded body of thermoplastic material characterized by a resiliency permitting flexing to free the ice, separately formed compartments having their walls integrally formed and integrally united along their top edges to the walls of adjacent compartments, the walls between adjacent compartments below their top edges being separated by air spaces to provide for individually exposed heat conductiong surfaces for each compartment, said molded body being twistable to iiex said walls, and integrally formed transverse ribs bridging said air spaces and connecting the walls of adjacent compartments tolimit the* flexing of said walls when said molded body is twisted to free the bodies of ice in said compartments.

2. An ice freezing tray comprising a molded body of thermoplastic material characterized by va resiliency permitting flexing tofree the ice,

separately formed compartments having their walls integrally formed and integrally united along their top edges to the walls of adjacent cornpartments, the walls between'adjacent compartments below their top edges being separated by air spaces to provide for individually exposed heat conducting surfaces for each compartment, said molded body being twistable to iiex said walls to free the bodies of ice in said compartments, a row of segments ofsaid thermoplastic material disposed in a plane parallel tothe longitudinal center line of said tray and connecting'opposing walls of adjoining compartments for a portion'of the depth of said compartments.

3. An icesfreezing tray comprising a body of thermoplastic material having a pluralityof compartments, each compartment having side walls and a bottomwall that are of continuousfformation with respect to each other, the side walls being united adjacent their top edges to the side walls of adjacent compartments, certain of the side walls tapering inwardly to provide tapered air spaces between the opposing side walls of adjacent compartments, and bracing means bridging said air spaces between the opposing side walls of adjacent compartments to interlock all of said compartments at said side walls as well as adjacent the top edges thereof.

4. An ice freezing tray comprising a body of thermoplastic material formed into a plurality of compartments, each compartment having individual walls, the side walls of adjoining compartments being joined together along their upper edges, said material and said walls beingexible to cause the walls temporarily to deform and thereafter to return to .their normal condition whereby to release the frozen mass in each compartment when said body is gripped at opposite ends and torsionally twisted, the material along the upper edges where said walls are joined transmitting said torsional twist through the entire body, and limiting ribs between walls of adjoining compartments restricting said torsional twist so as to distribute the same throughout the body to secure flexure of the individual walls of each compartment without a distortion of the material that will cause a permanent set or fracture of the material.

5. A freezing tray comprising a body of thermoplastic material formed into a plurality of compartments, the side walls oi adjoining compartments being joined together along one edge, said material and said walls being flexible to cause the walls temporarily to deform and thereafter to return to their normal condition whereby to release the frozen mass in each compartment when said body is gripped at opposite ends and torsionally twisted, the material where joining the side walls of adjoining compartments transmitting said torsional twist through the entire body, and limiting ribs between walls of adjoining compartments restricting said torsional twist so as to distribute the same throughout the body to secure flexure of the Walls of the compartments without distortion of the material that will cause a permanent set or fracture of the material.

6. An ice freezing tray comprising a body of thermoplastic material formed into a plurality of compartments, each compartment having individual walls including'side and bottom walls, the side walls oi.' adjoining compartments being joined together along their upper edges. said material and saidwalls being flexible to cause the walls temporarily to deform andl thereafter to return to their normal condition whereby to release the frozen mass in each compartment when said body is gripped at opposite ends and torsionally twisted, the material along the upper edges where said walls are joined transmitting said torsional twist through the entire body, and segments connecting certain of said walls of said compartments tending to distribute the torsional twist throughout the body to assure a flexing of the walls of said compartments without distortion of the material that will cause a permanent set or fracture of the material.

7. An ice freezing tray comprising a body of thermoplastic material characterized by a resiliency permitting flexing to free the ice, separately formed compartments having their walls integrally formed and integrally united along their top edges to the walls of adjacent compartments, the walls between adjacent compartments below said top edges being separated by air spaces to provide for individually exposed heat conducting surfaces for each compartment, said body being twistable to flex said walls suillciently to free the bodies of ice in said compartments. and means connecting certain of said walls of said compartments, said means limiting the twisting and tending thereby to prevent distortion or fracture of said body.

8. A non-frost forming and non-ice adhering freezing tray comprising individual cube-forming compartments arranged in parallel rows, said compartments having individual but integrally connected walls and having their upper edges common with one another, said walls being entirely of a resilient thermoplastic material, the opposing walls of adjacent compartments of each row being spaced from each other with air spaces therebetween, said tray Walls and said thermoplastic material being of such character as to effect substantially complete release of the frozen material individually from each compartment or from all of the compartments at one time by manually gripping the ends of the tray and torsionally twisting the tray to flex said Walls, and portionsof flexible thermoplastic material disposed on veach side of the longitudinal center line of the tray and bridging said air spaces for connecting certain of the Walls of adjacent compartments, said portions tending to transmit said .torsional twist of the tray when flexed manually without distortion of the material that will cause a permanent set or fracture of the material.

9. A non-frost forming and non-ice adhering freezing tray comprising individual cube-forming compartments having individual but integrally connected walls spaced from each other on all sides but having their upper edges common with one another, said walls being entirely of a resilient thermoplastic material and being self-sustaining when said compartments are filled with water, said tray walls and said thermoplastic material being of such character as to effect substantially complete release of the frozen material individually from each compartment or from all of the compartments at one time by manually gripping the ends of the tray and torsionally twisting the tray to flex said walls, and a row of segments of said thermoplastic material disposed in a plane parallel to the longitudinal axis of said tray and connecting opposing walls of adjoining compartments for a portion of the depth of said compartments.

10. A non-frost forming and non-ice adhering freezing tray comprising individual cube-forming compartments having individual but integrally connected walls spaced from each other on all sides but having their upper edges common with one another, said walls being entirely of a resilient thermoplastic material and self-sustaining when said compartments are filled with water, said tray walls and said thermoplastic material being of such character as to effect substantially complete release of the frozen material individually from each compartment or from all of the compartments at one time by manually gripping the ends of the tray and torsionally twisting the tray to flex said walls, and segments of said thermoplastic material disposed on each side of and substantially parallel to the longitudinal center line of said tray and connecting opposing walls of adjoining compartments for a portion of the depth of the compartments.

11. An ice freezing tray comprising a body of thermoplastic material characterized -by a resilassaaio iency permitting flexing to free the ice, separately formed compartments having their walls integrally formed and integrally united along .their top edges to the walls of adjacent compartments, the walls between adjacent compartments below their top edges being separated by. air spaces to provide for individually exposed heat conducting surfaces for each compartment, said body being twistable by a manual gripping of the tray at its ends to flex said walls to free the bodies ofvice in said compartments, and portions of thermoplastic material disposed on each side of the longitudinal center line of said tray and bridging said air spaces for connecting certain of the walls of adjoining compartments, said portions of thermoplastic material tending to transmit a torsional twist to ex said walls when said tray is manually 10 when said compartments are iilled with liquid, :the top portions of said compartments where said walls are joined cooperating to produce a formation that will transmit an endwise torsional twist of the tray through all of said walls to distort the normal shape cross sectionally of each compartment whereby to loosen frozen material in each compartment.

13. The freezing tray of claim 12 wherein the material is an ethyl cellulose composition.

14. The freezing trayvof claim 12 wherein the material is a cellulose acetate composition..

JOSEPH A. GITS.

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

UNITED STATES PATENTS Number` I Name Date 1,407,614 Wicks Feb. 21, 1922 1,803,734 Scherer May 5, 1931 1,868,070 Newman ....yJuly 19,1932 1,923,522 Whitehouse Aug. 22, 1933 2,035,679 Thompson Mar. 31. 1936 2,145,719 Geyer c Jan. 31, 1939 2,193,342 Price Mar. 12, 1940 2,323,486 Pizarro July 9, 1943 2,386,979 Rundell Oct. 16, 1945

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