Automatic icemaker including reversible mold cavities

[57] ABSTRACT

An icemaker comprising a rotatable member including oppositely facing receptacles having a common wall formed in part by a flexible and reversible wall portion defining a mold cavity in which a charge of water is frozen to form an ice piece. When the mold member is inverted and a charge of water introduced into the then upwardly facing receptacle, a previously formed ice piece is heat released from the mold cavity and the added charge of water causes the flexible wall portion to turn inside out to form a mold cavity for receiving the charge.

Claim, 6 Drawing Figures

3,449,921 6/1969 Connors...............................62/72 X

3,390,543 7/1968 Moreland et al.....................62/72 X

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PATENTED JUN -5 1973

3,736,767

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3,736,767

AUTOMATIC ICEMAKER INCLUDING REVERSIBLE MOLD CAVITIES

BACKGROUND OF THE INVENTION

In previously proposed icemakers comprising flexible and reversible mold cavities, such as the icemaker described in U.S. Pat. No. 2,697,918—Comstock, an ice piece formed in a cavity has been removed or discharged therefrom by inverting and mechanically turning the cavity inside out to discharge the ice piece thereby forming a reversed cavity for receiving a fresh charge of water. The mechanical mechanisms for accomplishing the discharge of the ice piece are quite complicated in operation and materially add to the cost of the icemaker.

It has also been proposed to provide automatic icemakers from which the ice pieces are released by the heat of a fresh charge of water which is thereafter frozen. The operating concept in most of these icemakers has been to provide rotatable molds comprising two or more sets of cavities with some of the walls of one set of cavities common to or in heat transfer relationship with some of the walls of the other set. Water added to one set is intended to free ice pieces from the other set as described in U.S. Pat. Nos. 2,407,058—Clum, 2,939,298—Bauerlein and 3,075,365—Hall. However, none of these icemakers have been considered satisfactory for household refrigerator use due to the fact that only portions of the total cavity wall structures are heated by the new charge of water. In other words, as shown in these patents, it is physically impossible to provide two oppositely facing mold cavities in which all of the wall areas of one cavity are in direct heat exchange with all of the wall surfaces of the other.

The present invention has as its principle object the provision of a rotatable icemaker of the heat release and gravity discharge type of a design such that a charge of water employed to heat release a previously formed ice piece does contact all of the cavity surface or walls from which an ice piece is to be discharged.

SUMMARY OF THE PRESENT INVENTION

In accordance with the present invention, there is provided an automatic icemaker comprising a rotatable member including oppositely facing receptacles having a common bottom wall. This common bottom wall includes at least one flexible and reversible wall portion forming a mold cavity in the bottom wall when either of the receptacles is in an upwardly facing position. Rotation of the mold member through 180° inverts the mold cavity so that an ice piece formed in the cavity can be gravitationally discharged. The introduction of a fresh charge of water into the then upwardly facing receptacle, which is designed to maintain that charge in heat exchange relationship with all of the flexible wall portion forming the mold cavity, heat releases the ice piece. The wall portion defining the cavity is sufficiently flexible so that as the ice piece is released, the weight of the fresh charge of water causes the wall portion to reverse and thereby form a new mold cavity for receiving the fresh charge of water.

BRIEF DESCRIPTION OF THE DRAWING

In the accompanying drawing:

FIG. 1 is a plan view of an automatic icemaker including a mold structure incorporating the present invention;

FIG. 2 is an elevational view, partly in section, of the icemaker of FIG. 1;

FIG. 3 is a transverse sectional view taken along line

3—3 of FIG. 1 showing a mold cavity with an ice piece formed therein;

FIG. 4 is a view similar to FIG. 3 illustrating the mold in an inverted position;

FIG. 5 is a view similar to FIGS. 3 and 4 showing the introduction of a fresh charge of water into the mold structure; and

FIG. 6 is a view similar to FIGS. 3,4 and 5 illustrating the manner in which the fresh charge of water heat releases an ice piece from an inverted cavity.

DESCRIPTION OF THE PREFERRED EMBODIMENT

With particular reference to FIGS. 1 and 2 of the drawing, the icemaker of the present invention comprises a rotatable mold member 1 formed of two oppositely facing receptacles 2 and 3 having a common bottom wall 4. The bottom wall includes one or more flexible and reversible wall portions 5 forming one or more mold cavities 6 which are preferably of hemispherical shape. In the illustrated embodiment of the invention, the common bottom wall comprises the bottom wall sections 7 and 8 of the respective receptacles 2 and 3 which include matching circular openings 9, and the flexible and reversible wall portions S are part of a molded and formed sheet 10 of silicone rubber or the like sandwiched between the bottom wall sections 7 and 8, the member 10 being formed to include the mold cavity forming wall portions 5 within the circular openings 9.

The icemaker also comprises a combination housing and mounting structure 12 on which the mold member is rotatably supported by means of a shaft 14, it being understood that the component 12 includes a drive motor, water supply means and control means for periodically rotating the mold member 1 through an angle of 180° and thereafter introducing a charge of water into the upwardly facing receptacle through a valve controlled water supply line 15 (FIG. 2).

The receptacles 2 and 3 are so shaped that a charge of water sufficient to fill the mold cavity or cavities will be so confined as to completely engage all of the cavity walls. The general shape of the receptacle to accomplish this purpose in a mold comprising a plurality of cavities is shown in FIG. 1.

Further details of the icemaker of the present invention will best be understood from a consideration of its operation through an ice making cycle, the sequence of operation being illustrated in FIGS. 3-6 of the drawing. FIG. 3 illustrates the position of the automatic icemaker mold at a point when ice pieces such as ice piece 17 has been formed in a mold cavity 6. The freezing period may be timed and after a predetermined period the mold member 1 is rotated 180° about its longitudinal axis by shaft 14 to the position shown in FIG. 4. A new charge of water 18 sufficient to approximately fill all of the mold cavities is then introduced into the upwardly facing receptacle 3 through inlet 15. This charge, as illustrated in FIG. 5, is confined by the walls of the receptacle 3 in direct heat exchange relationship with all of the flexible cavity wall portions 5. Preferably, this charge of water is relatively warm so as to quickly melt any ice bond between the inverted ice piece 17 and the mold cavity. The combined weight of the ice piece and

3,736.

the new water charge then causes a peeling stress around the periphery of the ice piece starting at the peripheral ice/cavity wall interface following the initial melting of the ice bond with the result that the cavity wall S turns inside out releasing the ice piece by peeling 5 from the cavity wall as shown in FIG. 6 of the drawing. During release of the ice piece, the cavity forming walls are completely reversed or turned inside out to form a new cavity for receiving all of the releasing charge of water. This charge is then frozen into ice and the cycle 10 is ready to be repeated.

Although silicone rubber is given as an example of a preferred material for forming the flexible wall portions 5, there are other materials which can be employed, the criterion being that the material should provide wall 15 portions 5 which are thin and flexible enough so as not to interfere with the reversing action but strong enough to withstand repeated reversal.

While a hemispherical configuration of the mold cavity is preferred, the invention is not limited thereto, the 20 only requirement being that the cavity shape be such that the peeling action referred to hereinbefore can take place and that the mold cavity can be turned inside out under the gravitational forces of the water and ice piece. While the receptacles 2 and 3 can be made 25 of metal they are preferably made of plastic since, for best operation, their heat capacity and thermal conductivity should be as low as possible, so that heat from the entering water charge will flow primarily through the cavity walls to the ice. 30

While there has been shown and described a specific ,767 embodiment of the present invention it will be understood that the invention is not limited thereto and it is intended by the appended claims to cover all such modifications as fall within the true spirit and scope of the invention.