Ice maker

Abstract

In an ice maker with a tray having at least one water-receiving cavity, a wall of the cavity contains a phase change material. If an ice maker of this kind is pre-cooled, so that the phase change material is solid, a great deal of heat can be removed from water poured into the cavities in a short time by the heat causing the phase change material to melt.

Claims

1. An ice maker, comprising: a tray having at least one cavity formed therein for receiving water, said tray having a wall defining said cavity and said wall containing a phase change material, said tray having a pivot axis around which said tray is pivoted; a further tray containing a phase change material, said further tray having a second pivot axis around which said further tray is pivoted; and a rack having a freezing position and an empty standby position, said empty standby position for carrying out a phase change of said phase change material, said tray and said further tray being supported in said rack and movable between said freezing position and said standby position, in each case, one of said trays is in said freezing position and said other tray is in said standby position, said pivot axis and said second pivot axis being moved during movement of said tray and said further tray between said positions.

2. The ice maker according to claim 1, wherein said phase change material is embedded in a matrix material of said wall.

3. The ice maker according to claim 1, wherein said wall has a hollow body which contains said phase change material.

4. The ice maker according to claim 1, wherein said tray and said further tray can be moved between the freezing position and the standby position by pivoting about a horizontal axis.

5. The ice maker according to claim 1, wherein said tray and said further tray at least partly overlap.

6. The ice maker according to claim 1, wherein: said further tray has a further cavity formed therein; and said tray and said further tray cannot hold water when in said standby position.

7. The ice maker according to claim 1, wherein said rack has an ejection opening formed therein for ice cubes.

8. The ice maker according to claim 7, wherein said tray in the freezing position can be pivoted into an ejection position about an axis and can be twisted in the ejection position.

9. The ice maker according to claim 8, wherein said tray in the freezing position is disposed below said further tray in the standby position.

10. The ice maker according to claim 9, wherein said axis about which said tray can be pivoted into the ejection position can also be said axis about which said tray can be twisted.

11. The ice maker according to claim 7, wherein said tray in the freezing position is disposed above said further tray in the standby position.

12. The ice maker according to claim 11, wherein said tray in the freezing position can be moved into an ejection position below said further tray.

13. A refrigeration appliance, comprising: an ice maker unit containing a tray having at least one cavity formed therein for receiving water, said tray having a wall defining said cavity and said wall containing a phase change material, said tray having a pivot axis around which said tray is pivoted; a further tray, said further tray having a second pivot axis around which said further tray is pivoted; and a rack having a freezing position in which said pivot axis and said second pivot axis are in a first location and an empty standby position in which said pivot axis and said second pivot axis are disposed in a second location, said empty standby position for carrying out a phase change of said phase change material, said tray and said further tray being supported in said rack and movable between said freezing position and said standby position, in each case, one of said trays is in said freezing position and said other tray is in said standby position.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(1) In the Figures:

(2) FIG. 1 shows a partly sectional, partly perspective view of an ice maker tray according to a first embodiment of the invention;

(3) FIG. 2 shows a section through an ice maker tray according to a second embodiment of the invention;

(4) FIG. 3 shows a section through an ice maker tray according to a third embodiment;

(5) FIG. 4 shows a schematic cross-section through an automatic ice maker with two trays; and

(6) FIG. 5 shows a section, analogous to FIG. 4, through an ice maker with two trays according to a further embodiment of the invention.

DESCRIPTION OF THE INVENTION

(7) FIG. 1 shows a sectional perspective view of an ice maker tray 1 according to a first embodiment of the invention. The tray 1 is an assembly of an inner shell 2, which is divided into two rows of cavities 3 which can be filled with water, and an undivided outer shell 4. The shells 2, 4 are connected in a sealed manner along their edges, e.g. fused or adhered, in order to form a hollow space 5, which extends between side walls 6, 7 and bases 8, 9 of the shells 2, 4 continuously over the entire length and width of the shells 2, 4. It is also conceivable to manufacture the two shells 2, 4 in one continuous piece, in particular by blow molding. The hollow space 5 is filled with a phase change material 33, typically a paraffin.

(8) The tray 1 can be freely placed in a freezer compartment of a domestic refrigeration appliance and thus can be used individually as a non-automatic ice maker; preferably it is a component of an automatic ice maker, the configuration and functionality of which will be explained in more detail with reference to FIGS. 4 and 5.

(9) A plurality of projections are formed on the end faces of the tray 1. Both end faces have a central cylindrical peg 10, which is provided to engage with a bearing of the automatic ice maker and define a pivot axis 31 of the tray 1; the end face 12 shown in FIG. 1 also supports an abutment projection 11, which is provided to block a further rotation of the end face 12 of the tray shown in the Figure after pivoting the tray 1 into an ejection position, in which the openings of the cavities 3 face downward, so that, when a motor engaging on the opposing end face rotates further, the tray 1 is intrinsically twisted and the ice cubes located inside are released.

(10) FIG. 2 shows, in a section transversely relative to the pivot axis 31, a tray 1 according to a second embodiment of the invention. The walls of the cavities 3 are here not formed by interlocking inner and outer shells as in FIG. 1, but rather they each comprise a shell 13, in which the cavities 3 are hollowed out, and hollow bodies 14 fastened to the outer sides of the shell 13 and filled with phase change material 33.

(11) The hollow bodies 14 can be flexible, elastically deformable hoses, which in each case extend transversely relative to the section plane over the entire length of the tray 1 and are able to adjust themselves to the available installation space, in particular in a gap 15 between the two rows of cavities 3, as long as the phase change material 33 contained therein is warm enough to be resiliently deformable.

(12) According to one development, at least those surface regions 34 of the hollow body 14 are embodied rigidly, which are provided to come into contact with the shell 13, while other surface regions can be flexible in order to permit a thermal expansion of the phase change material 33, and the hollow bodies are removably fastened to the shell 13. When the cooling capacity of the hollow bodies 14 assembled on the shell 13 is exhausted after one or more ice production cycles, these can be removed in order to be cooled down again at another location in the refrigeration appliance, and be replaced by fresh hollow bodies 14.

(13) FIG. 3 shows a cross-section through a tray 1 according to a third embodiment of the invention. Here, the tray 1 is injection molded in one piece from a mixture of a phase change material such as a paraffin with a matrix of polymer material. The mixing ratio of phase change material and polymer material is selected such that the tray is also solid above the melting point of the phase change material. Due to the homogeneous mixing, the liquid phase of the phase change material cannot be directly observed; the fact that a phase change takes place inside the tray 1 only indirectly shows that the thermal capacity of the tray 1 is strongly temperature-dependent and passes through a maximum in the surroundings of the melting temperature of the phase change material.

(14) According to one variant, the material of the tray 1 is not homogeneous, but rather the phase change material is present in the form of small bubbles embedded in the matrix. A tray of this kind can be realized by injection molding an emulsion of matrix and phase change material.

(15) It is also conceivable to manufacture the tray in FIG. 3 by first producing a granulate made of hollow plastic beads filled with the phase change material, mixing the granulate below the matrix and forming the resulting mixture into the tray 1.

(16) In order for the granulate to pass through an injection nozzle without being destroyed, its graining must of course be considerably finer than the wall thickness of the tray 1.

(17) The FIGS. 4 and 5 each show a schematic view of the configuration of an automatic ice maker with two trays 1, 1, in which in each case the tray may be according to any of the embodiments described above.

(18) The ice maker in FIG. 4 comprises a shelf or rack 16, of which a section of two longitudinal walls 17 are shown in the Figure. A window 19 is hollowed out in an end wall 18 of the shelf 16 in order to supply the interior of the shelf 16 with cold air, driven by a fan installed in the shelf 16 or a fan of the refrigeration appliance, in which the ice maker is accommodated.

(19) The two trays 1, 1 are located in said interior.

(20) The trays 1, 1 are each held by two arms 20, 20 engaging in a pivotable manner about the axes 31 or 31 on their end faces, which arms 20, 20 for their part can be pivoted about axes 21, 21 fixed to the end walls 18 of the shelf 16. The tray 1 is located in a freezing position, below a fresh water outlet 22, via which the cavities of the tray 1 can be filled with liquid water. The cold air flow entering through the window 19 covers the surface of the water in the cavities of the tray 1, so that it freezes quickly, supported by a phase change of the phase change material in the walls of the tray 1. If the cold air flow spreads along the base of the tray 1, this is also effectively cooled. The tray 1 is unable to receive any water in the standby position shown, tilted above the tray 1 against the left longitudinal wall 17, but the phase change material contained therein also freezes in the standby position.

(21) Both trays 1, 1 support the abutment projection 11, 11 explained with reference to FIG. 1 on their end face 12 or 12 facing toward the observer. On the opposing end face, a gear 23, 23 is non-rotatably connected to the tray 1 or 1. In the freezing position, the gear 23 meshes with a gear 24, which can be driven by an electric motor concealed on the other side of the end wall 18, in order to pivot the tray 1, after the water therein has frozen, about the pivot axis 31 running through the peg 10 into an ejection position, in which the cavities are facing toward an ejection opening 25 on the underside of the shelf 16 and the abutment projection 11 comes up against an end stop of the end wall of the shelf 16 (not visible in FIG. 1). The gear 24 being driven further after reaching this ejection position means that the tray 1 is intrinsically twisted, the ice cubes are released from the cavities and fall into a container (not shown) below the ejection opening 25.

(22) When this has happened, the shell 1 is pivoted about the pivot axis 31 back into the freezing position shown in FIG. 4 and then moved in mirror image to the standby position of the tray 1 shown in FIG. 4 by pivoting the arms 20 about the axis 21 into a standby position.

(23) The phase change material is now completely frozen in the tray 1. The tray 1 being pivoted into the freezing position brings its gear 23 into engagement with the gear 24. The tray 1 is filled via the fresh water outlet 22, and the water quickly freezes in contact with the phase change material of the tray 1 and the circulating cold air, while at the same time the tray 1 in the standby position also cools down. The emptying of the cavities of the tray 1 is in turn driven by a rotation of the gear 24.

(24) A particularly space-saving configuration is shown by the embodiment in FIG. 5.

(25) Here, a sun gear 26 and a ring gear 27 are mounted rotatably about an axis 32 on an end wall 18 of the shelf 16, and planetary gears 28 non-rotatably connected to the trays 1, 1 mesh with the sun gear 26 and ring gear 27. The upper tray 1 is in the freezing position, in which it can be filled via the fresh water outlet 22 and a cold air flow spreading over the shelf 16 can cool water in the cavities of the tray 1. In order to enable an efficient cooling also of the other tray 1 in the standby position below the tray 1 with cavities turned downward, windows can be provided in longitudinal walls 17 or end walls 18 of the shelf 16, depending on the circulation direction of the cold air.

(26) After the water in tray 1 has frozen, the sun gear 26 and ring gear 27 are co-rotated by 180, so that the trays 1, 1 change places. While the abutment projection 11 of the tray 1, now in the freezing position, can be moved in the radial direction, the abutment projection 11 of the tray 1, now in the ejection or standby position, engages into a groove concentric to the sun and ring gear 26, 27 on the end wall of the shelf 16 (not visible in the Figure) opposite the planetary gear train, which groove prevents a radial movement of the abutment projection 11. If one of the sun and ring gears is retained while the other is rotationally driven, the tray 1 is twisted and the ice cubes formed therein are ejected via the opening 25 on the base of the shelf 16.

(27) At the same time as the twisting of the tray 1, a pivoting movement of the tray 1 is driven about the axis running through the gear 23 and the peg 10. If the filling of the tray 1 only takes place afterwards, then this pivoting movement remains without any consequence. It can, however, also be used to connect the cavities 3 with one another temporarily, by the water in the filled cavities 3 flooding recesses 29 on the upper edges of the dividing walls 30 between them (see e.g. FIG. 1), ensuring a uniform filling of the cavities 3 as a result.

REFERENCE CHARACTERS

(28) 1 Tray 2 Shell 3 Cavity 5 Shell 6 Hollow space 7 Side wall 8 Side wall 9 Base 10 Base 11 Peg 12 Abutment projection 13 End face 13 Shell 14 Hollow body 15 Gap 16 Shelf 17 Longitudinal wall 18 End wall 19 Window 20 Arm 21 Axis 22 Fresh water outlet 23 Gear 24 Gear 25 Ejection opening 26 Sun gear 27 Ring gear 28 Planetary gear 29 Recess 30 Dividing wall 31 Pivot axis 32 Axis 33 Phase change material 34 Surface region 35 Surface region