In the case of an ice maker comprising a frame (15) and a tray (1), which is pivotable in the frame (15) about an axis and in which at least one compartment (4) is formed, a flexible line (12) connecting the tray (1) with the frame (15) extends in a curve about the pivot axis of the tray (1).

The present invention relates to an automatic ice maker comprising a frame and a tray, which is pivotable in the frame about an axis and in which is formed at least one compartment able to be filled with water in order to produce a piece of ice in a shape predetermined by the compartment.

An ice maker of this kind is known from, for example U.S. Pat. No. 6,571,567 B2.

In this conventional ice maker a motor subassembly is coupled to a pivot axis of the tray in order to pivot the tray from an upright setting in which water can freeze in the compartments of the tray to an emptying setting in which the openings of the compartments face downwardly so that the pieces of ice could drop out. However, in this connection it is problematic that the finished pieces of ice usually adhere quite firmly to the walls of their compartment so that their weight alone is nowhere near sufficient to allow them to drop out of the compartments. For the proposed release by twisting the tray, a powerful and correspondingly large and expensive motor is required.

It is known from U.S. Pat. No. 3,180,103 to release finished pieces of ice from the compartments of a tray in that the tray is electrically heated until the pieces of ice thaw at the surface and to then push them out of the compartments with the help of a motor-driven pusher. Such an ice maker needs a large amount of space because in order to collect the finished pieces of ice either a collecting container, into which the finished pieces of ice are pushed, has to be placed near the tray or sufficient free space has to be present near the tray so that the pieces of ice can fall through the free space into a collecting container arranged thereunder.

If it is attempted to facilitate release of the pieces of ice, in the case of the ice maker of U.S. Pat. No. 6,571,567 B2, by heating then the problem arises that a heating means mounted in stationary location can heat the tray only less effectively; much heat is lost without use and leads merely to increased power consumption of a refrigerating appliance in which the ice maker is used. Mounting of the heating means at the tray obliges a supply line which extends between the tray and the frame and the operating safety of which in the moist, cold environment in which the ice maker is used is difficult to guarantee.

The object of the invention is to create an ice maker which conjoins a compact construction with a high degree of operational safety.

The object is fulfilled in that a flexible line connecting the tray with the frame extends in a curve about the pivot axis of the tray. A pivot movement of the tray leads, in the case of such a line, to at most a small loading in bending of the connecting points of the line to the frame or to the tray; essentially, merely the angle by which the line extends around the pivot axis changes slightly and the mean spacing of the line from the pivot axis decreases with increasing angle and increases with decreasing angle. A deformation, which is constrained by the pivot movement of the tray, of the line is distributed very uniformly over the length thereof and therefore leads to only a slight stressing of the material of the line.

Preferably the pivot axis is defined by a shaft around which the line extends.

In order to prevent an excessive curvature, which would load material, of the line in the case of a large pivot deflection a hollow winding core is preferably mounted to surround the shaft, around which the connecting line extends at a radial spacing. If in the case of a very strong pivot deflection the connecting line nests tightly against the winding core the then tautly tensioned connecting line prevents further pivotation.

The winding core is preferably arranged eccentrically with respect to the pivot axis in order to substantially avoid contact between the line and winding core, which could lead to rubbing wear.

A drum surrounding the connecting line substantially serves for protection of the connecting line against damage by foreign bodies as well as protection of a user against possible voltage-conducting contacting with the connecting line.

The drum is preferably mounted at the tray so that it pivots therewith. This makes it possible to fasten the winding core to the drum, preferably by detenting.

In order to mechanically relieve a connection of the connecting line, which extends continuously from the tray to the frame, at the tray, an intermediate piece of the connecting line extending continuously from the tray to the frame is preferably clamped between the tray and an arm radially protruding from the winding core.

Such an arm can also serve as a shield preventing contact between a movable part of the line and a possibly sharp-edged connecting point of the line with the tray.

As a further relief measure a hollow profile for fixing the intermediate piece in radial direction is provided at the arm.

The greater the freedom of pivot movement of the tray the greater should also be the angle at which the line extends around the axis. This angle preferably amounts to at least half a turn.

The connecting line is usually an electrical line; however, the invention is also usable in the same way for other kinds of lines such as, for example, a water line for filling the compartment with fresh water.

The electric line can, as already explained above, serve as a supply line for the electric heating device mounted at the tray; however, it can also serve as a single line for derivation of a temperature signal from a sensor or the like arranged at the tray.

The tray is preferably pivotable from the upright setting, in which the upper edges of the partition walls between the compartments of the tray extend horizontally, not only into the already mentioned emptying setting, but also into a tilted setting in which the compartments (4) communicate over the upper edges of the partition walls (3).

The compartments of the ice maker tray are preferably arranged in at least one row and a wall extending above the upper edge of intermediate spaces separating the compartments of the row from one another is formed at a longitudinal side of each row of compartments and at least a part of the transverse sides thereof. This construction of the ice maker tray makes it possible for water filled into the compartments in the tilted setting to flood over the partition walls to a region adjoining the protruding wall so that exactly the same water state can be achieved in all compartments. When this tray is, for freezing, pivoted into the upright setting in which the partition walls extend substantially horizontally and are no longer flooded over, pieces of ice cleanly separated from one another and with exactly the same size can be produced.

The tray is coupled to a motor for driving the pivot motion preferably by way of an eccentric mechanism. This converts a rotational movement of the motor in the same sense into an oscillating pivot motion of the tray of an amplitude predetermined by the construction of the eccentric mechanism. A directional control of the motor is thereby redundant and over-stretching or excess compression of the line can thereby be reliably excluded.

The eccentric mechanism preferably comprises a linearly displaceable oscillatory body carrying a rack meshing with a gearwheel connected with the tray. Any desired pivot stroke of the tray can be easily constructed by such an arrangement.

An eccentric element is preferably in engagement with a rail which extends at the oscillatory body transversely to the direction of movement thereof in order to convert the circulatory motion of the eccentric element into a reciprocating motion of the oscillatory body.

In order to facilitate removal of the finished pieces of ice from the mould the compartments preferably have the shape of a segment of a body of rotation. A piece of ice can be removed particularly simply from these compartments in that it slides in circumferential direction of the body of rotation without, as in the case of a conventional block-shaped piece of ice under consideration from, for example, U.S. Pat. No. 6,571,567 B2, forming, during removal from the mould, between the base of the compartment and the ice body a cavity which prevents removal from the mould as long as there is no equalisation of an underpressure prevailing in the cavity.

FIG. 1shows an automatic ice cube maker according to the present invention in an exploded perspective view. It comprises a tray1in the form of a channel, which is closed at its ends by respective transverse walls2and is divided by partition walls3, which are arranged at uniform spacings, into a plurality of identically shaped compartments4, here seven units, with a semi-cylindrical base. Whereas the partition walls3at the longitudinal wall5remote from the viewer adjoin flushly, the longitudinal wall6facing the viewer is prolonged above the upper edges of the partition walls3. Whilst the partition walls3are exactly semicircular, the transverse walls2each have a sector7, which goes out above the semicircular shape, in correspondence with the protrusion of the front longitudinal wall6.

The tray1is shown in a tilted setting in which the upper edges of the segments7extend substantially horizontally, whilst those of the partition walls3are inclined towards the longitudinal wall6.

The tray1can be a plastics material moulded part, but preferably, due to the good capability of thermal conductance, it is constructed as a cast part of aluminium.

A cable drum11is mounted at one of the transverse walls2of the tray1; it serves for protected accommodation of a coiled power supply cable12serving for supply of current to a heating device13, which is not visible in the figure, accommodated at the underside of the tray1(seeFIG. 9). The tray1lies completely within a imaginary hollow cylinder defined by the circumferential surface of the cable drum11, which at the same time represents the smallest possible cylinder into which the tray1fits. An axial spigot14, which protrudes from the transverse wall2facing the viewer, extends on the longitudinal centre axis of the cable drum11. A corresponding axial spigot extending from the second transverse wall through the cable drum11is not visible in the figure. A winding core50made of plastics material is provided in order to be mounted, curled around by the supply cable12, in the cable drum11.

A frame moulded from plastics material is denoted by15. It has an upwardly and downwardly open cavity16which is provided for mounting of the tray1therein. Bearing bushes19,20for the pivotable mounting of the tray1are formed at the end walls17,18of the cavity16. A longitudinal wall of the cavity16is formed by a box21, which is provided for reception of a drive motor22as well as various electronic components for control of operation of the ice maker. Mounted on the shaft of the drive motor22is a pinion23which can be seen better in each ofFIGS. 3,4,6and8than inFIG. 2. When the ice maker is in fully mounted state the pinion23finds space in a cavity24of the end wall17. It forms there, together with a gearwheel25, a speed step-down transmission.

The gearwheel25carries a pin26which protrudes in axial direction and which is provided for engaging in a vertical slot27of an oscillatory body28. The oscillatory body28is guided to be horizontally displaceable with the help of pins29which protrude from the end wall17into the cavity24and which engage in a horizontal slot30of the oscillatory body. A toothing31formed at a lower edge of the oscillatory body28meshes with a gearwheel32, which is provided for the purpose of being plugged onto the axial spigot14of the tray1to be secure against rotation relative thereto.

A cover plate33screw-connected to the open side of the end wall17closes the cavity24. A fastening flange34with straps35protruding laterally beyond the end wall17serves for mounting the ice maker in a refrigerating appliance. A base plate36closes the box21at the bottom.

FIG. 2shows, as seen from the side of the end wall18and the box21, the ice maker with the tray1in tilted setting in perspective view. The upper edges of the sectors7at the transverse walls2of the tray1extend horizontally.

FIG. 3shows a front view of the ice maker from the side of the end wall17, wherein cover plate33and fastening flange34have been omitted in order to give free view into the cavity24of the end wall17. The configuration shown here is that in which the ice maker is mounted together. Various markings indicate a correct positioning of individual parts relative to one another. A first pair of markings37,38is disposed at the end wall17itself, or at the gearwheel25carrying the pin26. When these markings37,38are, as shown in the figure, aligned exactly with one another the pin26is disposed in a 3 o'clock setting, i.e. on the point, which lies furthest to the right in the perspective view of the figure, of its path which it can reach. The oscillatory body28plugged onto the pin26as well as the stationary pin29is disposed at the righthand reversal point of its path.

Markings39,40, which are aligned with one another, at a flange41of the gearwheel32protruding beyond the tooth rim and at the end wall17indicate a correct orientation of the gearwheel32and as a consequence thereof also of the tray1engaging by its axial spigot14in a cut-out, which is T-shaped in cross-section, of the gearwheel32. A pair, which is redundant per se, of markings42,43at the toothing31of the pivot body28and at the gearwheel32shows the correct positioning of gearwheel32and oscillatory body31with respect to one another.

A sensor44for detecting the rotational setting of the gearwheel32is mounted near this. It co-operates with a rib45, which protrudes in axial direction from the edge of the flange41on a part of the circumference thereof so that it can enter into a slot at the rear side of the sensor housing. In the tilted setting ofFIG. 3the rib is covered for the greatest part by the sensor44and the oscillatory body28.FIG. 4differs fromFIG. 3in that the housing of the sensor44is shown in part cut away so that two light barriers46,47bridging over the slot can be recognised in its interior. The rib45is disposed closely above the two light barriers46,47so that a control electronic system, which is not illustrated, can recognise, on the basis of the fact that the two light barriers are open, that the tray1is disposed in the tilted setting and can stop the drive motor22in order to be able to keep the tray1in the tilted setting and fill it.

After a predetermined water quantity has been admetered to the tray1under the control of the control circuit the drive motor22is set in operation by the control unit in order to bring the tray1into the upright setting in which the water quantities in the compartments4of the tray1are cleanly separated from one another. This setting is shown inFIG. 5in a perspective view corresponding withFIG. 2and inFIG. 6in a front view corresponding withFIG. 4. The gearwheel25is further rotated in clockwise sense relative to the setting ofFIG. 4, although the same setting of the tray1can also be reached by rotation of the gearwheel25in counter-clockwise sense. Attainment of the upright setting is recognised when the rib45begins to block the lower light barrier47.

The tray1remains in the upright setting for such a length of time until the water in the compartments4is frozen. The dwell time in the upright setting can be fixedly predetermined; alternatively, the control circuit can also be connected with a temperature sensor in order to be able to establish, on the basis of a measured temperature in the environment of the tray1and a characteristic curve stored in the control circuit, a respective time period sufficient in the case of the measured temperature for freezing the water.

After expiry of this time period the drive motor22is set back into operation in order to rotate the gearwheel25into the setting shown inFIG. 8, with the pin26in the 9 o'clock position. The control circuit recognises that this position is reached when the two light barriers46,47are again open. The rib45is now able to be clearly seen in the figure for a major part of its length.

In this setting the compartments4of the tray1are downwardly open so that the pieces of ice contained therein can drop out. The already mentioned electric heating device13is provided in order to facilitate release of the pieces of ice. As can be recognised inFIG. 9, this heating device13is an electric heating rod, which is bent into a loop and which extends in close contact with the tray1between heat exchange ribs49protruding at the underside thereof and is in part received in a groove48formed at the underside of the tray1.

Through brief heating of the tray1with the help of the heating device13the pieces of ice in the compartments4are thawed at the surface. The water layer thus produced between the tray1and the pieces of ice acts as a slide film on which the pieces of ice are movable with very low friction. By virtue of the cross-sectional shape of the compartments4in the form of a segment of a cylinder the pieces of ice easily slide out of the compartments4and drop into a collecting container (not illustrated) arranged below the ice maker.

After emptying of the compartments4, the drive motor is set back into operation and the gearwheel25further rotated in clockwise sense until it again reaches the setting shown inFIGS. 2 to 4and a new operating cycle of the ice maker begins.

The pivotation to and fro of the tray is accompanied by the fact that the supply cable12shown inFIG. 1is continuously deformed, the cable being fastened by one end at the level of the transverse wall2by two soldering eyes51to contact pins52of the heating device13and the other end of the cable being guided through a notch53in the wall of the box21receiving the electronic control system. The hollow-cylindrical winding core50shown in perspective view inFIG. 12is provided for protection of the cable12against rubbing wear. Approximately one-and-a-half coils of the supply cable12are, as can be seen inFIG. 10, looped in the cable drum11loosely around the winding core50.

The winding core50has an eccentric cylindrical bore which is plugged in rotationally fast manner on to an axial spigot14of the tray. The centre point of the winding core50is displaced from the pivot axis towards the end, which is clamped in the notch53, of the supply cable. When the tray is pivoted in clockwise sense in the perspective view ofFIG. 11, the coils of the cable12narrow and a tension force produced by the resilience of the cable12and acting in the direction of the end held in the notch53draws the cable coils downwardly to the right inFIG. 10towards the notch53(not shown here) so that the coils, although they become narrower, are spaced from the winding core50. In the case of rotation in counter-clockwise sense the resulting widening of the coils normally prevents contact between cable12and winding core50.

The deformable coils end at an arm54which radially protrudes from the winding core50and which presses the cable12, which dips away under it, against the transverse wall2of the tray disposed therebehind. As can be recognised inFIG. 12, a notch55which receives the cable12and fixes it in radial direction is formed at the underside of the arm54.

The contact pins of the heating device13are concealed under a second arm56radially protruding from the winding core50, so that the movable coils of the supply cable12cannot chafe thereagainst in operation. Resilient detent fingers57of the outer wall of the arm56serve for anchoring in a cut-out, which is of complementary shape, in the interior of the cable drum11.