Ice-Making Machine

The present invention relates to an automatic ice maker comprising a tray, which has at least one automatically emptiable compartment for moulding a piece of ice, a storage chamber for receiving pieces of ice produced in the compartment and a sensor for detecting the presence of pieces of ice in the storage chamber.

Such an ice maker is known from U.S. Pat. No. 6,571,567 B2.

In the case of this known ice maker the sensor is formed by a motor-driven pivotable lever which enters from above into the storage chamber until further movement thereof is obstructed by pieces of ice disposed in the chamber. In order to make a decision whether pieces of ice shall be produced automatically the setting in which the pivotable lever comes into contact with the pieces of ice present in the storage container has to be detected and evaluated.

The use of movable parts makes this known ice maker susceptible to disturbance. Failure of the motor can lead to false detection of the filling state in the storage chamber so that no ice is produced although the quantity contained in the storage chamber is not sufficient or so that the automatic ice producing is continued even when the storage chamber is already full. The known sensor is also not in a position of detecting if a collecting container for the pieces of ice should happen to be absent. If this is the case the pieces of ice can pass to locations of the refrigerating appliance, which receives the ice maker, at which they are not desired.

The object of the present invention is to create an ice maker enabling detection, which can be realised in simple, reliable and economic manner, of pieces of ice in a storage chamber.

The object is fulfilled in that the sensor of the ice maker comprises a transmitter and a receiver for a detection beam which can come into interaction with the pieces of ice in the storage chamber.

The transmitter and the receiver are preferably arranged at opposite sides of the storage chamber. This allows recognition of the presence of ice on the basis of attenuation of the detection beam, which is attributable to absorption and/or diffusion of the beam at the pieces of ice. It would, in fact, also be possible to arrange transmitter and receiver adjacent to one another at a side of the storage chamber and a reflector for the detection beam at an opposite side of the storage chamber, but here the possibility of falsification of the detection result due to radiation scatter exists to increased extent.

The sensor is preferably an optical sensor. This can be realised economically. If the sensor uses light in the visible spectral range, the functional capability of a sensor is recognisable by a user without assistance.

Preferably moreover a sensor is provided which serves for detection of the presence of a removable storage container in the storage chamber. With the help of such a sensor it is possible to suppress automatic operation of the ice maker even if no ice is detected in the storage chamber, but if the storage container is absent and accordingly risk exists that finished pieces of ice removed from the tray pass to locations where they are not desired.

The storage container should advantageously be permeable to the detection beam so that transmitter and/or receiver can be arranged below an upper edge of the storage container placed in the storage chamber and thus be in a position of detecting pieces of ice before the filling state of the storage container exceeds the upper edge thereof.

The permeability can be achieved by use of a material for the storage container which is transparent to the detection beam, but it is also conceivable to form a window for passage of the detection beam in the storage container, wherein this window can easily be made so small that pieces of ice cannot fall through.

It is also advantageous if the detection beam runs in the ice maker at an inclination, because it is thereby possible to detect that the pieces of ice in the storage container exceed an envisaged maximum filling state which lies below the upper edge of the container even if, of transmitter and receiver, only one is arranged below the upper edge of the storage container. The detection beam therefore crosses the wall of the storage container only once and is only slightly attenuated thereat.

The sensor for detecting the presence of the storage container preferably comprises a detection body which is displaced from an equilibrium position to a deflected position by the storage container present in the storage chamber. Since the detection body adopts the equilibrium position insofar as it is not obstructed thereat by the storage container, the presence of the storage container is recognisable from the setting of the detection body.

In order to reliably bring the detection body into the equilibrium position in the case of presence of the storage container, it is preferably loaded by a spring in the latter position.

With particular preference the detection body interacts with the detection beam in respectively different manner in its equilibrium position and in the deflected position. This makes it possible, on the basis of the intensity of the detection radiator received by the transmitter, to recognise in which position the detection body is disposed and consequently whether the storage container is present or not.

Advantageously the interaction is so designed that the detection body in the equilibrium position attenuates the detection beam more strongly than in the equilibrium [sic] position. Since also ice present in the radiation path attenuates the detection beam, if the intensity of the detection beam received by the receiver is greater than a predetermined limit value it can be concluded therefrom that the storage container is present and that it is not filled up to the envisaged maximum, so that ice may be produced. If, conversely, the intensity detected by the receiver is smaller than the limit value, this can be due to non-presence of the storage container or due to presence of ice; both are a cause for interrupting ice production.

A particularly space saving and robust construction results if the detection body is hollow and at least in the displaced setting of the transmitter or the receiver engages in the detection body.

Further features and advantages of the invention are evident from the following description of examples of embodiment with reference to the accompanying figures, in which:

FIG. 1 shows an exploded illustration of an automatic ice maker according to a preferred embodiment of the invention;

FIG. 2 shows a perspective view of the ice maker according to FIG. 1 in assembled state with ice-maker tray in tilted setting;

FIG. 3 shows a front view of the ice maker of FIG. 1 or 2 in the direction of the pivot axis;

FIG. 4 shows the view of FIG. 3 with partly cut-away sensor housing;

FIG. 5 shows a view, which is analogous to FIG. 2, with ice-maker tray in upright setting;

FIG. 6 shows a view, which is analogous to FIG. 4, with the ice-maker tray in upright setting;

FIG. 7 shows a perspective view analogous to FIGS. 2 and 5 with the ice-maker tray in emptying setting;

FIG. 8 shows a view analogous to FIG. 4 or 6;

FIG. 9 shows a perspective exploded view from below of the ice-maker tray;

FIG. 10 shows a view of the ice maker from below;

FIG. 11 shows a section through the ice maker along the line XI-XI from FIG. 10, with detection body in deflected position;

FIG. 12 shows an enlarged detail of FIG. 11, partly in section along the line T-T of FIG. 11;

FIG. 13 shows a section through the ice maker along the line XI-XI of FIG. 10, with detection body in equilibrium position; and

FIG. 14 shows an enlarged detail of FIG. 13, partly in section along the line T-T of FIG. 13.

FIG. 1 shows an automatic ice cube maker according to the present invention in an exploded perspective view. It comprises a tray 1 in the form of a channel with a semi-cylindrical base, which is closed at its ends by respective transverse walls 2 and is divided by partition walls 3, which are arranged at uniform spacings, into a plurality of identically shaped compartments 4, here seven units, with a semi-cylindrical base. Whereas the partition walls 3 at the longitudinal wall 5 remote from the viewer adjoin flushly, the longitudinal wall 6 facing the viewer is prolonged above the upper edges of the partition walls 3. Whilst the partition walls 3 are exactly semicircular, the transverse walls 2 each have a sector 7, which goes out above the semicircular shape, in correspondence with the protrusion of the front longitudinal wall 6.

The tray 1 is shown in a tilted setting in which the upper edges of the segments 7 extend substantially horizontally, whilst those of the partition walls 3 are inclined towards the longitudinal wall 6.

The tray 1 can 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 hollow cylinder 11 is mounted at one of the transverse walls 2 of the tray 1; it serves for protected accommodation of a coiled power supply cable 12 serving for supply of current to a heating device 13, which is not visible in the figure, accommodated at the underside of the tray 1 (see FIG. 9). The tray 1 lies completely within a notional prolongation of the circumferential surface of the hollow cylinder 11, which at the same time represents the smallest possible cylinder into which the tray fits. An axial spigot 14, which protrudes from the transverse wall 2 facing the viewer, extends on the longitudinal centre axis of the hollow cylinder 11.

A frame moulded from plastics material is denoted by 15. It has an upwardly and downwardly open cavity 16 which is provided for mounting of the tray 1 therein. Bearing bushes 19, 20 for the pivotable mounting of the tray 1 are formed at the end walls 17, 18 of the cavity 16. A longitudinal wall of the cavity 16 is formed by a box 21, which is provided for reception of a drive motor 22 as well as various electronic components for control of operation of the ice maker. Mounted on the shaft of the drive motor 22 is a pinion 23 which can be seen better in each of FIGS. 3, 4, 6 and 8 than in FIG. 2. When the ice maker is in fully mounted state the pinion 23 finds space in a cavity 24 of the end wall 17. It forms there, together with a gearwheel 25, a speed step-down transmission.

The gearwheel 25 carries a pin 26 which protrudes in axial direction and which is provided for engaging in a vertical slot 27 of an oscillatory body 28. The oscillatory body 28 is guided to be horizontally displaceable with the help of pins 29 which protrude from the end wall 17 into the cavity 24 and which engage in a horizontal slot 30 of the oscillatory body. A toothing 31 formed at a lower edge of the oscillatory body 28 meshes with a gearwheel 32, which is provided for the purpose of being plugged onto the axial spigot 14 of the tray 1 to be secure against rotation relative thereto.

A cover plate 33 screw-connected to the open side of the end wall 17 closes the cavity 24. A fastening flange 34 with straps 35 protruding laterally beyond the end wall 17 serves for mounting the ice maker in a refrigerating appliance. A base plate 36 closes the box 21 at the bottom.

FIG. 2 shows, as seen from the side of the end wall 18 and the box 21, the ice maker with the tray 1 in tilted setting in perspective view. The upper edges of the sectors 7 at the transverse walls 2 of the tray 1 extend horizontally.

FIG. 3 shows a front view of the ice maker from the side of the end wall 17, wherein cover plate 33 and fastening flange 34 have been omitted in order to give free view into the cavity 24 of the end wall 17. 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 markings 37, 38 is disposed at the end wall 17 itself, or at the gearwheel 25 carrying the pin 26. When these markings 37, 38 are, as shown in the figure, aligned exactly with one another the pin 26 is 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 body 28 plugged onto the pin 26 as well as onto the stationary pin 29 is disposed at the righthand reversal point of its path.

Markings 39, 40, which are aligned with one another, at a flange 41 of the gearwheel 32 protruding beyond the tooth rim and at the end wall 17 indicate a correct orientation of the gearwheel 32 and as a consequence thereof also of the tray 1 engaging by its axial spigot 14 in a cut-out, which is T-shaped in cross-section, of the gearwheel 32. A pair, which is redundant per se, of markings 42, 43 at the toothing 31 of the pivot body 28 and at the gearwheel 32 shows the correct positioning of gearwheel 32 and oscillatory body 31 with respect to one another.

A sensor 44 for detecting the rotational setting of the gearwheel 32 is mounted near this. It co-operates with a rib 45, which protrudes in axial direction from the edge of the flange 41 on 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 of FIG. 3 the rib is covered for the greatest part by the sensor 44 and the oscillatory body 28. FIG. 4 differs from FIG. 3 in that the housing of the sensor 44 is shown in part cut away so that two light barriers 46, 47 bridging over the slot can be recognised in its interior. The rib 45 is disposed closely above the two light barriers 46, 47 so 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 tray 1 is disposed in the tilted setting and can stop the drive motor 22 in order to be able to keep the tray 1 in the tilted setting and fill it.

After a predetermined water quantity has been admetered to the tray 1 under the control of the control circuit the drive motor 22 is set in operation by the control unit in order to bring the tray 1 into the upright setting in which the water quantities in the compartments 4 of the tray 1 are cleanly separated from one another. This setting is shown in FIG. 5 in a perspective view corresponding with FIG. 2 and in FIG. 6 in a front view corresponding with FIG. 4. The gearwheel 25 is further rotated in clockwise sense relative to the setting of FIG. 4, although the same setting of the tray 1 can also be reached by rotation of the gearwheel 25 in counter-clockwise sense. Attainment of the upright setting is recognised when the rib 45 begins to block the lower light barrier 47.

The tray 1 remains in the upright setting for such a length of time until the water in the compartments 4 is 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 tray 1 and 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 motor 22 is set back into operation in order to rotate the gearwheel 25 into the setting shown in FIG. 8, with the pin 26 in the 9 o'clock position. The control circuit recognises that this position is reached when the two light barriers 46, 47 are again open. The rib 45 is now able to be clearly seen in the figure for a major part of its length.

In this setting the compartments 4 of the tray 1 are open downwardly so that the pieces of ice contained therein can fall into a storage chamber disposed underneath the frame 15.

The storage chamber can be bounded by a housing part, which is not illustrated in the figures, of the ice maker; in the simplest and preferred case, the storage chamber is merely a free space below the installation position of the frame 15 in a refrigerating appliance. Such a free space can, if the ice maker is not in operation, also be used for storage of stock, which is to be cooled, different from pieces of ice.

In order to facilitate release of the pieces of ice from the compartments 4, the already mentioned electric heating device 13 is provided. As can be recognised in FIG. 9, this heating device 13 is an electric heating rod which is bent into a loop and which extends in close contact with the tray 1 through between heat exchange ribs 49 protruding from the underside thereof and is in part received in a groove 48 formed at the underside of the tray 1.

The pieces of ice in the compartments 4 are thawed at the surface by brief heating of the tray 1 with the help of the heating device 13. The water layer thus produced between the tray 1 and 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 compartments 4 as a segment of a cylinder the pieces of ice easily slide out of the compartments 4 and drop into a collecting container 5 arranged in the storage chamber below the frame 15.

After emptying of the compartments 4 the drive motor is set back into operation and the gearwheel 25 further rotated in clockwise sense until it again reaches the setting shown in FIGS. 2 to 4 and a new operating cycle of the ice maker begins.

The collecting container 50 formed from glass-clear plastics material has, as shown in FIG. 7, substantially the form of a block, the open upper side of which extends under the entire length of the frame 15 with the exception of the hollow end wall 17 thereof. This end wall 17 has a downwardly directed projection 15 which reaches to below the upper edge of the storage container 50. A detection body 52, which in FIG. 7 is covered by the box 21 of the frame 15, is suspended at this projection 51 to be pivotable about a vertical axis 53. The detection body 52 is covered, in the perspective view of FIG. 8, for the greatest part by the outer surface, which faces the storage container 50, of the projection 51. Parts of the detection body 52 are to be seen merely through two windows 54, 55 of the outer wall. A helical spring 56 is coiled around the axis 53 of the detection body 52 and has free ends engaging at the outer wall of the projection 51. The spring 56 holds the detection body 52 pressed against the side wall of the storage container 50.

The detection body 52 is part of a multi-purpose sensor, the construction and function of which is clearer on the basis of FIGS. 10 to 14.

FIG. 10 shows a view of the frame 15 and the tray 1 suspended therein from below, wherein the tray is disposed in a setting corresponding with FIG. 5. A line XI-XI drawn obliquely over the box 21 of the frame 15 indicates the position of the section planes of FIGS. 11 and 13.

The motor 22 and parts of the transmission for driving the pivot movement of the tray 1 can be seen in the section of FIG. 11. Disposed below the transmission are a projection 51 with a side wall 17 of the detection body 52 and, partly surrounded by this, a light-emitting diode 52 emitting in the infrared or visible range.

The detection body 52 is pressed by the side wall, which bears thereagainst, of the storage container 50 against the force of the spring 56 into a deflected position in which it enters for the major part into the hollow side wall 17. In this position, as can be seen more clearly in the detail enlargement—which is partly sectioned along the plane T-T of FIG. 11—in FIG. 12, a window 58 of the detection body 52 lies on a straight line between the light-emitting diode 57 and an element 59, such as, for example, a photodiode, sensitive to the light of the light-emitting diode 57, the element 59 being accommodated in the box 21 at a side opposite the wall 17 and being oriented through a window 60 in an inclined wall at the underside of the box 21 onto the light-emitting diode 57. Thus, light from the light-emitting diode 57 can reach the photodiode 59 on a beam path 61 shown in FIG. 11 as a dot-dashed line.

The ice maker operates only when the light intensity received by the photodiode 59 exceeds a predetermined threshold. If a piece of ice is disposed on the beam path 61 between the light-emitting diode 57 and the photodiode 59 in the storage container 50 the light is scattered to such an extent that the threshold is fallen below at the diode 59. Further production of ice is thus inhibited when the filling state in the storage container 50 reaches up to the beam path 61. Since this beam path 61 runs, on a part of its length, under the upper edge of the storage container 50 the ice making is reliably stopped before the storage container 50 can overflow.

FIG. 13 shows a section, which is analogous to FIG. 11, through the frame 15, wherein, however, here the storage container 50 is removed. In this case the detection body 52 can yield to the pressure of the spring 56 and travels out of its equilibrium setting which is shown in FIG. 13 and, enlarged, in FIG. 14.

In this equilibrium setting the window 58 no longer lies in the beam path 61, so that the detection body 52 blocks the light beam. Therefore, if the storage container 50 is not present, an insufficient light intensity arrives at the photodiode 59 and the ice making is similarly stopped.

Ice-Making Machine

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CPC

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