Device for dispensing ice

Abstract

A device for dispensing ice, for example, into a glass and including a compression refrigerator unit in which the evaporator is formed by a container, part of the external surface of which forms part of the internal surface of one or more moulds for a liquid to be frozen, and including means for ejecting ice from the mould and into a chute through which it is dispensed into the glass. The evaporator is preferably an annular drum and the moulds are arranged around a circle centred upon its axis, the drum being indexable to bring each mould in turn into alignment with solenoid means for ejecting the ice from the mould. In one form the moulds are tapered and closed at a lower end by a natural rubber diaphragm and the solenoid means is mounted beneath the evaporator and energised to strike the diaphragm to eject the ice each time the evaporator indexes.

Description

This invention relates to a device for dispensing ice.

In most situations where ice is required in small quantities, such as in bars, public houses and clubs, it is normally produced in the form of ice cubes in a refrigerator and temporarily stored in heat insulated containers. During busy periods, therefore, when ice is in great demand, it is necessary frequently to replenish the temporary store. Further, since an ample supply of ice is not always considered a priority, ice is often not available when it is most needed.

It is an object of this invention to provide a means whereby a continuous supply of ice is available either to a customer or to bar staff.

According to this invention a device for dispensing ice for example into a glass comprises a refrigeration unit including a container forming an evaporator and having inlet and outlet openings for a fluid refrigerent, one or more moulds, at least a part of the internal surface of each mould being formed by a portion of an external surface of the container wall, means for supplying liquid to be frozen into the mould or moulds, and means for ejecting pieces of ice from the mould or moulds.

Preferably, the moulds are formed by tubular members passing through the container from an upper surface to a lower surface.

The device may include electrically operated means, for example a solenoid, for ejecting ice from the mould.

In one form, the device is mechanically operated and includes an operating lever and a cam or linkage means for effecting displacement of a plunger forming a closure for the mould thereby to eject ice from the mould.

Conveniently, a plurality of cams are mounted upon a shaft which is angularly displaceable through a predetermined angle by an operating lever and the cams are angularly spaced relative to one another, each cam being operatively associated with one or more plunger. Further, the lever is adapted to angularly displace the shaft only during a forward stroke so that successive operations of the lever effect intermittent displacement of the shaft and ejection of ice from one or more moulds.

A piston/cylinder arrangement is preferably associated with each cam and adapted so that during each forward stroke of the operating lever liquid is supplied to a mould or moulds from which ice was ejected during a previous forward stroke.

In order to dispense pieces of ice, the device may include a push rod connected to a linkage and driven during a latter part of each forward stroke by a protusion of a disc mounted upon the shaft.

In another form of device an evaporator according to the first aspect of the invention is in the form of an annular drum which is indexable to bring a mould or moulds into alignment with means for ejecting ice from the mould and a different mould or moulds into alignment with the means for supplying liquid to be frozen.

The drum is horizontally mounted for indexing relative to a plate or disc biased against a lower face of the drum to form a closure for the moulds which are formed around a circle centred on the axis of rotation of the drum.

In order to overcome problems of sticking and friction and for example, jamming of the drum due to excessive ice formation the upper surface of the plate or disc, the lower surface of the drum and/or the internal surface of the mould are coated with a P.T.F.E. such as Teflon (Registered Trade Mark).

It has, however, been found that the low friction property of P.T.F.E. deteriorates with time and is most marked when hard water is used, probably due to a deposit of calcium etc. entering the pores of the P.T.F.E. These deposits can be removed by cleaning, but this is troublesome.

In order to facilitate the removal of the ice from the mould the moulds are preferably substantially cylindrical and may be tapered. It has been found that, with a taper of about 10.degree., the deterioration of P.T.F.E. has no significant effect.

Since the lower opening of the moulds are closed by a plate or disc movable relative there-to, some liquid to be frozen will inevitably flow into the space between the plate or disc and the lower surface of the evaporator drum. To minimize this, a pipe carrying refrigerant from the evaporator is diverted beneath the plate or disc in a position wherein a mould or moulds are aligned with the means for supplying liquid to the mould or moulds. Thus, as liquid enters a mould a skin of ice speedily forms at the base of the mould and provides a seal for the remaining liquid.

The means for supplying liquid to a mould or moulds comprises a pump means arranged to dispense a measured quantity of liquid after indexing of the drum to a new position.

The plate or disc preferably is formed with an aperture or apertures in a position corresponding to an index position of the drum wherein, in use, the mould or moulds contains a block of ice. In this position ice is ejected downwardly from the mould or moulds, through the aperture or apertures and into a chute located beneath the apertures.

The problem of leakage between the lower surface of the annular drum and the plate or disc, described above, is completely avoided in a preferred form of device comprising a flexible diaphragm forming a closure for each mould, wherein the mould or moulds are tapered such that the cross-sectional area of the mould or moulds at the upper surface of the annular drum is larger than the cross-sectional area at the lower surface and wherein ice is ejected upwardly from the mould.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings of which:-

FIG. 1 is a schematic perspective view of one form of device for dispensing pieces of ice;

FIG. 2 shows the arrangement of an operating handle for the device shown in FIG. 1;

FIG. 3 shows a schematic cross-sectional view of the device pf FIG. 1;

FIG. 4 is a cross-sectional view of an evaporator for the device of FIG. 1;

FIG. 5 shows a circuit diagram for a solenoid means for ejecting ice from the mould;

FIG. 6 shows a schematically cross-sectional view of a preferred form of device for dispensing ice;

FIG. 7 shows a cross-sectional view of a preferred form of evaporator

Referring now to FIGS. 1 to 5, one form of ice dispensing device, part of which is shown in perspective in FIG. 1 includes an annular drum shaped evaporator 80 mounted for indexing about a vertical axis to bring each of sixteen moulds a to p in turn into alignment with a solenoid means 82 for ejecting ice downwardly from the mould into a chute 84 for dispensing ice into a glass (not shown).

Heat is extracted from water in the moulds to produce ice, by a refrigeration unit 15 including a self-contained, electrically operated compressor unit, a condenser and a capillary tube (not shown) connecting the compressor unit and the evaporator 80. The refrigeration unit operates as a compression system using Arkton or Freon 12 as a refrigerant. The capacity of the refrigeration unit is such as to permit a preferred maximum rate of operation once every 20 seconds. If, however, this rate is exceeded for any length of time, it will simply mean that shells of ice containing some water are dispensed.

The evaporator 80 is horizontally mounted upon a vertical shaft 86 supported in bearings 88 and 90 in an upper 92 and a lower 94 bearing plate respectively each fixed at four corners to support pillars 96, 98, 100 and 102. A pressure plate 104 is mounted upon a set of springs 106 equally spaced around a circle centred upon the vertical axis and biassing the pressure plate 104 against a lower surface 108 of the evaporator 80. The support pillars 96, 98, 100 and 102 pass through clearance holes 110 formed in the corners of the pressure plate 104.

As shown in FIG. 4 the evaporator 80 includes sixteen moulds 112 which are cylindrical in form; each constituting a hole passing through the drum from an upper surface 114 to the lower surface 108 and the axis of symmetry of each mould being parallel to the vertical axis. The moulds 112 are equally spaced around a circle centred on the vertical axis.

The pressure plate 104 closes the lower opening of the mould and in order to reduce the effects of friction and stiction and the effects of the formation of ice between the lower surface 108 of the evaporator drum 80 and the pressure plate, the said lower surface 108 and the surface of the pressure plate 104 are coated with a P.T.F.E. such as Teflon. In addition, the surface of the moulds are coated with a coating 81 of P.T.F.E. to facilitate ejection of ice therefrom. To this same end the cylindrical moulds are tapered to have a larger diameter at the lower surface 108.

Indexing of the evaporator drum 80 is effected manually by pulling an operating handle 113 (FIG. 2) connected to a shaft 116 linked by a chain 118 to a ratchet arm 120 in engagement with a gear 123 mounted upon the vertical shaft 86.

Indexing of the evaporator drum 80 is effected by means of a typical ratchet mechanism which includes a gear having sixteen teeth, in correspondence with the number of moulds in the evaporator, and mounted for rotation with the vertical shaft 86. A casing 123 surrounding the gear is mounted for rotation relative thereto and carries a ratchet arm 120. Spring loaded pawl means (not shown) mounted inside the casing engage with the gear teeth and turn the gear when the casing is moved in the direction indicated but to ride over the gear teeth when it is turned in the opposite direction.

The ratchet mechanism is manually operable by pulling a handle 113 connected to a freely rotatable shaft 116 which is linked to the ratchet arm 120. On pulling the handle 113 forward until the ratchet arm 120 contacts a stop 122, the shaft 86 and the drum 80 are displaced through an angle of 22 1/2.degree. (i.e., the angular pitch of the gear teeth and the moulds) and upon release of the handle 113 a return spring (not shown) acts to displace the handle 113 and ratchet arm 120 to the initial position shown in FIG. 2. Contact between the ratchet arm 120 and the stop 122 activates the solenoid means 82 mounted on the upper bearing plate 92 and including a hammer attached to the solenoid core (not shown) which is driven downwardly to strike the top of a block of ice in a mould p located beneath the solenoid means 82 when the solenoid coil is energised. A block of ice ejected from the mould passes through an aperture 105 formed in the pressure plate 104 directly beneath the mould p and into the chute. The mould is empty.

As the return spring acts to displace the operating handle to the initial position a piston 126 is displaced within the cylinder of a pump 128 to supply a measured quantity of liquid through a pipe 130 to the mould b an inlet supply line 131 leads to pump 128.

When liquid is pumped into the mould b there is a tendency for water to seep from the base of the mould and between the lower surface 108 of the evaporating drum 80 and the surface of the pressure plate. In order to minimize the effect of this, refrigerant leaving the evaporator 80 is passed through a pipe 132 located beneath the pressure plate 104 in the region of mould b thereby to cause a skin of ice to form across the bottom of the mould, immediately after liquid is fed into the mould b. This skin of ice serves to seal liquid in the mould b. Alternatively, an additional evaporator may be provided in this position to increase the speed with which the skin of ice forms across the bottom of a mould.

On each occasion that ice is dispensed by the device the evaporator indexes through one position and moulds move from a to p during which time liquid in the moulds is frozen to form a solid block of ice.

The pipe 132 between the evaporator and the condenser may also pass close by an inlet pipe to the pump 128 in order to pre-cool liquid to be frozen.

Refrigerant is fed to the evaporator through a bush 133 fitted in the vertical shaft 86 and maintained stationary by a guide bracket 134 fitted to the lower bearing plate 94. The bore 136 in the bush 113 communicates with a bore 138 in shaft 86 and the bush is sealed by o-ring sealing members 140 and 142 located in grooves 144 and 146 formed in an end portion of the peripheral surface of the bush. Refrigerant passes from the bore 138, through a hole 148 in the shaft 86 transverse to the vertical axis thereof and into a capillary tube 150 wound around the shaft. The capillary tube 150 communicates with a four-way connector (not shown) for distributing refrigerant via four tubes 152 (two shown) passing into the evaporator drum at angular intervals of 90.degree.. The ends of the tubes 152 reach almost to the radially outermost part of the evaporator drum 80 so that flow of refrigerant is from the tubes, radially inwardly of the evaporator drum and through four outlet pipes 154 spaced at angular intervals of 90.degree.; each pipe 154 being spaced at 45.degree. to a tube 152 and being in fluid communication with a bore 156 in the shaft 86. The bore 156 communicates with a bore 158 in a bush 160 (similar to bush 132) maintained stationary by a guide bracket 162 attached to the upper bearing plate 92. The bush 160 is sealed by O-ring sealing members 164 and 166 located in grooves 168, 170 formed in an end portion of the peripheral surface at the bush 160.

By the above described means refrigerant is passed from the stationary supporting structure into the indexable evaporator drum.

FIG. 5 shows a circuit diagram of a solenoid means for ejecting ice from the mould. Contact between the ratchet arm 120 and the stop 122 (FIG. 2) is represented in FIG. 5 by a switch 180 in a low voltage circuit including a relay coil 182 in the secondary circuit of a transformer 184 stepping down the main voltage in the ratio of 230:9. Closure of the switch 180 causes volts to be dropped across the primary of the transformer 184 and across a solenoid coil 186. However, the 230v are shared between the primary coil and the solenoid coil 186 and the solenoid core 188 remains stationary.

Current is induced in the secondary circuit and this causes the relay coil 182 to close relay contact 189 thus dropping 230v across the solenoid coil and reducing the primary volts to zero. The core 188 is then moved downwardly (FIG. 1), to strike the upper surface of ice in a mould, and the relay contact 189 opens once more dropping volts across the primary and energising the relay whereupon the contact 188 is closed and the solenoid is re-energised. The solenoid core 188 is biassed (not shown) to a nonenergised position and, providing switch 180 is closed, the solenoid core is made repeatedly to strike the ice thereby to ensure that the ice is ejected from the mould.

Since the maximum energy of a solenoid occurs at the end of the stroke thereof the solenoid means 82 is so positioned that the core strikes the ice in a mould substantially at the end of its stroke. In order to ensure that excess ice does not accumulate above a mould thereby causing the core to strike ice before the end of its stroke a scraper 190 (FIG. 1) is positioned above a mould 0 to remove excess ice. A similar scraper 192 is positioned adjacent the peripheral edge of the evaporator drum 80 to remove excess ice which may otherwise cause jamming of the evaporator drum.

In addition to the scrapers 190 and 192 a means (not shown) may be provided to apply an impulsive force to the pressure plate 104 when the device has not been in use for some time. This frees that evaporator drum 80 by shattering any film of ice which may have formed (e.g.) between the pressure plate and the evaporator drum.

One difficulty with the device described above with reference to FIGS. 1 to 5 is that when a full measure of liquid to be frozen is supplied to a mould the thermal inertia of the liquid prolongs the formation of a skin of ice at the base of the mould and so liquid seeps between the evaporator and the pressure plate. This can be avoided by initially dispensing only a small quantity of liquid into the mould thus reducing the thermal inertia and enabling the formation of a skin of ice. The mould is then filled with liquid.

Preferably, the two stages are carried out in the two adjacent indexing positions after the ice has been ejected from the mould. As shown in FIG. 4 the moulds are tapered and are disposed such that the cross-sectional area of the mould adjacent the pressure plate is greater than the cross-sectional area remote from the pressure plate. Thus as ice forms in the mould expansion occurs and, because of the direction of the taper, expanding ice tends to separate the pressure plate and the evaporator so that ice forms therebetween. This has a cumulative effect and gives rise to the need for frequent defrosting. If, however, the moulds are inverted so that the larger cross-sectional area is remote from the pressure plate, then as the freezing ice expands the taper causes the ice to life from the mould and thus significantly reduces the force required to eject ice from the mould. In this case blocks of ice are ejected upwardly from the mould.

One drawback with the indexable evaporator type of ice dispenser described above is the need to provide a low friction coating or either or both of the lower surface of the evaporator drum and the upper surface of a pressure plate. This pressure plate acts to retain liquid in the mould prior to freezing during indexing of the drum (see description relating to FIGS. 1 to 4). This is expensive and with extensive use has proved an unsatisfactory solution.

In a preferred form of dispensing device the pressure plate is replaced by a flexible diaphragm retained across the lower opening of a mould in the evaporator.

Referring now to FIG. 6. The annular drum shaped evaporator 80 is mounted for rotation with a vertical shaft 86 supported at upper and lower ends thereof by bearings 88 and 90 in an upper 92 and lower 94 bearing plate respectively. Eight tabs 200 equally angularly spaced around the periphery of the drum shaped evaporator 80 serve to locate an annular plate 202 concentrically with the axis of the evaporator 80 and shaft 96 and the plate 202 is retained in this position by bolts 204 and clamps 206 attached to the tabs 200.

Counterbored holes 208 are equally angularly spaced around the plate 202 is clamped to the evaporator each hole 208 may be positioned beneath one of the moulds 212 formed in the evaporator. Sealing of the lower opening of each of the moulds 212 is effected by a natural rubber diaphragm 213 fitted in the counterbore 214 and closing the hole 208.

The diaphragms 213 are thicker than the depth of the counterbore 214 so that when the plate 202 is clamped against the lower face of the evaporator drum 80, the rubber is tightly compressed to produce an effective seal. Further, the diaphragm 213 is so formed that when fitted in the counterbore it adopts a dished shape.

The plate 202 is preferably injection moulded from a phenolic resin material such as "Delrin" (Registered Trade Mark) and provided with strengthening ribs 203.

In operation the moulds are filled with water (as described above) and each time ice is ejected from the mould, the drum indexes through successive mould positions until the moulds now containing ice are brought into line with means for ejecting ice from the mould.

The means for ejecting ice from the mould (not shown) may be mechanical or electrical and preferably comprise solenoid means 220, wherein a hammer 222 is attached to the solenoid core 224. When the solenoid is energised the core is driven upwardly, in the direction of arrow X, the hammer 222 enters the hole 208 and upwardly deflects the diaphragm 213 which is elastic so as to stretch sufficiently to allow displacement of a central portion thereof through the lower opening of the mould and to provide a force sufficient to eject the ice from the mould.

A piece of ice (not shown) ejected from the mould is projected upwardly into a curved chute 225 which is lined with soft rubber 226 to reduce noise, and rolls around the curved internal surface of the chute in the direction of arrow. The piece of ice then falls on to a pad of rubber 228, which is inclined toward an exit 230 from the chute, so that it rolls gently down the incline and drops through the chute exit 230 and into, for example, a glass.

In this way, a disadvantage of the earlier described embodiment, namely that pieces of ice were ejected at such a velocity that, on occasions, the impact of the ice was sufficient to break a glass, is avoided.

The annular drum shaped evaporator 80 (FIGS. 1, 2, 3 and 6) may be a fabricated structure but as such is expensive to produce. However, the evaporator may be produced by a gravity die casting process. To do this an annular casting is formed with four integral webs. The annular casting is hollow and provided with four peripheral holes each radially aligned with a web through which a core-piece is removed after casting. A radial hole is then drilled through each web and the peripheral holes are then plugged and sealed. These drilled holes correspond to the outlet pipes 154 (FIG. 3).

Alternatively, the evaporator can be formed from two identical stampings 240 and 242 as shown in FIG. 7, welded or brazed together around a peripheral seam 244. The two stampings 240 and 242 are formed with holes 246 and 248 having a peripheral lip 249 and an insert 250 having a tapered bore 252 is fixed in position to form a mould by brazed joints 254 between the peripheral lips 249 and an external surface 256 of the insert 250.

The two stampings define an annular chamber 257 and a hollow web 258 through which the bore 156 communicates with the annular chamber 257 rather than through the four pipes 154 (FIG. 3).

In a preferred form the evaporator 80 is driven by an electric motor which may be actuated to index the evaporator by means of a push button. The evaporator may be driven directly by the motor but preferably the motor is arranged to drive an eccentric peg (not shown) which engages and drives the ratchet arm 120 (FIG. 2).

The motor is started by pressing a push button to energise a relay which is de-energised to switch off the motor after 21/2 seconds, when the evaporator, after turning through 1/16 revolution (viz. one indexing position) opens a fleeting contact on a micro-switch. When the fleeting contact is actuated the solenoid means 220 is operated. During the 21/2 seconds a pump for supplying a measured quantity of liquid into a mould is actuated.

The motor driven device may also include a timer arranged to short out the push button every 20 seconds thereby automatically to dispense ice into a bucket suspended beneath the chute. Preferably, the device includes a limit switch operable to switch off the device when the bucket is full of ice.

If the refrigeration unit is left running, especially in humid conditions, there is a tendency for frost to form on the evaporator and this can lead to jamming of the device. To avoid this the compressor may be switched off by the timer for 10 minutes every 20 minutes. During the 10 minute period the evaporator defrosts but a piece of ice already formed in the mould remains solid due to its thermal inertia. Conveniently the push button overrides the 10 minute period so that the device is not inoperable and to avoid the situation where all the moulds contain water a further override is effective should ice be demanded less than 5 minutes before the beginning of the 10 minute period.

The device may include yet a further evaporator disposed above the drum shaped evaporator assembly and beneath a cover for the device in which is formed a cooling tray for bottles of beer or wine. Alternatively, the refrigerant return pipe may follow a sinuous path beneath the cooling tray.

An ice dispenser may include two or more drum shaped evaporators and may be arranged to dispense ice through separate chutes.

In one form two evaporators are mounted on the same shaft and disposed one above the other, ice being dispensed from one evaporator at one angular location relative to the shaft and from the other evaporator at a location angularly spaced at 180.degree. from the said one angular location. Such an arrangement is particularly advantageous when it is required to dispense ice on each side of a bar counter.

If required, the ice dispensing device may include a coin operated mechanism arranged so that ice can be dispensed only upon insertion of a coin.

The device described above may, of course, be used to dispense any frozen liquid, for example orange juice, simply by replacing water in the system by the liquid to be frozen.

Claims

What I claim is:

1. A device for dispensing ice comprising a refrigeration unit including a container forming an evaporator and comprising an annular drum having inlet and outlet openings for a fluid refrigerant, a plurality of moulds arranged around the axis of the drum, at least a part of the internal surface of each mould being formed by a portion of an external surface of a wall of the container, means for ejecting a piece of ice from one of said plurality of moulds, means for indexing the drum to bring each mould in turn into alignment with the ejecting means and subsequently into alignment with means for supplying liquid to be frozen thereto.

2. A device according to claim 1, wherein the mould or moulds comprise tubular members passing through the container from an upper surface to a lower surface thereof.

3. A device according to claim 2, wherein the bore of each of the tubular members is tapered.

4. A device according to claim 3 wherein the said bore is tapered at an angle of 10.degree..

5. A device according claim 1, wherein the means for ejecting a piece of ice from a mould comprises an electrical solenoid means having a hammer movable, when the solenoid coil is energised, to dislodge the ice and eject it from the mould.

6. A device according to claim 1 and comprising a chute through which ice ejected from a mould is projected.

7. A device according to claim 6, wherein the chute comprises means, located in the path of a piece of ice travelling through the chute, for changing its direction so as to limit the velocity of a piece of ice dispensed from the device.

8. A device according to claim 1 and comprising means for automatically actuating the ejecting means and the liquid supplying means when indexing of the annular drum has been effected.

9. A device according to claim 8, wherein the annular drum is horizontally mounted for indexing relative to a plate biased against a lower face of the drum to form a closure for the moulds and having an aperture in a position corresponding to one index position, wherein the moulds are tapered such that the cross-sectional area of a mould is smaller at the upper surface of the drum than at the lower surface, and wherein the ice ejecting means is disposed above the drum at the said one index position so as to eject ice downwardly from the mould and through the said aperture.

10. A device according to claim 9, wherein the upper surface of the plate and the lower surface of the drum are coated with P.T.F.E.

11. A device according to claim 9 comprising pipe means supplied with refrigerant from the evaporator and located beneath the plate in a position wherein the moulds are aligned with said means for supplying liquid to the mould or moulds.

12. A device according to claim 8 and comprising a flexible diaphragm forming a closure for each mould, wherein the moulds are tapered such that the corss-sectional area of the moulds at the upper surface of the annular drum is larger than the cross-sectional area at the lower surface and wherein the ice ejecting means is disposed below the drum in a position corresponding to one index position thereof so as to eject ice upwardly from the mould.

13. A device according to claim 12, wherein the diaphragm is formed from natural rubber.

14. A device according to claim 1, wherein the annular drum is mounted for angular displacement with a vertical shaft having a bore, a capillery tube connected between the bore and the drum and through which refrigerant is fed to the drum.

15. A device according to claim 14, wherein the annular drum comprises two identical stampings attached together around a peripheral seam and defining an annular evaporator chamber and a hollow web through which refrigerant passes from the said chamber to a second bore in the shaft, and a plurality of tubular inserts each end of which is fitted into a hole in one of the stampings to form a mould.

16. A device according to claim 14, wherein indexing of the evaporator is effected manually by pulling an operating handle connected to a ratchet means mounted on the vertical shaft.

17. A device according to claim 1, wherein the internal surface of the moulds is coated with P.T.F.E.