US3885937A - Ice machine control mechanism - Google Patents

Abstract

An ice making machine is disclosed which includes a double walled cylindrical evaporator on which ice is formed from water deposited on the evaporator, and a closed loop refrigeration system for freezing the water on the evaporator during a freezing cycle, and defrosting the ice formed to cause it to drop from the evaporator during a harvest cycle. The fallen ice is crushed by a crusher motor and stored in a bin having a bin level control. Should the bin control be energized prior to completion of a freeze cycle, a switch is provided for automatically overriding the bin control until a complete freezing, harvesting and crushing cycle has been completed.

Description

Norris 1 May 27, 1975 1 1 ICE MACHINE CONTROL MECHANISM [76] lnventor: Russel W. Norris, 1911 Chaparral,

Houston, Tex. 77043 [22] Filed: Jan. 12, 1973 [21] Appl. No.: 323,209

Primary Examiner--Wil1iam E. Wayner Attorney, Agent, or Firm-Hubbard, Thurman, Turner & Tucker [5 7 ABSTRACT An ice making machine is disclosed which includes a double walled cylindrical evaporator on which ice is formed from water deposited on the evaporator, and a closed loop refrigeration system for freezing the water on the evaporator during a freezing cycle, and defrosting the ice formed to cause it to drop from the evaporator during a harvest cycle. The fallen ice is crushed by a crusher motor and stored in a bin having a bin level control. Should the bin control be energized prior to completion of a freeze cycle, a switch is provided for automatically overriding the bin control until a complete freezing, harvesting and crushing cycle has been completed.

2 Claims, 5 Drawing Figures WATER OUT WATER \N REFRIG. CYCLE CONTROL Z3 ICE MACHINE CONTROL MECHANISM This invention relates to the control of ice machines of the type having an elongated cylindrical evaporator on which ice is formed.

Machines of this type, particularly where a double walled hollow evaporator is provided so that ice can be formed on each wall, provide for the freezing of relatively large quantities of ice in a relatively short period of time as opposed to other types of ice machines. These machines are also very economical, and dependable, and very simple to maintain since only a few moving parts are involved. These machines include apparatus for'applying water to the evaporator, a refrigeration system for freezing the water and then defrosting or harvesting the ice formed, an ice crusher for crushing ice formed as it falls from the evaporator, and a storage bin for the crushed ice. A complete cycle of the machine includes freezing of the ice, harvesting of the ice, and crushing and storing the ice. In such machines it is common to provide the storage bin, into which formed ice is accumulated, with a bin level control switch, such as a thermostat, which stops the forming of ice when the bin is full. However, since these types of machines initially form a large cylindrical piece of ice which falls from the evaporator to an ice crusher during a harvest cycle, the crusher can be easily jammed if it is not running when this occurs. However, in the prior machines of the type described herein, the bin control is effective to cause the ice making cycle to stop whenever the bin level control is activated, which can occur during a normal freeze cycle if a piece of ice should fall against the thermostat bulb, or if the machine is outside because of cold weather. If the complete machine cycle is not completed, then the referred to jamming can occur.

It is thus an object of this invention to provide an ice making machine of this type described, but in which chances of jamming the ice crushed are substantially reduced.

Another object of this invention is to provide such an ice machine having a bin level control, and in which the above stated object is accomplished by rendering the bin level control ineffective until a complete cycle of the machine, including crushing of harvested ice, is completed. In the preferred embodiment of this invention illustrated this is accomplished by shunting the bin level control switch with the contacts of a switch or relay that is responsive to a timer (electrical or mechanical) controlling the operating cycle of the ice machine, so that the bin control switch remains shunted until the timer has reached a position (or a point in time) indicative of a complete freeze cycle of the machine.

Other objects and advantages of this invention will be apparent upon consideration of the appended claims and drawings, and upon consideration of the detailed description herein.

In the drawings, wherein like reference numerals are used throughout to designate like parts, and wherein a preferred embodiment of this invention is disclosed;

FIG. 1 is a schematic diagram of a cylindrical evaporator type ice maker employing the present invention;

FIG. 2 is a detailed wiring diagram of the cycle control circuits of the ice maker of FIG. 1;

FIG. 3 is a schematic side view of the ice bin of the FIG. 1 ice maker;

FIG. 4 is a schematic view of an alternate arrangement of the ice bin, and

FIG. 5 is a side view schematically of the ice bin of FIG. 4.

Referring to FIG. 1, an ice making machine 10 is illustrated as including a double walled cylindrical evaporator 11, having an inner wall 11A and outer wall 118, and a sealed annulus between 11C the walls into which a refrigerant is introduced. Water, such as from a nozzle 12 which obtains water from a water pump 12A and sump 12B, is frozen by the refrigerant on the surface of walls 11A and 118 to form a unitary, cylindrical chunk of ice 13 during a freezing cycle of machine 10. Of course, the components of FIG. 1 may be mounted on a frame or in a cabinet to form an integrated ice making machine. Cold refrigerant is supplied to annulus 11C through tubing 14A and after heat exchange with the water being frozen is exhausted as a gas through tubing 14B to a refrigeration system for condensing the gas refrigerant in the normal manner. As illustrated, the refrigeration system is conventional and includes a compressor 15, water cooled heat exchanger 16, a refrigeration control cycle circuit 17 which controls the operating cycle of machine 10, and a hot gas solenoid valve 15A for permitting hot gas to flow to evaporator 11. As is conventional in such a machine, circuit 17 (which may include an electrical or mechanical clock or timer) causes machine 10 to freeze water on evaporator 11 during a freeze cycle for a short period of time, and then the refrigeration system is caused to reverse and hot gas is supplied through valve 15A to annulus 11C during a harvest cycle for defrosting evaporator 11 for a present time sufficient to allow the ice to fall from the evaporator. An ice crusher 18 located below evaporator 11 is turned on during the harvest cycle to crush ice 13 as it falls from evaporator 11. Crushed ice travels down a chute 19 from crusher 18 to a storage bin 20. Storage bin 20 includes a bin level control element 21 which may be a thermostat element 21, which is sensitive to temperature, to control the opening and closing of a bin control switch, as to be described with reference to FIG. 2. The bin level control switch is normally connected to circuit 17 in a manner to shut down the ice making operation of machine 10 when bin 20 is full.

In operation, particularly where bin 20 is located outside during cold weather, element 21 and its corresponding bin control switch may be inadvertantly operated to prematurely shut down ice maker 10 before a freeze cycle is completed and before crusher 18 is turned on. An important feature of the present invention is that means is provided for delaying this shut off until any ice formed on evaporator l 1 has been crushed by crusher 18.

The control circuitry for this purpose is illustrated in FIG. 2. A.C. Power (for example 230 volts at 60 cycles) is provided at terminals 22 and 23. An off-on switch 24 is connected to terminal 23 to provide switched A.C. to a terminal 24. Terminal 22 provides a common A.C. source to which one side of the electrical windings of the various components of ice machine 10 is connected, and the other side of the electrical windings of each these components is connected through the contacts of a relay, or the contacts of a timer controlled switch to terminal 24. As illustrated in FIG. 2, a timer motor 26 is drivingly connected to a cam 26A which in turn controls the opening and closing of a switch 26B, which has a pole contact and two terminal- contacts 25 and 28. Cam 26A includes a lobe 26C which forces switch 268 closed against terminalcontact 25 during a portion of a complete revolution of the cam at which time a freeze cycle is in progress in machine 10, and a valley portion 26D for most of the remainder of the revolution of the cam during which time switch 26A is in a position with its pole contact in contact with terminal-contact 28, and ice harvesting and crushing is in progress. Cam 26A also includes a smaller lobe portion 26D leading to lobe portion 26E during which time switch 26B is intermediate terminal- ;ontacts 25 and 28. When switch 268 is closed, A.C. current is conducted from terminal 24 to terminalcontact 25. Bin control switch 21A is connected to terminal-contact 25 and to the coil of a DPST relay 27 which includes one set of normally open contacts 27A which are connected to shunt bin control switch 21A and a second set of normally open contacts 278 connected between terminal 24 and the side of compressor not connected to terminal 22. When timer switch 268 is closed to terminal-contact 28, terminal 24 is connected to terminal-contact 28 and a crusher motor l8A for driving ice crusher 18, and hot gas solenoid valve 15A, and the coil of a DPST relay 29 which are connected between terminal 22 and a terminal-contact 28 are activated by A.C. current. Relay 29 includes normally open contacts 29A connected across contacts 378, and normally closed contacts 29B connected between contacts 29A and the side of water pump 12A not connected to terminal 22. Thus, if either of contacts 278 or 29A are closed, then compressor 15 will be on, and timer motor 26, which is connected across it, will be running.

During a normal freeze cycle of machine 10, (illus- Trated in FIG. 2) switch 23 is closed, switch 268 is normally set on lobe 26C (at the start of the freeze cycle) of cam 26A so that terminal 24 is connected to terminal-contact 25. and bin switch 21A is closed. Thus, the circuit between terminal 24 and relay 27 is complete so that this relay is activated closing contacts 27A and .378. As noted, contacts 27A shunt bin switch 21A, and contacts 278 connect compressor 15 and timer motor to the AC, current to turn them on. Also, since contacts 278 close, water pump 12A is also turned on. This state of the circuitry continues until switch 268 drops off the other end of lobe 26C to connect terminal-contact 28 to terminal 24 and disconnect terminalcontact 25 from terminal 24. When this occurs, crusher motor 18A, hot gas valve 15A and the coil of relay 29 are connected to A.C. current and activated, starting a harvest cycle, closing relay contacts 29A, and opening relay contacts 298. Thus, compressor 15 and timer motor 26 remain running, but water pump 12A is turned off. Hot gas is routed through evaporator 11 and crusher motor 18 crushes ice falling from evaporator l1. At the end of this cycle switch 26B is engaged by intermediate lobe 26E so that electrical current is not provided to either of terminal- contacts 25 and 28, and the ice machine 15 at rest.

When bin level control switch 21A opens clue to being full or because of cold weather, even when only ,1 part of the freeze cycle is completed, relay 27 will remain activated by reason of its own contacts 27A shunting bin switch 21A until switch 268 switches from terminal-contact 25 to terminal-contact 28. Thus, the ice maker will be permitted to complete its freeze cycle and subsequent harvest cycle before shunt off. Heretofore, when shut down occurred prior to the end of the freeze cycle, and contact 27A was not provided to shunt bin switch 21A, relay 27 would drop out prematurely, and before switch 268 would be switched from terminal-contact 25 to terminal contact 28, so that the cycle of the machine would not be completed, before ice would fall into the now off ice crusher, and jamming would occur when the crusher was subsequently turned From the foregoing, it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages that are obvious and that are inherent to the apparatus.

It will be understood that certain features are subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed 1. In an ice making machine having a double walled cylindrical evaporator on which ice is formed from water deposited on the evaporator, a closed loop refrigeration system including a timer for providing a freezing cycle for such water and a harvest cycle for the ice formed on said evaporator, an ice crusher located below said evaporator for crushing ice as it falls from the evaporator during said harvest cycle, an ice bin for collection and storage of said ice and having a thermostat which includes a sensing element and a switch element connected to shut off power to said refrigeration system for sensing the level of said ice in said bin to provide a stop signal for stopping the further making of ice on said evaporator until the ice in the bin has fallen below a predetermined level, the improvement comprising, means for causing the in process cycle of freezing, harvesting, and crushing the ice to be completed when said stop signal is provided prior to the end of a freeze cycle, said means comprising a control switch shunting said switch element, said control switch including the contacts of a relay connected so that said contacts are closed during the freeze cycle irrespective of the state of said thermostat switch element.

2. The ice machine of claim 1 wherein said timer includes a timer motor and a switch element operable in response to said timer motor to control the operating cycle of the ice machine, and wherein said thermostat includes a second switch element for controlling current to said timer motor and said control switch is connected to prevent disruption of power to said timer motor during a freeze cycle.

Claims (2)

1. In an ice making machine having a double walled cylindrical evaporator on which ice is formed from water deposited on the evaporator, a closed loop refrigeration system including a timer for providing a freezing cycle for such water and a harvest cycle for the ice formed on said evaporator, an ice crusher located below said evaporator for crushing ice as it falls from the evaporator during said harvest cycle, an ice bin for collection and storage of said ice and having a thermostat which includes a sensing element and a switch element connected to shut off power to said refrigeration system for sensing the level of said ice in said bin to provide a stop signal for stopping the further making of ice on said evaporator until the ice in the bin has fallen below a predetermined level, the improvement comprising, means for causing the in process cycle of freezing, harvesting, and crushing the ice to be completed when said stop signal is provided prior to the end of a freeze cycle, said means comprising a control switch shunting said switch element, said control switch including the contacts of a relay connected so that said contacts are closed during the freeze cycle irrespective of the state of said thermostat switch element.

2. The ice machine of claim 1 wherein said timer includes a timer motor and a switch element operable in response to said timer motor to control the operating cycle of the ice machine, and wherein said thermostat includes a second switch element for controlling current to said timer motor and said control switch is connected to prevent disruption of power to said timer motor during a freeze cycle.

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