ICE-MAKING APPARATUS

• US 3,760,600 A
• Filed: 01/13/1972
• Issued: 09/25/1973
• Est. Priority Date: 11/28/1969
• Status: Expired due to Term

• Current Assignee: Hiroichi Osiyama, Hiroshi Kobayashi, Kiyoshi Matsui
• Original Assignee: Hiroichi Osiyama, Hiroshi Kobayashi, Kiyoshi Matsui
• Inventors: Matsui, Kiyoshi, Osiyama, Hiroichi, Kobayashi, Hiroshi
• Primary Examiner(s): Wayner, William E.
• Application Number:
  US05/217,474
• Time in Patent Office: 621 Days
• Field of Search: 62/348,188,137,135,352 137/392
• US Class Current: 62/137
• CPC Class Codes: F25B 2600/0251 with on-off operation
• CPC Class Codes: F25C 1/12 by freezing water on cooled surfaces, e.g. to form slabs
• CPC Class Codes: F25C 2700/04 Level of water
• CPC Class Codes: G01F 23/241 for discrete levels
• CPC Class Codes: Y10T 137/7306 Electrical characteristic sensing

Abstract

Improved ice-making apparatus in which water stored in a water pan is cyclically sent onto the surface of an evaporator to make an ice plate while at the same time detecting the water level in the water pan to switch the evaporator to a high-temperature operation, a very small current being made to flow between a plurality of electrodes immersed in the water in said water pan, which current is amplified to energize a detector relay for accurate water-level detection, a switch being provided which puts said evaporator into a cooling operation immediately after detection of a removal of ice.

Claims

1. An ice-making apparatus comprising:

a loop freezing circuit formed by a compressor, a condenser, a capillary tube, and an evaporator connected together into a loop therewith;

a bypass conduit for bypassing said condenser and said capillary tube so as to connect an output of said compressor to an input of said evaporator;

a refrigerant valve adapted to be opened and closed for allowing a refrigerant to pass through said bypass conduit from said compressor to said evaporator when it is opened;

a water pan for storing water therein;

a water supply valve adapted to be opened and closed for allowing water to pass therethrough into said water pan when it is opened;

a water pump for supplying water in said water pan onto said evaporator so as to let water fall down along outer periphery of said evaporator;

a water guide member for guiding water flown down from said evaporator back to said water pan; and

a heater for cutting an ice plate formed on and released from said evaporator into lumps of ice so as to cause said lumps to fall down;

wherein a control device for controlling the operation of said ice-making apparatus comprises;

a. a water level detector for generating first and second signals, said first signal being generated when a water level in said water pan reaches above a predetermined high level and being maintained until the water level reaches below a predetermined low level, said second signal being generated when the water level reaches below the predetermined low level and being maintained until the water level reaches above the predetermined high level;

b. first switch means adapted to be actauted to cause said pump to be actuated so long as the first signal is maintained;

c. second switch means adapted to be actuated to open said refrigerant valve so long as the second signal is maintained;

d. a thermostat provided on said evaporator, said thermostat being adapted to be actuated when the temperature of said evaporator reaches above a predetermined high temperature at which no ice can adhere to said evaporator and adapted to be relieved from the actuation thereof when the temperature of said evaporator reaches below a predetermined low temperature at which ice can be formed;

said water supply valve being opened while said second switch means and said thermostat are actuated simultaneously, e. a first ice-detection switch adapted to be actuated so long as an ice plate formed on and released from said evaporator is present on said heater, said first ice-detection switch being connected in parallel to said thermostat, so that said water supply valve is opened while said second switch means and at least one of said thermostat and said first ice-detection switch are actuated simultaneously, and f. a second ice-detection switch adapted to be actuated so long as no ice exists on said heater, said second ice-detection switch being connected in series with said second switch means, so that said refrigerant valve is opened while said second switch means and said second ice-detection switch are actuated simultaneously.

2. The control device for an ice-making apparatus according to claim 1, wherein said water level detector comprises:

first and second electrodes provided in said water pan at the predetermined high and low levels, respectively, said first electrode being adapted to contact with the water only when the water level reaches above the predetermined high level, said second electrode being adapted to contact with the water while the water level reaches above the low level;

a common electrode provided at a predetermined position below the predetermined low level in said water pan;

an electric power source having two terminals, one of said terminals being connected to said common electrode and the other one of said terminals being connected to said first and second electrodes to thereby cause a current from said power source to flow between said common electrode and at least one of said first and second electrodes;

an amplifier adapted to amplify the current so as to produce an amplified out-put current; and

a relay having a contact adapted to be closed when said relay is energized by the output current of said amplifier, said contact being connected in series with said second electrode and said power source, so that said relay is maintained in its energized state until the water level reaches below the predetermined low level once said relay is energized, said first switch means being adapted to be actuated so long as said relay is energized, said second switch means being adapted to be actuated so long as said relay is not energized.

3. The control device for an ice-making apparatus according to claim 2, wherein said refrigerant valve has a first solenoid coil adapted to be energized through said second switch means, and said water supply valve has a second solenoid coil adapted to be energized through being in series with said second switch means and said thermostat.

4. An ice-making apparatus comprising:

a freezing system including a compressor;

a condenser connected to said compressor;

a capillary tube connected to said condenser;

an evaporator connected between said capillary tube and said compressor, said condenser, said capillary tube and said evaporator forming a closed freezing circuit;

a bypass conduit for introducing a refrigerant gas from said compressor to said evaporator; and

a refrigerant valve disposed in said bypass conduit adapted to be opened and closed in response to actuation and non-actuation of a solenoid coil therefor, respectively;

a water system including a water pan, a water supply valve adapted to be opened and closed in response to actuation and non-actuation of a solenoid coil therefor respectively so that water is supplied to said water pan through said water supply valve while it is opened, a pump for supplying water in said water pan onto said evaporator, and a guide member for guiding water thus supplied onto said evaporator back into said water pan; and

a heater for receivng an ice plate formed on and released from said evaporator and for cutting said ice plate into lumps thereof so as to let them fall down, wherein a control device for said ice-making apparatus comprises;

a. a water level detector including first and second electrodes provided in said water pan at predetermined high and low positions which set the water level in said water pan at predetermined high and low limits, respectively, a common electrode provided in said water pan at a predetermined position below the predetermined low limit, an electric power source having two terminals connected to said common electrode at one terminal thereof and to said first and second electrodes at the other terminal thereof so as to cause a current to flow between said common electrode and at least one of said first and second electrodes, an amplifier for amplifying the current so as to produce an amplified output current, and a relay adapted to be excited by the amplified output current, said relay having first, second and third relay switches, both said first and second relay switches being adapted to be closed while said relay is excited, said third relay switch being adapted to be opened while said relay is excited, said first relay switch being connected in series to said power source and said second electrode;

b. a thermostat provided on said evaporator said thermostat being adapted to be closed when the temperature of said evaporator exceeds a predetermined value at which no ice can adhere to said evaporator and adapted to be opened when the temperature of said evaporator reaches below a predetermined low value at which ice can be formed;

c. means for supplying electric power to said solenoid coil for said water supply valve through said tHird relay switch and said thermostat so as to cause said water supply valve to be opened while said third relay switch and said thermostat are closed concurrently;

d. means for supplying electric power to said solenoid coil for said refrigerant valve through said third relay switch so as to cause said refrigerant valve to be opened while said second relay switch is closed;

e. means for supplying electric power to said pump through said seocnd relay switch so as to cause said pump to be actuated while said second relay switch is closed, f. a first ice-detection switch adapted to be actuated so long as an ice plate formed on and released from said evaporator is present on said heater, said first ice-detection switch being connected in parallel to said thermostat, so that said water supply valve is opened while said second switch means and at least one of said thermostat and said first ice-detection switch are actuated simultaneously, and g. a second ice-detection switch adapted to be actuated so long as no ice exists on said heater, said second ice-detection switch being connected in series with said second switch means, so that said refrigerant valve is opened while said second switch means and said second ice-detection switch are actuated simultaneously.

5. An ice-making apparatus comprising:

a freezing system having a closed circuit including a compressor for compressing a refrigerant, a condenser, a capillary tube and an evaporator, a bypass conduit for introducing a refrigerant gas from said compressor to said evaporator, and a refrigerant valve disposed in said bypass conduit;

a water system having a water pan, a water supply valve for supplying water therethrough to said water pan, a pump for supplying water onto said evaporator and a guide member for guiding water back from said evaporator to said water pan;

a heater for receiving an ice plate formed on and released from said evaporator and for cutting said ice plate into lumps thereof to thereby let them fall down; and

a control device for said ice-making apparatus comprising;

a. a water level detector including two electrodes disposed in said water pan for setting the water level in said water pan at predetermined high and low limits respectively, a common electrode disposed in said water pan which can be conducted via water to said two electrodes, and an electric power supply source connected at one terminal thereof to said common electrode and at the other terminal thereof to said two electrodes, b. an amplifier adapted to amplify a current flowing between said common electrode and at least one of said two electrodes, c. a relay adapted to be excited by an output current of said amplifier, d. a first relay switch adapted to be closed in response to excitation of said relay, said first relay switch is connected in series to said power supply source and one of said two electrodes for setting the low limit of said water level, e. a second relay switch adapted to be closed in response to the excitation of said relay for actuating said pump while it is closed, f. a third relay switch adapted to be opened in response to the excitation of said relay, g. a thermostat installed on said evaporator, said thermostat adapted to be closed when the temperature of said evaporator exceeds a predetermined level for preventing said evaporator from over-heating, h. a water solenoid valve coil adapted to be energized through said third relay switch and said thermostat to thereby open said water supply valve, i. a solenoid valve coil for said refrigerant valve adapted to be energized through said third relay switch to thereby open said refrigerant valve, j. a first ice-detection switch adapted to be actuated so long as an ice plate formed on and released from said evaporator is present on said heater, said first ice-detection switch being connected in parallel to said thermostat, so that said water supply valve is opened while said second switcH means and at least one of said thermostat and said first ice-detection switch are actuated simultaneously, and k. a second ice-detection switch adapted to be actuated so long as no ice exists on said heater, said second ice-detection switch being connected in series with said second switch means, so that said refrigerant valve is opened while said second switch means and said second ice-detection switch are actuated simultaneously.

6. An ice-making apparatus comprising:

a freezing system having a closed circuit including a compressor for compressing a refrigerant, condenser, a capillary tube and an evaporator, a bypass conduit for introducing a refrigerant gas from said compressor to said evaporator, and a refrigerant valve disposed in said bypass conduit;

a water system having a water pan, a water supply valve for supplying water therethrough to said water pan, a pump for supplying water onto said evaporator and a guide member for guiding water back from said evaporator to said water pan;

a heater for receiving an ice plate formed on and released from said evaporator and for cutting said ice plate into lumps thereof to thereby let them fall down; and

a control device for said ice-making apparatus comprising;

a. a water level detector including two electrodes disposed in said water pan for setting the water level in said water pan at predetermined high and low limits respectively, a common electrode disposed in said water pan which can be conducted via water to said two electrodes, and an electric power supply source connected at one terminal thereof to said common electrode and at the other terminal thereof to said two electrodes, b. an amplifier adapted to amplify a current flowing between said common electrode and at least one of said two electrodes, c. a relay adapted to be excited by an output current of said amplifier, d. a first relay switch adapted to be closed in response to excitation of said relay, said first relay switch is connected in series to said power supply source and one of said two electrodes for setting the low limit of said water level, e. a second relay switch adapted to be closed in response to the excitation of said relay for actuating said pump while it is closed, f. a third relay switch adapted to be opened in response to the excitation of said relay, g. a thermostat installed on said evaporator, said thermostat adapted to be closed when the temperature of said evaporator exceeds a predetermined level for preventing said evaporator from over-heating, h. a water solenoid valve coil adapted to be energized through said third relay switch and said thermostat to thereby open said water supply valve, i. a solenoid valve coil for said refrigerant valve adapted to be energized through said third relay switch to thereby open said refrigerant valve, j. a detecting switch for detecting removal of an ice plate from said evaporator, said detecting switch having a first contact switch adapted to be closed and a second contact switch adapted to be opened so long as an ice plate exists on said heater, respectively, and k. means for connecting said first contact switch in parallel with said thermostat, said second contact switch being connected in series to said third relay switch and said solenoid valve coil for said refrigerant valve.

7. An ice-making apparatus according to claim 6, in which said amplifier in said contol device includes a transistor whose base current is controlled by a current flowing between said common electrode and at least one of said two electrodes, said relay being constructed in such a manner as to be energized by a collector current of said transistor, thereby minimizing the current flowing between the electrodes while making a large current flow in said relay to ensure accurate operations.

8. An ice-making apparatus according to claim 1, in which said control device is also equipped with a switch which is opened by detecting a maximum amounT of ice produced, whereby said compressor, said water solenoid valve coil, said solenoid valve coil and said circulating pump are de-energized, a cooling operation being started immediately after a removal of ice.

9. A control device for an ice-making apparatus having:

a water pan;

water supply means for operatively supplying water into said pan;

an evaporator;

a water pump for operatively supplying water in said pan onto said evaporator to flow down along an outer wall of said evaporator;

a guide member for guiding water back from said evaporator to said pan;

refrigerant means for supplying to said evaporator a refrigerant in one of a compressed gaseous state and in a condensed liquid state so as to operate said evaporator in an ice-removing condition and in a cooling condition, respectively, and a heater for receiving an ice plate formed on and then released from said evaporator and for cutting the ice plate into lumps of ice so as to cause said lumps to fall down;

said control device comprising;

a. a water level detector for generating a detection signal when a water level in said pan exceeds a predetermined high level, said detection signal being maintained until the water level falls below a predetermined low level;

b. first switch means actuated while said detection signal lasts for operatively actuating said pump;

c. a thermostat provided on said evaporator and actuated when the temperature of said evaporator exceeds a predetermined high temperature at which ice can be removed from said evaporator, the actuation of said thermostat being maintained until the temperature of said thermostat falls below a predetermined low temperature at which ice can be formed;

d. second switch means actuated while said detection signal is not generated;

e. a first ice detection switch actuated while said heater receives an ice plate thereon; and

f. a second ice detection switch actuated while no ice plate exists on said heater;

said refrigerant means being controlled to operatively supply to said evaporator the refrigerant in the compressed gaseous state only while said second switch and said first ice detection switch are concurrently actuated, and otherwise supplying the refrigerant in the condensed liquid state, said water supply means being actuated to supply water into said water pan only while said second switch means and at least one of said thermostat and second ice detection switch are concurrently actuated.

10. The control device according to claim 9, wherein said water level detector comprises:

first and second electrodes provided in said water pan at the predetermined high and low levels, respectively;

a common electrode provided in the water in said water pan so that said common electrode is connected through the water to said first and second electrodes when the water level in said water pan reaches said predetermined high and low levels, respectively;

an electric power source with two terminals one of which is connected to said common electrode and the other of which is connected to said first and second electrodes, respectively;

an amplifier for amplifying an electric current flowing between said common electrode and at least one of said first and second electrodes through the water in said water pan; and

a relay responsive to said amplifier and which is rendered one of on and off in response to one of an on and off condition of the electric current through the water, respectively;

said relay having a first contact switch which is closed when said relay is rendered on and connected between said second electrode and said other terminal of said power source, a second contact switch which is closed when said relay is rendered on and acts as said first switch means, and a third contact switch which is closed when said relay 1s rendered off and acts as said second switch means.

11. In an ice-making apparatus having:

a water pan;

water supply means for operatively supplying water into said pan;

an Evaporator;

a water pump for operatively supplying water in said pan onto said evaporator allowing water to flow down along an outer wall of said evaporator;

a guide member for guiding water back from said evaporator to said pan;

refrigerant means for supplying to said evaporator a refrigerant in one of a compressed gaseous state and a condensed liquid state so as to operate said evaporator in either an ice-removing condition or a cooling condition, respectively;

a heater for receiving an ice plate formed on and then released from said evaporator and for cutting the ice plate into lumps of ice so as to cause said lumps to fall down;

a water level detector for generating a detection signal when a water level in said pan exceeds a predetermined high level, said detection signal being maintained until the water level falls below a predetermined low level;

a power source;

first switch means actuated while said detection signal lasts for connecting said power source to said pump so as to operatively actuate said pump;

a thermostat provided on said evaporator and actuated when the temperature of said evaporator exceeds a predetermined high temperature at which ice can be removed from said evaporator, the actuation of said thermostat being maintained until the temperature of said thermostat falls below a predetermined low temperature at which ice can be formed; and

second switch means actuated while said detection signal is not generated;

the improvement comprising;

a. a first ice detection switch actuated while said heater receives an ice plate thereon for operatively shunting said thermostat; and

b. a second ice detection switch connected in parallel to said thermostat and actuated while no ice plate exists on said heater;

said power source being connected in series to said refrigerant means through said second switch means and said first ice detection switch only while said second switch means and said first ice detection switch are concurrently actuated so that said refrigerant means operatively supplies to said evaporator the refrigerant in the gaseous state, and otherwise supplies the refrigerant in the condensed liquid state, and said power source being connected to said water supply means through said second switch means and the parallel circuit of said thermostat and said second ice detection switch so that said water supply means operatively supplies water into said pan only while said second switch means and at least one of said thermostat and said second ice detection switch are concurrently actuated.