US3126714A

US3126714A - zuercher

Info

Publication number: US3126714A
Authority: US
Publication date: 1964-03-31
Anticipated expiration: 1981-03-31

Description

March 31, 1964 E. A. ZUERCHER, JR 3,126,714

AUTOMATIC ICE MAKER Filed May 10, 1962 2 Sheets-Sheet 1 F 'Ie, .28

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F'IGZ INVENTOR. EDWARD A ZUERCHER JR BY Z/MWL l-HS ATTORNEY Mam}! 1964 E. A. ZUERCHER, JR 3,126,714

AUTOMATIC ICE MAKER Filed May 10, 1962 2 Sheets-Sheet 2 INVENTOR. EDWARD A. ZUERCHER 3R H(S ATTORNEY United States Patent 3,125,714 AUTGMATIQ IQE MAKER Edward A. Zuercher, Ira, Fern Creek, Ky, assignor to General Electric Company, a corporation of New Yorl: Filed May 11" 1962, Ser. No. 193,746 3% (Ilaiins. (Cl. 62137) The present invention relates to an automatic ice maker and is particularly concerned with a compact ice maker adapted to be incorporated in a domestic or household refrigerator.

An object of the present invention is to provide a new and improved domestic or household refrigerator ice maker including a mold or tray containing a plurality of cavities from which ice pieces are released by centrifugal forces resulting from rotation of the mold about a vertical axis.

Another object of the present invention is to provide an automatic ice maker including a mold and means for rotating the mold for centrifugal discharge of ice pieces therefrom and centrifugally operated control means for stopping the operation of the ice maker when the required quantity of ice has been manufactured.

A further object of the invention is to provide an automatic ice maker including means for centrifugally discharging ice pieces from an ice mold and control means for initiating the ice harvesting cycle in response to a subfreezing temperature of the ice mold and for terminating the harvesting cycle as soon as the ice pieces have been centrifugally removed from the mold.

Additional objects and advantages of the invention will become apparent as the following description proceeds and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

In carrying out the objects of the present invention, there is provided an ice mold including a plurality of cavities or pockets from which ice pieces formed therein can be centrifugally discharged by rotation of the mold about a vertical axis. The ice mold is preferably of annular shape and comprises a plurality of radially extending pie-shaped cavities including radially extending side walls and sloping end Walls adjacent the periphery of the mold whereby rotation of the mold about its center or axis will cause the ice pieces formed in the mold cavities to be centrifugally discharged therefrom. To facilitate the release of the ice pieces, the mold is preferably composed not only of a plastic material such as polystyrene, polyethylene or the like having a low adhesion for ice but is also SllffiClGl'lilY resilient or flexible so that flexing or distortional vibrations will be set up in the mold during rotation to facilitate the breaking of the ice bond with the cavity surfaces.

For the purpose of stopping the operation of the ice maker when the required quantity of ice has been collected in a storage receptacle associated with the ice maker, there is also provided a centrifugally operated level sensing means operated by the same drive means employed to rotate the mold during the ice harvesting cycle and adapted to be centrifugally raised from its sensing position during each harvesting cycle and to stop operation of the ice maker in the event it does not return to its sensing position when rotation of the mold is stopped In its preferred form, the ice maker also includes control circuitry for initiating the harvesting cycle, that is rotation of the ice mold, when the mold attains a predetermined sub-freezing temperature and to stop the rotation :as soon as the ice pieces have been centrifugally discharged from the mold.

For a better understanding of the invention, reference may be had to the accompanying drawings in which:

FIGURE 1 is a front elevational view of the freezer compartment of a household refrigerator having positioned therein the ice maker of the present invention;

FIGURE 2 is a view taken generally along line 2-2 of FIGURE 1;

FIGURE 3 is a sectional view of the ice maker taken generally along line 3-3 of FIGURE 2; and

FIGURE 4 is a wiring diagram for an electric control system employed for the automatic control of the ice maker of the present invention.

As illustrated in FIGURE 1 of the drawing, the ice maker of the present invention indicated by the numeral 1 is designed to be positioned in the freezing chamber 2 of a household refrigerator which is refrigerated by air circulated by means of a fan 3 over an evaporator 4. Preferably the ice maker is positioned immediately in front of an outlet 5 for the air which has been circulated over and cooled to sub-freezing temperatures by the evaporator. Also positioned within the freezer compartment 2 immediately below the ice maker is a receptacle or bin 6 in which ice pieces discharged from the ice maker are stored in an ambient temperature below freezing.

With reference particularly to FIGURE 3 of the drawing the ice maker comprises a support 7 secured by any suitable means to one side wall 8 of the compartment 2 and the support '7 includes a base 9 on which a motor 10 including a drive shaft 11 is vertically mounted. An annular ice mold 312 is mounted on the upper end of the shaft 11 in such a manner that it will rotate with the shaft upon operation of the motor 16) but is also free to move vertically on the shaft within limiting positions. In the illustrated embodiment of the invention the driving connection between the shaft -11 and the mold 12 com prises a drive dog 14 mounted on the shaft and a drive boss 15 secured to the hub portion of the ice mold 12. By this arrangement, the pins 16 forming part of the dog 14 slidably extend into cylindrical recesses 17 in the drive boss to provide a rotational driving force to the mold 12 upon rotation of the shaft 11. The drive boss 15 forming the hub of the rotatable ice mold is loosely fitted on the shaft 11 so that the ice mold 12 is free to move vertically between an upper position in which the central portion of the mold d2 contacts a stop 18 carried by the shaft 11 and a lower position in which the lower surface Zll of the drive boss rests on the drive dog 14. A spring 21 is provided for biasing the ice mold to its upper position and is of the strength such that the ice mold will be held in its upper position when empty but will move to its ower position when filled with water or ice.

The ice mold 12 as illustrated also in FIGURE 2 of the drawing includes a plurality of ice pockets or cavities 22 which are generally pie-shaped or in other words are each defined by radially extending

opposed side walls

23 and 24 and a sloping outer or peripheral wall 25. By this configuration or any similar configuration in which the outer or peripheral dimensions of the individual cavities 22 are the larger and the

side walls

23 and 24 converge towards the axis 27 of the mold, ice pieces formed therein can be discharged from the cavities by centrifugal forces resulting from rotation of the mold about its axis 27. For the purpose of allowing a charge of water to flow from cavity to cavity, notches 26 are provided in the outer ends of the side walls.

Preferably the mold 122 is composed of a resilient or somewhat flexible plastic material such as polystyrene, polyethylene or the like. By the use of molds of this type, the centrifugal forces on the ice pieces during rotation of the mold cause the ice pieces to break loose from the mold and fly out of the mold. The release and discharge action is accelerated by any unbalance in the mold which causes distortion or vibration thereof during rotation. If desired an unbalance can be deliberately built into the mold as for example by arranging to have diametrically opposite portions of the mold somewhat heavier than the remaining portions to force distortion of the resilient material upon rotation thereof. Normally however it has been found that the small amount of unbalance present in the usual mold as manufactured is sufficient to cause quick release of the ice pieces during rotation.

For the purpose of periodically supplying a charge of water to the mold, there is provided a water supply means including an outlet 27 positioned above the mold 12 and a solenoid operated water valve (shown schematically in FIGURE 4) which may be disposed in the high temperature compartment 28 of the refrigerator or in the insulated space between the inner and outer walls of the refrigerator.

Upon rotation of the mold 12 about its vertical axis as represented by the shaft 11, ice pieces are centrifugally discharged from the mold and for the purpose of confining these ice pieces to the neighborhood of the mold and for directing their discharge into the receptacle 6 positioned below the mold, the mold is surrounded by a housing 30 including an annular side wall most of which is positioned close enough to the outer edge of the mold 12 as represented by the mold strengthening skirt 32 so that the ice pieces cannot fall between these portions of the wall 31 and the mold. At one point about the periphery of the mold, a housing side wall portion 33 is spaced a sufiicient distance from the edge 32 of the mold so that ice pieces released from the mold can drop through the opening 34 formed by the side wall portion 33 and fall into the receptacle 6. In order that cold air from the evaporator will circulate about the contents of the mold 12, air passages 29 are provided in the housing wall'31.

When the receptacle 6 becomes filled with ice pieces indicated by numeral 35 so that it is desirable to stop the automatic operation of the ice maker, there is provided an ice level sensing means operative to perform its sensing function during rotation of the shaft 11. This sensing means 37 is mounted on the lower end of the shaft 11 and comprises a cup-shaped member 38 having a substantially hemispherical shape and including a hub 39 slidably mounted on the shaft 11 and secured thereto by a centrifugal mechanism including opposed pairs of pivoted levers 40 connected at one end to the hub 39 and at the other end to an arm 41 secured to the shaft 11. By this arrangement, the cup member 38 is free to move between a lowered or normal position and a raised position during rotation of the shaft, movement to the raised position being effected by the centrifugal forces on the pivot levers 40. Whenever the motor is energized for discharge of ice pieces by rotation of the mold 12, the cup member 38 will be lifted during the period that the ice pieces are being discharged in the receptacle 6. When the motor 10 is de-energized the cup is free to drop to its lower position unless prevented from doing so by the accumulation of ice pieces in the receptacle 6.

For the purpose of controlling the automatic operation of the ice maker through the filling and ice harvesting cycles and for stopping the operation of the ice maker when-sufficient ice is collected in the receptacle 6, there is provided electrical control circuitry including a mold operated switch 43 for controlling the operation of the solenoid valve 44 and an ice limit switch 45 designed to stop the operation of the ice maker when suflicient ice is accumulated in the receptacle 6.

The switch 43 is positioned below the ice mold 12 and includes a switch arm 46 adapted to be engaged by an annular flange 47 when the tray 12 is in its lower or filled position. The normally closed ice limit switch 45 is designed to be opened when the sensing member 38 -member 38 is in its elevated position.

is in its raised position and this is accomplished in the illustrated embodiment of the invention by means of cam surfaces 49 provided on the upper end of the pivot levers 40 which are designed to raise the switch member 50 and open the switch contacts 51 and 52 Whenever the Normally the switch member 50 is biased downwardly so that the contacts 51 and 52 are closed and biased closed by means of a spring 53 carried on the shaft 11 above the member 50.

For energizing the motor 10 upon the freezing of a charge of water in the mold 12, there is provided a thermostat switch 54 also supported on the housing 7. While any suitable thermostatic switch may be used, there is illustrated the usual bulb and bellows type including a sensing bulb or tube 55 positioned closely adjacent the bottom walls of the cavities 22. In this position the sensing bulb or tube 55 is protected or shielded from the circulating cold air passing through air passages 29 and the upper portion of the housing 30 above the mold 12 by the mold and also by the upwardly extending walls 5'6 provided as part of the support 7. When the switch 54 senses a below freezing temperature indicating that the water contained in the mold has frozen, the control circuitry is designed to energize the motor 10 and initiate the ice harvesting cycle.

For a more detailed understanding of the control circuitry and the manner in which it automatically controls the operation of the ice maker, reference is made to FIG- URE 4 of the drawing. As illustrated, the mold operated switch 43 is a double pole switch movable to a first position when the mold is empty and to a second position when the mold is full while the thermostat switch 54 is also a double pole switch movable either to a warm or to cold position as determined by the temperature adjacent the bottom of the ice mold 12. The control circuitry includes a first circuit across the

supply lines

57, 58 comprising the switch 43 in its empty position, the solenoid valve 44, the centrifugal ice limit switch 45 and the thermostat switch in its warm position for controlling the energization of the solenoid valve 44. A second circuit for energizing the motor 10 comprises the mold switch 43 in its full position, the motor 10 and the thermostatic switch in its cold position.

Assuming that a charge of water has just been introduced into the ice cavities 22, the thermostat 54' will sense the warm temperature of the water in the mold and the thermostat switch will therefore be in its warm position and as the motor 10 is not energized, the centrifugal ice limit switch 45 will be closed. The mold switch however will be in its full position so that the first circuit including the solenoid valve 44 will be open. Sub-freezing air circulated through the housing 30 and in contact with the contents of the mold 12 will gradually cause the Water contained therein to freeze. When the freezing is complete so that the sensing bulb or tube 55 senses a sub-freezing temperature, the thermostat switch 54 will move to its. cold position and, as the mold switch is in its full position, motor 10 will be energized. Rotation of the mold 12 centrifugally discharges the ice pieces from the mold for discharge through the opening 34 into the receptacle 6. As soon as the. ice pieces have been discharged, the mold will be raised by spring 21 to move switch 43 to its empty position. During rotation of the mold the centrifugal switch 45 will be opened and in the event the ice accumulated in the receptacle 6 is suificient to prevent the feeler cup member 38 from returning to its lower position, this switch 45 will be maintained in its open position thereby preventing subsequent energization of the solenoid valve to introduce another charge of Water even though the mold switch is in its empty position. In the event that the amount of ice in the receptacle 6 is insufficient to prevent cup member from dropping and again closing switch 45 as soon as the ice pieces have been discharged from the mold 12,

switches 4-3 and 45 will both be conditioned to energize the solenoid valve upon movement of the thermostat switch to its warm position. This operation of the thermostat switch 54 following a harvesting cycle may take place due to the heat of the motor which is adjacent the sensing bulb 55 or it can be accelerated by providing a heater 59 in heating position relative to bulb 55' connected across the

lines

57, 53 whenever the thermostat switch is in its cold position. The heater 59 is designed to accelerate the warming of the sensing bulb 55 which will cause the thermostat switch to move to its warm position. Upon movement of the switch 54 to its warm position, the solenoid valve or first circuit is energized and the valve will remain open to discharge water into the mold until the mold switch moves to its full position. Thereafter, with the tray switch in its full position, the motor circuit will again be energized whenever the thermostat switch moves to its cold position as a result of freezing of the water in the mold cavities 22. The ice maker is then conditioned for the next harvesting cycle.

While there has been shown and described a particular embodiment of the present invention, it will be obvi us to those skilled in the art that various changes and modi Acations may be made therein without departing from the invention and it is intended by the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An automatic ice maker comprising a support;

a drive means including a motor and a vertical drive shaft mounted on said support,

an annular ice mold having a plurality of cavities from which ice pieces formed therein will be centrifugally discharged upon rotation of said tray about a vertical axis,

means for supporting said mold on said shaft for rotation therewith and for limited vertical sliding movement of said mold on said shaft between an upper position when empty and a lower position when filled with Water,

an ice receptacle positioned below said ice tray,

sensing means for sensing the level of ice in said receptacle, said sensing means comprising a feeler member and centrifugal mechanism securing said feeler member to the lower end of said shaft for rotation thereof with said shaft,

said centrifugal mechanism being adapted to raise said feeler member from a normal lower position to a raised position during rotation of said shaft,

water supply means including a solenoid valve,

a thermal switch movable to a cold position in response to a freezing temperature of said ice mold and a warm position in response to an elevated temperature of said mold,

a mold operated switch movable to a first position when said mold is filled and a second position when said mold is empty,

a normally closed ice level switch adapted to be opened when said feeler member is in its raised position,

a solenoid valve control circuit comprising said mold operated switch in its first position, said ice level switch and said thermal switch in its warm position for opening said valve when said mold is empty and at an elevated temperature,

a motor circuit including said mold operated switch in its second position and said thermal switch in its cold position for energizing said motor when said mold is filled and at a freezing temperature.

2. An automatic ice maker comprising a support;

a drive means including a motor and a vertical drive shaft mounted on said support;

an annular ice mold having a plurality of radially extending cavities from which the ice pieces formed therein will be centrifugally discharged upon rotation of said tray about a vertical axis,

an ice receptacle pos 'oned below said ice tray,

sensing means for sensing the level of ice in said receptacle, said sensing means comprising a cup-shaped feeier member and centrifugal mechanism securing said feeler member to the lower end of said shaft for rotation thereof with said shaft,

said centr ugal mechanism being adapted to raise said feeler memoer from a normal low position to a raised position during rotation of said shaft,

a housing enclosing said mold and i eluding a wall portion spaced from said tray to define an opening between said housing and said tray of a size sulficient to permit ice pieces discharged from said mold to drop into said receptacle, the remaining portions of said housing being arranged to confine released ice pieces and direct them to said opening,

water supply means including a solenoid valve,

a thermal switch movable to a cold position in response to a freezing te r perature of said ice mold and a warm position in response to an elevated temperature of said mold,

3. An automatic ice maker comprising;

a horizontally disposed ice mold from. which ice pieces formed therein are centrifugally discharged upon rotation of said mold about a vertical axis,

a receptacle for receiving ice pieces discharged from said mold,

drive means for rotating said mold,

ice level sensing means including a member movable between a normal position extending into said receptacle and an elevated position and adapted to stop operation of said ice maker when the accumulation of ice in said receptacle maintains said member in an elevated position,

and centrifugal means driven by said drive means for raising said member during rotation of said ice mold.

References Cited in the file of this patent UNITED STATES PATENTS

Claims

3. AN AUTOMATIC ICE MAKER COMPRISING; A HORIZONTALLY DISPOSED ICE MOLD FROM WHICH ICE PIECED FORMED THEREIN ARE CENTRIFUGALLY DISCHARGED UPON ROTATION OF SAID MOLD ABOUT A VERTICAL AXIS, A RECEPTACLE FOR RECEIVING ICE PIECES DISCHARGED FROM SAID MOLD, DRIVE MEANS FOR ROTATING SAID MOLD, ICE LEVEL SENSING MEANS INCLUDING A MEMBER MOVABLE BETWEEN A NORMAL POSITION EXTENDING INTO SAID RECEPTACLE AND AN ELEVATED POSITION AND ADAPTED TO STOP OPERATION OF SAID ICE MAKER WHEN THE ACCUMULATION OF ICE IN SAID RECEPTACLE MAINTAINS SAID MEMBER IN AN ELEVATED POSITION, AND CENTRIFUGAL MEANS DRIVEN BY SAID DRIVE MEANS FOR RAISING SAID MEMBER DURING ROTATION OF SAID ICE MOLD.