US3009329A - Automatic ice maker control means - Google Patents

Description

Nov. 21, 1961 H. P. HARLE AUTOMATIC IC E MAKER CONTROL MEANS 2 Sheets-Sheet 1 Filed Sept. 14, 1960 INVENTOR.

P. HARLE HAROLD HIS ATTORNEY Nov. 21, 1961 H. P. HARLE AUTOMATIC ICE MAKER CONTROL MEANS Filed Sept. 14, 1960' FIQZ F'iCzS ME TL Y m E Vm N N R o P T T n A m W w M H V. B u

z 5 m as Patented Nov 21, 1961 3,009,329 AUTOMATIC ICE MAKER CONTROL MEANS Harold P. Harle, Louisville, Ky., assignor to General Electric Company, a corporation of New York Filed Sept. 14, 1960, Ser. No. 55,953 2 Claims. (Cl. 62-137) The present invention relates to an automatic ice maker and is more particularly concerned with an improved control means for an ice maker of the type adapted to be incorporated in a domestic or household refrigerator.

The invention relates particualrly to the general type of ice maker including a mold in which a charge of water is frozen, means for heating the mold to release the ice pieces formed therein, means for removing ice pieces formed in the mold comprising one or more pivoting transfer elements which are frozen into engagement with the ice pieces during each freezing cycle and are movable from their normal positions within the mold to an ice piece discharge position outside the mold and water supply means for thereafter introducing another charge of water into the mold. An ice maker of this type in which movable dividers or partitions serve as transfer elements for harvesting the ice pieces is described and claimed in the copending application Serial No. 813,790 (now Patent 2,970,453) filed May 18, 1959, in the names of Harold P. Harle, Stephen Balogh and Henry J. Loewenthal and assigned to the same assignee as the present invention.

The present invention has as its principal object the provision of an improved control means for effecting the automatic operation of an ice maker.

Another and more specific object of the invention is to provide an automatic ice maker of this type including improved control means for stopping the operation of the ice maker when the required quantity of ice has been manufactured.

Further objects and advantages of the invention will become apparent from the following description, reference being made to the accompanying drawing in which:

FIG. 1 is an elevational view, partly in section, of an ice maker including an embodiment of the present invention;

FIG. 2 is a sectional view of the ice maker along line 2-2 of FIG. 1; Y

FIG. 3 is a sectional view of the ice maker along line 3-3 of FIG. 1;

FIG. 4 is a sectional view of the ice mold taken generally along line 44 of FIG. 1 but showing the movable dividers in a discharge position; and

FIG. 5 is a wiring diagram of the improved electrical control system employed for the automatic operation of the ice maker in accordance with the present invention.

With reference to FIG. 1 of the drawing, there is illustrated an ice maker designed to be suspended from the top wall 1 of the low temperature or freezing compartment 2 of a household refrigerator. The contents of the compartment 2 including the ice maker are maintained at the below freezing temperatures by air circulated over a low temperature evaporator (not shown) so that the ice maker can be mounted in the compartment out of direct contact with an evaporator unit. Also positioned within the compartment and below the ice maker is an ice receptacle or bin '3 in which ice pieces 4 discharged from the ice maker are stored at below freezing temperatures.

Referring now to FIGS, 1 and 2 of the drawing, the ice maker includes an elongated ice mold 5 comprising end walls 7 and side walls 8 and 9 forming a substantially rectangular mold cavity which is divided into a plurality of sections by fixed, full width dividers or partitions 10 extending transversely of the mold cavity. Each of these sections is in turn divided into adjacent interconnected compartments 11 by movable dividers 12 arranged between the fixed dividers. The mold proper including the end walls 7, the side walls 8 and 9, the fixed dividers 10, and a bottom wall 14 are composed of metal and preferably comprise a unitary die cast structure.

The movable dividers 12 which function as transfer elements for removing ice pieces from the mold are composed of a low heat conducting flexible material such'as a plastic material, thin stainless steel or the like and are each mounted on a shaft 18 rotatably supported above the vertical mold side Wall 8. In order that the movable divider 12 can pivot about the axis of the shaft 18 from a position within the mold as illustrated in FIG. 1 to a discharge position along one side of the mold as illustrated in FIG. 4, the mold side wall 9 opposite the shaft 18 slopes outwardly and is of a generally concave configuration while the cooperating side edge 19 of each of the movable dividers is similarly shaped. To provide for the flow of water from one compartment to another during filling of the mold cavity, each of the fixed dividers 10 includes a slot 20 adjacent the side wall 9 while the movable dividers 12 have their upper edge portions 21 terminating short of the side wall 9 to provide a channel or spacing similar to that provided by the slots 20. i

In order to release ice pieces formed in the compart: ments 11 from the mold walls, there is provided an electric heating element 23 extending in the form of a loop around the bottom wall 14 below the side walls 8 and 9. When the heating element is energized, the mold, including its bottom wall 14, the end walls 6 and 7 and the side walls 8 and 9 as well as the fixed partitions 10, becomes sufficiently warm to melt the bond between the mold sur: faces and the ice pieces. However, since the movable dividers 12 are composed of a material of lower heat conductivity than the mold, there is insufiicient warming of these members to melt the ice bond. These movable dividers, upon rotation out of the mold, then serve as transfer elements by means of which ice pieces adhering thereto are removed from the mold. While there is a natural tendency for the pieces to re.- main frozen to the low heat conductivity material for a longer period of time than to the directly heated mold, in order to more positively assure transportation of the ice pieces from the mold and over the mold side wall 8 during pivotal movement of the movable elements" 12, these elements are preferably also provided with additional means for anchoring the ice pieces to the dividers. In the illustrated embodiment of the invention, the IllOVr able dividers 12 have fins 24 along both sides of the rear edges thereof, that is along the edges adjacent the shaft 13, and notches 25 in the opposite edges. Once the bond between the ice mold proper and the ice pieces has been broken or thawed, the movable dividers 12 can be pivoted upwardly and outwardly fromthe mold by rotation of the shaft 18 to a discharge position as shown in FIG. 2 in which the ice pieces come into con; tact with the plurality of speed bumpers 26 suitably sup.- ported along the side wall 8 of the mold. As willbe 'seen in FIG. 1 of the drawing these bumpers are opposite the fixed dividers 10 and are wide enough to overlap the compartments 11 on each side of the fixed dividers. w en the ice pieces contact the surfaces of bumpers, movement of the ice pieces is stopped and the continued movement of the dividers causes the ice pieces to peel away from the dividers and drop into the receptacle 3 provided below the mold. I

Control and power mechanism for effecting and controlling the operation of the ice maker is generally housed in a housing 28 secured to one end ofthe mold 5. The power mechanism includes a motor 29 diagrammatically illustrated in FIG. 4 of the drawing, the motor and a suitable specd reducing gear train forming a drive mechanism generally shown in broken lines and indicated by the numeral 30 in FIG. 1 of the drawing. The shaft 18 is rotatably mounted in a bearing 31 adjacent the mold end wall 7 and a bearing (not shown) in the front wall 32 of the housing. A pawl assembly 33 shown in FIG. 3 is connected to the end of the shaft 18 extending into the housing and an arm 34 connected to the drive shaft 35 forming part of the drive mechanism 30 provides means for connecting the motor to the shaft to rotate the shaft 18 after certain switching functions are effected by operation of the motor. To this end, the arm 34 is adapted for delayed engagement of the pawl 37 after energization of the motor. The pawl 37 is pivotally supported on that assembly as illustrated in FIG. 2 of the drawing in such a position that after further rotation of the shaft 18 through a predetermined number of degrees, a projection 38 on the wall 32 causes disengagement of the pawl from the arm and allows the motor to continue rotation in the same direction while a return spring 40 on shaft 18 causes the shaft to rotate in the opposite direction and return the dividers to the mold. v The illustrated water supply means, which is more fully described and claimed in my copending application S.N. 25,432, filed April 28, 1960, and assigned to the same assignee as the present invention, includes a filler tube 41 connected through a normally closed solenoid valve 42 to a suitable source of water supply. When the solenoid valve is energized to open the valve, water is supplied to the mold from the outlet end of the tube 41 this charge of water flowing downwardly into the mold over a baffle 43 supported on the mold side wall 9. The water thus introduced into the mold flows from compartment to compartment through the slots 20 and around the dividers 12.

In order to initiate the ice harvesting cycle as soon as the water introduced into the mold has frozen, there is provided a motor control circuit including a thermal switch such as a bellows operated single pole double throw switch 44 diagrammatically illustrated in FIG. and generally housed within the housing 28. The sensing bulb component of the switch, in the form of a capillary tube, extends through the housing wall 32, through a plastic housing 45 along one side of the mold and then downwardly into a plastic housing 46 below one of the movable dividers 12 which is shortened to provide space for the housing. In this position of the end 47 of the capillary tube, the switch 44 is responsive to the temperature of the mold adjacent one of the movable dividers.

After a number of ice making cycles, the receptacle 3 becomes filled with ice pieces. In order to stop the ice making operation when this occurs, the ice maker includes a U-shaped feeler arm 50 which is pivotally mounted at each end long the side 9 of the ice mold for movement between an elevated position out of the receptacle as shown in FIG. 1 and a lowered position within the receptacle. Normally, that is during the freezing step of the ice making cycle, this arm is held in its elevated position by a motor driven cam 51. This cam is so designed that during each ice harvesting cycle, the cam 51 releases the arm 50 so that it can drop to its lowered position within the receptacle. If this drop to the lowered position is interrupted by contact of the arm with the accumulated ice in the receptacle, a normally open switch 52 operated by the feeler arm 50 remains in an open position to interrupt the ice making cycle and stop the operation of the ice maker. To obtain this operation, the feeler arm includes within the housing 28 an extension or actuating lever 53, the cam 51 in turn being mounted on the shaft 35 driven by the motor 29. The normally open switch 52 is designed to be closed when the feeler arm is in its lowered position by means of a pin 55 carried on the lever 53 as shown in FIG. 3 of the drawing.

In accordance with the present invention, there is provided a simple low cost control circuitry for the automatic control of an ice maker of this type through a complete ice making cycle. This improved circuitry and control means will be described in connection with the following consideration of the operation of the ice maker.

When the temperature sensed by the end 47 of the sensing bulb is in the neighborhood of 2025 F. assuring the complete freezing of the water in the mold, the switch arm 56 of the single pole double throw thermal switch 44 is adapted to move into contact with the cold switch contact 57. This completes a first motor energizing circuit between the supply conductors 58, 59, which circuit includes a first normally closed control switch 60, the cold contact 57 of thermal switch 44 and a second normally closed control switch 61, the two switches being operated by a switch cam 62 driven by the motor 2? through the shaft 35. Contact of the switch arm 56 with the cold contact 57 of the thermal switch also completes a heater energizing circuit through the switch 60 and the cold contact 57 of switch 44. Operation of the motor 29 then causes rotation of both of the cams 51 and 52 which are so constructed and arranged that shortly after initial energization of the motor, cam 51 releases the feeler arm so that it is free to drop to its lowered position within the receptacle in which position the extension 53 of the feeler arm will close switch 52. In the event that there is sufiicient ice in the receptacle to prevent the feeler arm from dropping to its lower position and thereby closing switch 52, the operation of the ice maker will shortly be interrupted by the opening of switch 60 and this condition will continue until enough ice has been removed from receptacle so that the feeler arm can fall to its lower switch closing position. After removal of the ice or if the amount of ice accumulated in the receptacle 3 is insufiicient to prevent the feeler arm 50 from reaching its lowermost position, the closing of switch 52 establishes a second heater energizing circuit including the switch 52 and the cold contact 57 of control switch 44 and also establishes a second motor energizing circuit comprising the feeler arm switch 52, the cold contact 57 of switch 44 and the motor operated switch 61.

Whether or not the switch 52 is closed to establish the second motor energizing circuit, the motor will continue to operate under the first energizing circuit until, after a few degrees of rotation of cam 62, the cam opens the switch 60. At this point the ice maker operation is interrupted unless the second motor energizing circuit has been completed through the feeler arm switch 52.

With the feeler arm in its lowermost position, the motor continues to operate through the second energizing circuit including the feeler arm switch 52 whereby the cam 62 again closes the first control switch 60 and also closes a third control switch 64 to establish a third motor energizing circuit through switch 60, the switch 64 and switch 61 bypassing the cold contact 57 of switch 44 through the switch 64 connected in parallel therewith. The closing of switch 64 also establishes a third heater energizing circuit which includes the switch 60 and the switch 64 and which also bypasses the cold contact 57 of the switch 44. These third circuits also parallel the feeler arm switch portion of the second circuits and the cam 51 is designed to raise the feeler arm and open the second circuits after closing of switch 64 and preferably before operation of the ice transfer means.

At this point in the operation of the control means, the drive arm 34 is designed to engage pawl 37 for the purpose of rotating the shaft 18 and transfer the ice pieces out of the mold and into engagement with the bumpers 26 as soon as the bond between the ice pieces and the mold is broken or thawed by the heater 23. If the heater has not been energized for a period of time sufiicient to thaw this bond, the motor 29 will stall although it will continue to be energized through the third motor energizing circuit and, if the feeler arm switch is still closed, also through the second motor energizing circuit.

As soon as the bond between the ice and the mold is broken, the motor again rotates and during the suc ceeding portion of the ice making cycle, the dividers and the ice pieces 4 adhering thereto are rotated out of the mold into a position in which the ice pieces 4 contact the bumpers 26 and are peeled from the dividers 12' for discharge into the receptacle 3.

After the ice pieces are removed from contact with the mold walls during the harvesting portion of the ice making cycle, the temperature of mold, which is continually being warmed by the heater 23, continues to rise. When the temperature of the sensing means. 47 which lags the, mold temperature due to the insulating eifect of housing 46' attains an elevated temperature of for example 30 -35 the switch arm 56 trips into engagement with the warm contact 67 to establish a fourth motor energizing circuit including switches 60 and 64 and the warm contact 67 of switch 44.

Further rotation of the switch cam 62 causes switch 61 to open thereby breaking the third motor energizing circuit and leaving the motor energized solely by the fourth energizing circuit including the switch 64 so that upon subsequent opening of the switch 64 to restore the control switches to their normal or original positions, the motor will be de-energized. Finally, and before the motor is de-energized, cam 62 closes a valve switch 68 to open the solenoid valve 42, this final portion of the cam surface closing the valve switch being designed to time the valve operating period in order to introduce a controlled quantity of water in the mold. Opening of switch 68 conditions the control and power mechanism for the next operating cycle of the ice maker which is initiated when the switch arm 56 again engages contact 57.

While there has been shown and described a particular embodiment of the present invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention 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. In an automatic ice maker comprising a mold in which water is frozen into ice, a storage receptacle, heating means for heating said mold to release the ice formed therein, transfer means for transferring the released ice from said mold to said receptacle, a motor for operating said transfer means, a feeler arm normally held in a position above said receptacle and movable to a lowered position within said receptacle for measuring the level of ice therein, feeler arm actuating means operated by said motor for releasing said arm upon initial energization of said motor to permit movement of said arm to said lowered position; electrical control means for controlling the automatic operation of said ice maker through an ice making cycle including successive freezing, releasing and transferring steps and for stopping operation of said ice maker upon the accumulation of ice in said receptacle comprising a normally open feeler arm switch adapted to be closed by said feeler arm in its lowered position; a thermal switch movable to a cold position in response to a freezing temperature of said mold and to a warm position in response to an elevated temperature of said mold; a plurality of control switches; switch operating means driven by said motor for operating said control switches through one complete cycle; a first motor circuit including a first normally closed control switch and said thermal switch for initially energizing said motor when said thermal switch is in its cold position; a first heater circuit including said first control switch, said thermal switch in its cold position and a second normally closed control switch for energizing said heater; said feeler arm switch being in parallel circuit connection with said first control switch whereby closing of said feeler arm switch by said feeler arm will complete second motor and heater circuits bypassing said first control switch when said feeler arm moves to its lower position; said switch operating means being arranged to open said first control switch after release of said feeler arm whereby said motor and heater are de-energized and the operation of said ice maker interrupted if said feeler arm is prevented from moving to its lower position by the accumulation of ice in said recept-acle; energization of said motor by said second motor circuit closing said first control switch and closing a third normally open control switch to establish a third motor circuit bypassing said thermal switch and said feeler arm switch and including said first, second and third control switches and a thirdheater circuit bypassing said thermal switch and said feeler arm switch and including said first and third control switches; said feeler arm actuating means being arranged to raise said arm and open said feeler arm switch after said third circuits have been established, a fourth motor circuit comprising said first and third control switches and said thermal switch in its warm position for energizing said motor, said switch operating means being arranged to open said second control switch after closing of said third control switch to break said third motor circuit and said third heater circuit and condition said control means for stopping said ice maker when said switch operating means completes a cycle of operation to open said third control switch.

2. In an automatic ice maker comprising a mold in which a charge of water is frozen into ice, a storage receptacle, heating means for heating said mold to release the ice formed therein, transfer means for transferring the released ice from said mold to said receptacle, a motor for operating said transfer means, a feeler arm normally held in a position above said receptacle and movable to a lowered position within said receptacle for measuring the level of ice therein, feeler arm actuating means operated by said motor for releasing said arm upon initial energization of said motor to permit movement of said arm to said lowered position; electrical control means for controlling the automatic operation of said ice maker through an ice making cycle including successive freezing, releasing and transferring steps and for stopping the operation of said ice maker upon the accumulation of ice in said receptacle comprising a normally open feeler arm switch adapted to be closed by said feeler arm in its lowered position, a thermal switch movable to a cold position in response to a freezing temperature of said mold and to a warm position in response to an elevated temperature of said mold, a plurality of control switches, said switches being connected to form a first motor circuit including a first normally closed control switch and said thermal switch in its cold position, a first heater circuit including said first control switch, said thermal switch in a cold position and a second normally closed control switch for energizing said heater, a second motor energizing circuit including said feeler arm switch, said second control switch and said thermal switch in its cold position, a second heater circuit including said rfeeler arm switch and said thermal switch in its cold position,

a third motor energizing circuit including said first, second and a third control switch, a third heater circuit including said first and third control switches, a fourth motor circuit comprising said first and third control switches and said thermal switch in its warm position and motor driven switch actuating means for operating said control switches, said switch actuating means being coordinated in its operation with said feeler arm actuating means whereby upon movement of said thermal switch to its cold positionenergizes said motor through said thermal switch and said first normally closed control switch and to energize said heater, to thereby release said feeler arm for movement to its lowered position to close said feeler arm switch and thereafter to open said first control switch to interrupt the operation of said ice maker if said feeler arm is prevented from moving to its lowered position by the accumulation of ice in said receptacle, said switch actuating means being arranged so that upon continued operation of said motor when said feeler arm switch is closed, said switch actuating means will first open said first control switch to break said first circuit and stop the operation of the ice maker if the feeler arm switch has not closed to complete said second circuit and thereafter to again close said first control switch and said third normally open switch to complete said third circuit for energizing said motor and said heater, said transfer means being adapted to be drivingly connected to said motor upon completion of said third circuits whereby said motor is stalled until the bond between the ice in the mold and the mold surfaces is broken, removal of the ice from the mold causing said thermal switch to move to its warm position to complete said fourth motor energizing cir- References Cited in the file of this patent UNITED STATES PATENTS Partsch May 8, 1956 Loewenthal Oct. 11, 1960

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