US3009330A - Automatic ice maker control means - Google Patents

Description

Nov. 21, 1961 H. P. HARLE AUTOMATIC ICE MAKER CONTROL MEANS 2 Sheets-Sheet 1 Filed Sept. 14, 1960 INVEN TOR. HAROLD F'. HARLE H 15 ATTORNEY Nov. 21, 1961 H. P. HARLE AUTOMATIC ICE MAKER CONTROL MEANS 2 Sheets-Sheet 2 F i G. 3

Filed Sept. 14, 1960 FIGZ INVENTOR.

a HAROLD P. HARLE HIS ATTORNEY Patented Nov. 21, 1961 free 3,009,330 AUTOMATIC ICE MAKER CONTROL MEANS Harold P. Harte, Louisville, Ky., assignor to General Electric Company, a corporation of New York Filed Sept. 14, 1960, Ser. No. 55,954 2 (Ilaiins. (til. 62-437) 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 particularly 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 I. Lowenthal 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 eifecting 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;

FIGS 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 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 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 dividers 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.

In orderto release ice pieces formed in the compartments 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.

U When this heating element is energized, the mold, in-

cluding 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 surfaces and the ice pieces. However, since the movable dividers 12 are composed of a material of lower heat conductivity than the mold, there isinsufiicient 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 remain frozen to the low heat conductivity material for a longer period of time than to the directly heated mold, in order to morepositively 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 movable dividers 12 have fins 24 along both sides of the rear edges thereof, that is along the edges adjacent the shaft 18, 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 from the mold by rotation of the shaft 18 to a discharge position as shown in FIG. 2 in which the ice pieces come into contact with a plurality of spaced bumpers 26 suitably supported along the side wall 8 of the mold. As will be seen in FIG. 1 of the drawing these bumpers are opposite the fixed, dividers l0 and are wide, enough to overlap thecompartments ll on each side of the fixed dividers. When the ice pieces contact the surfaces of bumpers, movement of the ice pieces is stopped and the continued movement of the dividers causes theice 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 housingZS secured to one end of the mold 5. The power mechanism includes a motor 29 diagrammatically illustrated in FIG. of the drawing, the motor and a suitable speed 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. 2 is connected to the end of the shaft 18 extending into into the housing and an arm 34- connected to the drive shaft 35 forming part of the drive mechanism 36 provides means for connecting the motor to the shaft to rotate the shaft 18 after certain control switching functions have been effected by the motor. To this end, the arm 34 is arranged for delayed engagement with the pawl 37 after initial 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 rotating 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.

The illustrated water supply means, which is more fully described and claimed in my copending application S.N. 25,432 filed April 29, 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 to the various compartments 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 actuated switch such as a bellows operated single pole double throw switch 44 diagrammatically illustrated in FIG. 5 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 sensing 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 along 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 52 engaging the cam 51, the cam 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 a pin 55 carried on the actuating lever 53 as shown in FIG. 3 of the drawing.

In accordance with the present invention there is provided an improved 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 capillary sensing bulb reaches about 2025 F. indicating the complete freezing of the water in the mold, the switch arm 56 of the single pole double throw switch 44 moves into contact with the cold switch contact 57. This completes a first motor energizing circuit between the supply conductors 58, 59 through the cold contact 57 of the switch 44 and a first motor operated switch 60 which is normally closed and which is operated by a cam 61 driven by the motor 29 through the shaft 35. Energizetion of the motor 29 causes rotation of both of the cams 51 and 61 whereby the cam 51 releases the feeler arm so that it is free to drop to its lowered position after which the cam 61 opens the motor operated switch 60 to break the first motor energizing circuit. In the event that there is sufiicient ice in the receptacle to prevent the feeler arm from dropping to its lowered position thereby closing switch 52, the operation of the ice maker is interrupted by the opening of the switch 60 and this condition will continue until enough ice has been removed from the receptacle so that the feeler arm can fall to its lower switch operating position. After removal of this ice or if the amount of ice accumulated in the receptacle 3 was insuflicient to prevent the feeler arm 50 from reaching its lowermost position, the closing of switch 52 completes a second motor energizing circuit through switch 52 and the cold contact 57 of switch 44 so that the motor continues to be energized through this second circuit after switch 60 is opened. The establishment of the second motor energizing circuit causes the cam 61 to close a heater switch 63 for energizing the heater 23 in order to melt the bond between the ice piece and the mold.

After cam 61 has rotated to the point where the heater switch 63 closes to energize the heater 23, the drive arm 34 is designed to engage the pawl 37 for rotation of the shaft 18 as soon as the bond between the ice pieces and the mold is thawed or broken. In the meantime, the motor stalls although it continues to be energized through the second motor energizing circuit including switch 52 and the cold contact 57 of switch 44.

When this ice bond is broken, the motor again operates so that 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. Release of pawl 37 then permits the dividers to return to the mold. During this time the mold is warmed by the heater 23 to an above freezing temperature. As the temperature of the sensing bulb 47 lags the mold temperature due to the insulating effect of housing 46, the switch 44 is designed so that when the sensing bulb temperature is about 3035 F., the switch arm 56 moves into engagement with the warm contact 65 whereby a third motor energizing circuit is established through the heater switch 63 and the warm contact 65 of the switch 44. One purpose of this third motor energizing circuit is to continue the energization of the motor 29 during the latter stages of the ice making cycle, that is after the cam 51 has rotated to a position such that it raises the feeler arm 50 to its elevated position thus opening the switch 52 to break the second motor energizing circuit. By this circuitry, the ice maker operation will be interrupted at this point until such time as the switch 44 does trip to its warm position or more specifically away from its cold position before a new charge of water is introduced into the mold. In other words, after the level switch 52 is opened the motor can only be energized by control switch 44 in its warm position. This feature prevents repeated cycling of the ice maker if the control 44 due to any malfunction remains in its cold position.

Continued rotation of the cam 61 thereafter closes a valve energizing switch 66 to energize and open the solenoid valve 42, the operation portion of the cam surface indicated by the numeral 68 being designed to time the open period in order to introduce a controlled quantity of water into the mold.

When the earns 51 and 61 have completed their rotation through one revolution, the cam 51 has returned the feeler arm to its uppermost position while the cam 61 has returned the switches 60, 63 and 66 to their normal or starting positions, the opening of the heater switch 63 causing both the motor and the heater 23 to be deenergized. The control and power mechanism is thereby set for the next operating cycle of the ice maker when the switch arm 56 of switch 44 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, and it is intended by the appended claims to cover all such changes and modifications that 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 level detecting position within said receptacle for measuring the level of ice therein, feeler arm actuating means operated by said motor for releasing said arm for movement to said level detecting 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, a control 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 normally closed motor-operated motor switch and a normally open motor-operated heater switch, said motor switch and said control switch being series connected when said control switch is in its cold position to complete a first circuit for energizing said motor to release said feeler arm for movement to a position closing said feeler arm switch to thereby establish a second motor energizing circuit through said feeler arm switch and said control switch in its cold position, continued energization of said motor opening said motor switch to break said first circuit and closing said heater switch, said heater switch and said control switch in its warm position being series connected to complete a third motor energizing circuit when said mold attains an above-freezing temperature to complete the ice making cycle and return said feeler arm actuating means to its normal position whereby said feeler arm switch is opened to interrupt said second circuit.

2. 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 level detecting position within said receptacle for measuring the level of ice therein, feeler arm actuating means operated by said motor for releasing said arm for movement to said level detecting 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, a control 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 normally closed motor-operated motor switch, and a normally open motor-operated heater switch, said motor switch and said control switch being series connected when said control switch is in its cold position to complete a first circuit for energizing said motor to release said feeler arm for movement to a position closing said feeler arm switch to thereby establish a second motor energizing circuit through said feeler arm switch and said control switch in its cold position, continued energization of said motor opening said motor switch to break said first circuit and thereafter closing said heater switch to thaw the bond between said ice and said mold, said motor being stalled while energized by said second circuit while the bond between the ice and mold is being thawed, said heater switch and said control switch in its warm position being series connected to complete a third motor energizing circuit when said mold attains an abovefreezing temperature after removal of the ice therefrom to complete the ice making cycle, to return said feeler anm actuating means to its normal position whereby said feeler arm switch is opened to interrupt said second circuit, said feeler arm switch being arranged to remain open if said feeler arm is held in an elevated position by the level of ice in said receptacle whereby opening of said motor switch to break said first circuit stops the operation of said ice maker before closing of said heater switch.

References Cited in the file of this patent UNITED STATES PATENTS 2,744,390 Partsch May 8, 1956 2,778,198 Heath Jan. 22, 1957 2,796,741 Barton June 25, 1957 2,799,144 Barton July 16, 1957 2,955,442 Loewenthal Oct. 11, 1960- 2,987,895 Loewenthal June 13, 1961

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