US 3014350 A
Abstract available in
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Description (OCR text may contain errors)
Dec. 26, 1961 H. P. HARLE AUTOMATIC ICE M 5 Sheets-Sheet 1 Filed April 28, 1960 INVENTOR.
P. HARLE HAROLD Hls ATTORNEY Dec. 26, 1961 H. P. HARLE AUTOMATIC ICE MAKER 3 Sheets-Sheet 2 Filed April 28, 1960 INVENTOR.
P. HARLE W HAROLD BY FIG.7 76 z/ H is ATTORNEY Dec. 26, 1961 H. P. HARLE AUTOMATIC ICE MAKER 5 Sheets-Sheet 3 Filed April 28, 1960 F I G. 4
HAROLD P.IHARLE BY Hi5 ATTORNEY States 3,014,350 AUTOMATIC ICE MAKER Harold P. Harle, Louisville, Ky., assignor to General Electric Company, a corporation of New York Filed Apr. 28, 1960, Ser. No. 25,298 2 Claims. (Cl. 62139) frozen, means for removing the ice pieces formed in the mold comprising a pivoting transfer element which is frozen into engagement with the ice piece during each freezing cycle and is movable from its normal position within the mold to an ice piece discharge position outside the mold and water supply means for 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 ice pieces is described and claimed in the copending application Serial No. 813,790 filed May 18, 1959, now Patent No. 2,970,453 granted February 7, 1961, in the names of Harold P. Harle, Stephen Balogh and Henry J. Loewenthal and assigned to the same assignee as the present invention.
Inthe operation of an ice maker of this type, an ice piece may occasionally become separated from its transfer element during the ice harvesting cycle and fall back into the mold. If this stray ice piece is in such a position within the mold that it prevents full return of the transfer element to its normal position within the mold, the ice maker is rendered inoperative.
The present invention has as its principal object the provision of means for preventing an ice piece present in the mold at the end of one ice making cycle from interfering with the automatic operation of the ice maker.
Another object, of the invention is to provide in an ice maker of the above type and control means for energizing the mold heater to melt any stray ice piece present in the mold and preventing return of the transfer element I to the mold.
Further objects and advantages of the invention will become apparent from the following description, reference being made to theaccompanying drawing in which:
FIG. 1 is an elevational view, partly in section, of an ice maker including an embodiment of the present invention; 1
FIG. 2 is a top view of the ice maker shown in FIG. 1; FIG. 3 is a vertical section of a portion of the, iee fmaker taken along line 3-3 of FIG. 2;
FIG. 4 is a vertical view of the ice mold component taken along line 4-4 of FIG. 2;
.FIG. 5 is another sectional view of the ice mold taken generally along line 5- 5 of FIG. 2 but showing the movablc dividers in a partially elevated position;
FIG. 6 is an operational viewof the mechanism particularly shown in FIG. 3; and
FIG. 7 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.
In FIG. 1 of the accompanying 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 below freezing temperatures by air blown over a low 1 temperatureevaporator (not shown) so that the. ice maker can be mounted in the compartmentindependently of any 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, 2 and 4, the ice maker includes an elongated or generally rectangular ice mold 5 comprising end walls 6 and 7 and side walls 8 and 9 forming a substantially rectangular mold cavity which is divided into a plurality of sections by fixed dividers or partitions 10 extending transversely of the mold cavity. Each of these sections is in turn divided into compartments 11 by movable dividers 12 arranged between each of the fixed dividers or partitions 10. The mold proper including the end walls 6 and 7, the side walls 8 and 9 and the bottom Wall 14 as well as the fixed dividers or partitions 10 preferably comprise a unitary structure in the form of a metal die casting, such as an aluminum die casting, which may also include a plurality of external fins 15 for better heat transfer between the cooled air cireulating within the compartment 2 and the mold body.
As illustrated in FIG. 5 of the drawing, the movable dividers 1'2 which are composed of a low heat conducting flexible material such as a plastic material, thin stainless steel or the like, are each secured to a frame member 17 which in turn is fixed to 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 illus trated in FIG. 2, the mold side wall 9 opposite the shaft '18 slopes outwardly and is of a generally concave configuration while the cooperating side edge 22 of each of the movable dividers is similarly shaped. To provide for the flow of water fromone compartment to another during filling of the mold cavity, each of the fixed dividers 10 includes a slot 23' adjacent the side Wall 9 while the movable dividers 12 have their upper edge portions 26 terminating short of the side wall 9 to provide a channel or spacing similar to that provided by the slots 23.
In order to release ice pieces formed in the compartments 11 from the mold walls, there is provided an elecwarming 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 are removed from the mold. In the illustrated ice maker, additional means for preventing warming of the movable dividers to a temperature which will cause meltalge of the bond between the ice pieces and these dividers is provided in the form of one or more projections maintaining most of the movable divider structure in spaced relationship with the walls of the mold. For example, a projection indicated by the numeral 28 in FIG. 5 spaces the bottom edge of the divider 12 from the bottom of the mold 14. This spacing of most of the bottom edge of the movable dividers away from the mold bottom also prevents water formed by the melting of the ice in contact with the mold bottom 14 from being drawn up between the ice pieces and the movable dividers by capillary action and thereby loosening the ice pieces from the dividers.
. 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 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 ele ments 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 60 along both of the rear edges thereof, that is along the edges adjacent the shaft 18 and notches 61 in the opposite edges. In addition one or more small holes 62 are provided in the bottom edge of the divider so that as water freezes into ice in the compartments 11, the ice pieces are anchored positively to the movable dividers 12 by the portions of the ice extending through the notches 61 and the holes 62 while the fins 60 provide additional surface for bonding between the ice pieces and the movable divider 12.
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. 4 in which the ice pieces come into contact with a plurality of spaced bumpers 30 suitably supported along the side wall 8 of the mold. As will be seen in FIG. 1 of the drawing these bumpers, which are opposite the fixed dividers 10, are wide enough to overlap the compartments 11 on each side of the fixed dividers. When the ice pieces contact the surfaces of bumpers 30, 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 normally drop into the receptacle 3 provided below the mold.
Control and power mechanism for effecting and controlling the operation of the ice maker is generally housed in a housing 35 secured to one end of the mold 5. The power mechanism includes a motor 36 diagrammatically illustrated in FIG. 7 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 37 in FIGS. 1 and 2 of the drawing. The shaft 18 is rotatably mounted in a bearing 38 adjacent the mold end wall 7 and a bearing 39 in the front wall 40 of the housing 35. A pawl and cam assembly 42 is connected to the end of the shaft 18 extending into the housing 35 and an arm 44 connected to the drive shaft 45 forming part of the drive mechanism 37 provides means for connecting the motor to the shaft and rotating the shaft 18 upon operation of the motor 36. To this end, the arm 44 is adapted to engage the pawl 47 forming part of the pawl and cam assembly 42 during initial operation of the motor. The pawl 47 is pivotally supported on that assembly as illustrated in FIGS. 3 and 6 of the drawing in such a position that after rotation of the cam assembly 42 through a predetermined number of degrees, a projection 48 on the wall 40 causes disengagement of the pawl from the arm and allows the motor to continue rotating in the same direction while a return spring 50 causes the shaft 18 to rotate in the opposite direction and return the dividers to the mold.
Additional elements required for a completely automatic operation of the ice maker through successive freezing and ice harvesting cycles include means for introducing a charge of water into the mold, means for energizing the motor in order to initiate an ice harvesting cycle and means for stopping the ice making operation whenever the receptacle 3 is full or out of position.
The water supply means includes a filler tube 65 connected through a solenoid valve 66 to a suitable source of water supply. When the solenoid valve 66 is energized to open the valve, water supplied to the mold from the outlet end of the supply tube 65 discharges into a filler spout 67 having its lower or discharge end 68 disposed adjacent the end wall 6 of the mold. The
water thus introduced into the mold flows from compartment to compartment through the slots or grooves 23 and around the ends 26 of the movable dividers.
In order to initiate an ice harvesting cycle after the water charge in the mold has frozen into ice, there is employed a control circuit including a bellows-operated switch 70 shown in the wiring diagram of FIG. 7. This switch is mounted within the housing 35. The sensing bulb component of switch 70 is in the form of a capillary tube 71 extending through the wall 40 and downwardly along that wall into a control compartment 72 provided at one end of the ice mold. As is shown more particularly in FIGS. 2 and 4 of the drawing, this control compartment is defined by walls including the housing Wall 40 and the mold end walls 6 and is of a relatively small volume as compared with the ice making compartments 11. In addition, the bottom wall 74 of the control compartment 72 is elevated above the bottom wall 14 of the mold and one or more holes 75 are provided in the end wall 6 for the flow of water between the control compartment 72 and the adjacent ice making compartment 11. A small slab or piece of ice is formed in a control compartment 72 during each ice making operation and the control is regulated to respond to the decreasing temperature of the ice formed in the control compartment to initiate the start of the ejection cycle by energizing the motor 36. In order to prevent the accumulation of stagnate water in the control compartment 72, the outlet end 68 of the filler spout partially overlaps this control compartment so that each time water is introduced into the mold a portion of that water will flow through and flush the control compartment while each time heat is applied to the mold the small ice piece formed in the control compartment will melt and the resultant water fiow from the control compartment through the holes 75 into the mold proper.
To assure complete freezing of all of the water in the mold before energizing of the motor 36, the sensing bulb 71 is preferably continuously warmed slightly by means of the heater 78 which is shown in the control circuit of FIG. 7 and which is arranged in heating contact with the sensing bulb 71 as well as the bellows component of the switch 70. The purpose of this heater is two fold. It biases the sensing bulb to a temperature a few degrees above the actual mold temperature to assure that the water adjacent the movable dividers 12 which is the last to freeze will be frozen before energization of the motor. In addition, it maintains the bellows component at temperatures above the freezing temperatures existing in the freezer compartment 2.
In order to stop the ice maker and prevent discharge of ice from the mold whenever the receptacle 3 is removed from its receiving position beneath the mold, there is provided a switch 80 for opening the ice maker control circuit and completely de-energizing all of the components thereof whenever the receptacle is out of place. In the embodiment of the invention shown in the drawing, the ice maker receptacle is supported on a shelf 81 forming part of the drawer structure 82 slidably supported within the compartment 2 so that the switch 80 is arranged along the front of the cabinet adjacent the access opening to the compartment 2. When the drawer is in its closed position the switch 80 is closed but when the drawer is moved to an open position thereby carrying with it the receptacle 3, the switch 80 is opened.
After a number of ice making cycles, receptacle 3 becomes filled with ice pieces. To stop the ice making operation when this occurs, the control circuitry includes a normally closed switch 88 actuated by an extension of U-shaped feeler arm 84 which is pivotally mounted at each end along the side 9 of the ice mold. Normally, this arm 84 hangs downwardly into the receptacle 3 but during each ice making cycle it is raised out of the receptacle so that when it returns to its normal position within the receptacle, it will rest on top of the added amount of ice if that amount has substantially filled the receptacle 3. For this raising action, the feeler arm includes, within the housing 35, an extension or actuating arm 85 which rides on a cam surface provided on the rear side of the cam assembly 42 as viewed in FIGS. 3 and 6. This cam surface is arranged so that when the shaft 18 is in the position in which the movable dividers are within the mold, the feeler arm 84 depends into the receptacle 3. Upon rotation of the shaft, con tact of the cam surface with the actuating arm 85 causes this arm to move outwardly from the vicinity of the shaft 18 thereby raising the feeler arm 84 out of the receptacle to the position shown in FIG. 6. At the same time the normally closed switch 88 positioned below the arm 85 is opened. When the pawl 47 disengages the drive arm 44, the spring 50 causes the dividers 12 to return to the mold and also reverses the direction of rotation of the cam element so that the feeler arm 84 will again return to its normal position in the receptacle and the actuating arm 85 will engage and close the switch 88. If for any reason the dividers 12 are prevented from returning to their normal position in the mold in which they are frozen into engagement with the ice pieces, the cam element 32 will also prevent movement of the arm 85 to a position inwhich the switch 88 is closed thereby preventing continued operation of the ice maker under conditions in which the movable dividers would not be positioned to freeze into engagement with and thereafter remove ice pieces from the mold.
Occasionally, full return of the dividers to the mold may be prevented by an ice piece which has. accidentally separated from its divider 12 during movement thereof out of the mold and has fallen back into the mold in the path of one of the dividers 12. To prevent such an ice piece from rendering the ice maker inoperative means are provided in accordance with the present invention for assuring energization of the mold heater 27 whenever, and as long as, the divider elements 12 are prevented from returning to their normal position within the mold following the harvesting cycle. As a result,
any ice piece, such as thatindicated by the numeral 31 in FIG. as interfering with the return of the dividers, is melted by the energized heater. The control means for energizing heater 27 under this condition comprises a single pole double throw snap action switch 52 secured to housing wall 40 and having an operating arm 53 adapted to be engaged by the cam 42 during the time that the dividers are out of the mold. The manner in which switch 52 is connected into the control circuitry to accomplish this purpose will be more fully described in connection with the description of that circuitry and the automatic operation" ofthe ice maker.
7 During, freezing'of a 'charge'of water in the mold 5, the temperaturesensed by the sensing bulb 71 gradually decreases to the point where a slab of ice is formed in the control compartment 72. Since the control heater 78 is designed to maintain the control bulb 71 at a temperature which lags the actual temperature within the control compartment 72 by a few degrees, the switch 70 will not operate until the biased control bulb senses a temperature of for example 15 degrees P. which is sufficiently low to assure complete freezing of all of the water in the mold. At this point, the switch arm 97 forming part of the switch 70 controlled by the thermostat including the sensing bulb 71 moves into contact with the contact 98. With the drawer switch 80 and an overheat switch 91 closed and the feeler arm in its normal position so that switch 88 is closed, a circuit is completed between the supply conductors 100 and 101 to energize the motor 36 through the normally closed switch 102 constituting one of the switches operated by cam 103. At the same time, heater 27 is also energized through a circuit including switch 52 and switch arm 54 of which is in contact with pole 55 when the dividers 12 are in their normal position within the mold. A few degrees of motor rotation is permitted before the arm 44 carried on the 'drive shaft 45 engages the pawl 47 connected to the shaft 18. During this initial rotation, switch cam 103 driven by the shaft 45 closes a holding switch 104 to establish a motor holding circuit which includes cam op erated switch 102. Both of these circuits bypass the feeler arm switch 88 and contact 98 of the control switch 70. The switch 104 remains closed regardless of the operation of the feeler arm or the control switch until the end of cycle or in other words through one complete revolution of the shaft 45.
Since the movable dividers 12 are frozen solidly into engagement with the ice in the mold, the drive motor stalls until sufficient heat is applied by the heater 27 to the mold to melt the bond between the ice pieces and the mold end, side and bottom walls and the surfaces of the fixed dividers 10. At this point, the motor again rotates, lifting the movable dividers 12 upwardly and outwardly over the side 8 of the mold to a point where the ice pieces engage the bumpers 30. Continued rotation of the shaft 18 causes the ice pieces to break free from the dividers and drop into the storage container 3.
After the movable dividers have moved to a point between the bumpers 30 which assures complete release of the ice pieces carried thereby regardless of size or thickness, the pawl 47 carried by the pawl and cam assembly strikes the projection 48 and disengages from the motor drive arm 44. This allows the motor to continue rotation in the same direction while the return spring 50, biasing the dividers to their normal position within the mold, is provided for returning the dividers to that position thus conditioning the dividers for the subsequent manufacture of another batch of ice pieces.
Rotation of cam 42 upon melting of the ice pieces free of the mold permits switch arm 54 to move into engagement with pole or contact 56 so that heater 27 is connected across lines 100 and 101 through the overheat switch 91 and remains energized as long as the dividers 12 are out of the mold. The normally closed overheat switch 91 in the circuit including contact switch 70 is designed to open when an excessive mold temperature is sensed by bulb (not shown) in contact with the mold and thereby de-energize the motor, solenoid valve and heater under overheat conditions.
During the harvesting operation, the ice in the control compartment increases in temperature and begins to melt causing the temperature of the sensing bulb 7 1 to rise due to the heat from the mold added to that from the control heater 78. Water formed by melting ice flows out through the holes 75 into the mold. At a temperature of, for example, 25 F., and even though some ice remains in the controlcompartment, the switch arm 97 forming part of the control switch 70 moves into contact with a warm contact 106. When this occurs, a second holding circuit for energizing only the motor is completed through the closed holding switch 104, and the warm contact-106 of switch 70. Unless this motor circuit through the contact 106 is established before the switch cam 103 opens switch 102 to break the first circuit to the motor, the motor is deenergized until the switch arm 97 does make contact with contact (106.
After the holding circuit through contact 106 is established, further rotation of the switch cam 103 closes the switch contacts 107 to energize the solenoid valve 66 to introduce a measured charge of water into the mold through the filler spout 67. Thereafter, during the final few degrees of rotation of the switch cam 103, the switches 102, 104 and 107 are returned to their normal or starting positions and reset for a subsequent ice making cycle. The opening of switch 104 de-energizes the mold heater 27 and breaks the circuit including switch contact 106 to de-energize the motor 36.
Unless the receptacle 3 is filled with ice, the feeler arm 84 will also return to its normal position within the receptacle thereby closing the feeler arm switch 88 so that when switch arm 97 subsequently moves into engagement with contact 98 another harvesting cycle is initiated. If on the other hand the ice receptacle is full of ice, the feeler arm will be held in a raised position by the ice pieces so that the switch 88 is maintained in an open position and the motor 36 and heater 27 cannot be energized.
To prevent the ice maker from becoming inoperative in the event a stray ice piece in the mold blocks the return of the dividers 12, switch 52, operated through arm 53 by the cam 42, will energize heater 27 as long as the movable dividers are out of the mold. As previously described switch 52 includes a first pole or contact 55 for connecting the heater to control switch 76 when the cam 42 is in initial position shown in FIG. 3 that is the position in which the dividers -12 are in their normal position in the mold and shoulder 58 of cam 42 contacts the operating arm 53 for switch 52 to hold the switch arm in contact with contact 55 against the biasing action of spring 57. This first heater circuit provides for initial energization of heater 27 and warming of the mold at the beginning of the harvesting cycle when control switch arm 97 engages cold contact 98. At the same time, motor 36 is energized through switch 102. As the motor operated cam 42 rotates in a clockwise direction as viewed in FIG. 3, shoulder 58 of cam 42 disengages operating arm 53 so that biasing spring 57 throws switch arm 54 into engagement with pole 56. The mold heater 57 is thereby connected directly across lines 190 and 101 and remains energized until cam 42 is again returned to its first position corresponding to that in which the movable dividers are returned completely to their normal position within the mold. Upon seating of the dividers, switch arm 54 disengages contact 56 and returns to its initial position in engagement with contact 55 in which the energization of heater 27 is controlled by the circuit including contact 55 and switch 70.
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. An automatic ice maker comprising an ice mold in which water is frozen into ice, means for heating said mold to break the bond between said mold and the ice formed therein, transfer means for harvesting said ice from said mold comprising an element normally extending into said mold and frozen into engagement with said ice and movable during each ice harvesting cycle upwardly out of said mold to a harvesting position outside of said mold and then back into said mold, means for removing the ice from said element in said harvesting position, and control means for operating said heating and transfer means comprising a control switch operative in response to the temperature of said mold and a heater switch operated by said transfer means, each of said switches being movable to either of two positions, said switches being series connected in their first positions when said transfer means extends into said mold to complete a first circuit to energize said heating means in response to theformation of ice in said mold, said control switch being movable to its second position in response to an increased temperature of said mold during operation of said transfer means, said heater switch being moved to its second position when said transfer means moves out of said mold to complete a second circuit for energizing said heater independently of said control switch during the time said transfer is out of said mold.
2. An automatic ice maker comprising a refrigerated ice mold, heating means for thawing ice free of the mold, transfer means frozen into engagement with the ice for removing the ice from the mold and movable out of said mold to a harvesting position, control means for operating said heating and transfer means, said control means comprising a control switch and a heater switch, each movable to either'of two positions, said switches being series connected in their first positions to complete a first circuit to energize said heating means in response to the formation of ice in said mold, said control switch being movable to a second position breaking said first circuit and operating said transfer means for movement thereof to its harvesting position, means for returning said transfer means back into said mold, said heater switch being movable to a second position by said transfer means for energizing said heater independently of the position of said control switch when said transfer means is out of said mold.
References Cited in the file of this patent UNITED STATES PATENTS 2,717,496 Andersson Sept. 13, 1955 2,717,498 Shagalolf Sept. 13, 1955 2,718,125 Horvay Sept. 20, 1955 2,757,520 Sampson Aug. 7, 1956 2,844,008 Barton July 22, 1958