US2717504A

US2717504A - Ice maker

Info

Publication number: US2717504A
Application number: US456108A
Authority: US
Inventors: Carl J Knerr
Original assignee: Servel Inc
Current assignee: Servel Inc
Priority date: 1954-09-15
Filing date: 1954-09-15
Publication date: 1955-09-13
Anticipated expiration: 1972-09-13

Description

C. J. KNERR Sept. 13, 1955 ICE MAKER 2 Sheets-Sheet 2 Filed Sept. 15, 1954 United States Patent ICE MAKER Carl J. Knerr, Evansville, Ind., assignor to Serve], Inc., New York, N. Y., a'corporation of Delaware Application September 15, 1954, Serial No. 456,108

Claims. (Cl. 62-7) This invention relates to automatic making, harvesting, drying and storing of ice pieces, generally called ice cubes.

This invention relates particularly to an automatic ice maker that is adapted for installation into a conventional household refrigerator without appreciable modification to the refrigerator cabinet or to the refrigerating unit that cools the several compartments of such cabinet.

The modern household refrigerator is provided with a low temperature or freezing compartment and with a food storage compartment of higher temperature. The freezing compartment is generally constructed with a boX- like liner that is cooled by one or more refrigerating coils attached to the exterior of the top, bottom and/or side walls thereof. In some instances the liner for the freezing compartment is of double walled construction with cooling refrigerant between such walls.

it is an object of this invention to provide a self-contained automatic ice maker having a freezing mold that is adapted for attachment to and cooled by a side wall of the freezing compartment of an otherwise conventional refrigerator.

It is a further object of this invention to provide means for thawing ice free of an ice mold without appreciably heating a refrigerated wall to which the mold is attached for cooling.

It is a further object of this invention to provide an automatic ice maker in an otherwise conventional refrigerator wherein there is no need for discontinuing the operation of the refrigerating system during the thawing of ice from the mold in which it is frozen.

The invention, together with the above and other objects and advantages, is set forth in more technical detail in the following description and accompanying drawings, wherein:

Fig. 1 is a horizontal section, taken on line 11 of Fig. 3, and showing the ice maker in top plan with parts in horizontal section;

Fig. 2 is a detail of parts of a microswitch and cam mechanism for controlling the operation of a solenoid water valve;

Fig. 3 is a transverse vertical section through the freezing compartment of a household refrigerator with the automatic ice maker attached to a side wall thereof, and taken on line 33 of Fig. 1; and

Fig. 4 is a schematic wiring diagram of the controls for the ice maker.

For purpose of illustration, I have incorporated my invention in an automatic ice maker generally similar to that disclosed in my companion patent application, Serial No. 456,106, filed concurrently herewith. Therefore, for a detailed description of parts omitted from the instant application, reference may be had to said companion application.

General description Referring to Figs. 1 and 3 of the drawings, the ice maker, indicated generally by reference numeral 10, is

2,717,504 Patented Sept. 13, .1955

removably located within the upper or freezing compartment 11 of a household refrigerator 12. The entire ice maker is inserted as a unit through an opening 13 (Fig. 1) in the rear wall of the refrigerator, which opening is closed by a closure member 14 attached by screws 15 to said rear wall. The front of the refrigerator is closed by the usual door (not shown). The ice maker is removably attached to the left side wall 11a (Fig. 3) of the freezing compartment 11 of the refrigerator by a plurality of screws 16, which screws are threaded into nuts 16a that are welded or otherwise secured to the exterior of such side wall. A refrigerating coil 17 is welded or otherwise secured to the exterior of the side wall 11a. The left side wall 11a of the freezing compartment is provided with a row of slots orelongate openings 11b immediately above and below the lines of attachment of the ice maker to the side wall, which slots act as thermal breaks for the refrigerant coil 17.

The freezing compartment 11 of the refrigerator is cooled by a second refrigerating coil 18 attached to the bottom wall 110 thereof. The refrigerating

coils

17 and 18 are connected in the usual manner, either in series or in parallel, to a conventional refrigerating system (not shown). Resting on the bottom wall 11c of the freezing compartment below and to the right of the ice maker, as viewed in Fig. 3, is an ice receptacle 19, adapted to receive and store ice pieces discharged from the ice maker. Only so much of the refrigerator as is necessary for a complete understanding of this invention is shown in the drawings.

Referring now to Fig. 1, the ice maker includes, generally, an ice mold 20, provided with a mold heating element 30 (Fig. 3). The ice mold is surrounded at the right side, front and bottom by thermal insulation, and the insulation is encased in an insulation housing. The rear ice-forming compartment of the ice mold is closed by a combined closure member and support 40, which member is formed of plastic, such as phenol formaldehyde, or other suitable thermal and electrical insulating material. An ejector mechanism 50 is mounted above the ice mold for rotary movement therethrough for sweeping the ice pieces therefrom, and is journalled at its front end in a bearing at the upper front end of the mold, and at its rear is the rear closure member 40.

As disclosed in my above copending application, the rear closure member 40 is generally in the shape of a box, open at the rear and closed by a metal closure plate 41, which closure plate supports three

microswitches

80, 90 and 100, and provides bearing surfaces for a rear ejector shaft and a timing gear shaft, to be referred to in detail hereinafter. Of the three microswitches: the microswitch is operated by a cam on the timing gear shaft and, if desired, it deenergizes the compressor motor 120 (see wiring diagram, Fig. 4) of the refrigerator system at the start of an ice release cycle; the microswitch is operated by the same cam, and this microswitch energizes a solenoid-operated water valve 70 (Fig. l) for a precise number of seconds near the end of the ice release cycle; and the microswitch is operated by a cam mounted on a shut-ofi mechanism, which mechanism is mounted on the rear closure member 49 and acts as a cut-off to deenergize the ice maker when the ice receptacle 19 contains a given amount of ice pieces.

Mounted on the rear of the metal closure plate 41 is a gear housing 63 which contains and journals an ejector gear 57, a timing gear assembly 65 and a motor gear 62, to be referred to in detail hereafter. An electric motor 60 for driving the ejector mechanism and the controls therefor is mounted on the rear of the gear housing 63. This electric motor 60 is geared down from 3400 R. PJM. to approximately 2.5 R. P. M. at the output shaft, and is of a type that stalls while energized when the ejector blades initially contact the ice frozen solidly in the mold without burning out or otherwise harming the motor. A motor of this type is disclosed and claimed in a copending patent application of Sven W. E. Andersson, Serial No. 325,145, filed December 10, 1952. Mounted on the right side of the ejector motor 6% (as viewed in Fig. 1) is the precision solenoid-operated Water valve 70; the inlet of which valve is connected to a suitable source of water under pressure, such as the house line, and the outlet of which valve is connected by a conduit to a passage 42 formed in the rear closure and support member 40, which passage discharges water into the rear iceforrning compartment of the mold. As stated above, the entire ice maker is inserted as a unit through an opening in the rear wall of an otherwise conventional household refrigerator.

Referring now to Figs. 1 and 3, the ice mold comprises an aluminum die casting divided into a plurality of ice-forming compartments 21 by transverse partitions 22. The ice-forming compartments are generally semi-circular in transverse vertical section (Fig. 3), and the partitions are tapered horizontally from the right to the left side thereof as viewed from the front in Fig. 1. For reasons pointed out in detail in my above companion patent application, the partitions 22 have a slight taper in the vertical direction. The partitions are each provided with an upstanding projection 23 on the right side and with a weir or notch 24 in the left side thereof, as viewed in Fig. 3. A thermal insulator 25, made of nylon or the like, is fitted upon each of the upstanding projections 23 of the mold partitions. As shown in Fig. 3, and as pointed out hereinafter, the insulators 25 support one side of the ice pieces during the drying thereof and prevent the ice from sticking to the upstanding projections of the mold partitions. The outer surface of each of the weirs 24 is of the same general curvature as the inner surface of the ice mold compartments, and the inner surface of the weirs is substantially vertical. As viewed in Fig. 1, the weirs are progressively smaller from the rear to the front of the mold.

Referring to Fig. 3, the ice mold 20 is formed with a mass of metal 26 along the left side thereof which terminates in upper and lower longitudinal flanges 27 along the length thereof. The attaching screws 16 are inserted through openings in the flanges 27, and the elongate slots 11b are located in the side wall 11a immediately above and below the flanges 27. With this arrangement the transfer of heat to the refrigerating coil 17 is substantially limited to that transferred from the Water in the ice mold compartments through the mass of metal 26 and the portion of the side wall 11a, to which the mold is attached, to the coil 17.

In the embodiment of the invention disclosed herein, the ice mold is shown attached to a side wall of the freezing compartment liner. which liner is of single thickness and is cooled by a refrigerating coil attached to the exterior thereof. The invention may, however, be applied with equal facility to a double walled liner wherein the space between the two walls forms an evaporator of the refrigerating system. In which case, suitable flanges or the like, not shown, may be provided on the freezing compartment side of such wall for attaching the ice mold thereto without piercing the liner.

The front and rear walls 28 and 29, respectively, of the mold slant outward from right to left as viewed from the front in Fig. 1. A mold heater 30, in the form of an arcuate plate (Fig. 3), is located externally of the mold casting against the bottom and right sides thereof.

As shown in Fig. 3, the ice mold casting is relatively thin in the vicinity of the mold heater 30. With this arrangement, when the mold heater is energized during ice release cycles of operation, heat is transferred to the bottom of the mold and from there to the mold partitions to free the ice of the mold compartments. Thus, the ice is thawed free of the mold without appreciably raising the temperature of the side wall of the freezing compartment and without having to buck the refrigerating effect of the coil 17. For this reason, it is not necessary to discontinue operation of the refrigerating system during an ice release cycle.

The front of the mold casting is provided with an integral boss drilled to receive a bearing 32 (Fig. 1) made of nylon or other suitable heat insulating material. The bearing 32 receives and supports the front end of the ejector shaft 51, to be referred to hereinafter. As shown in Fig. 1, the front ice-forming compartment of the mold is formed with an overflow duct 33 that assures against excess filling of the ice-forming compartments, as pointed out hereinafter. In case of overflow, the duct 33 discharges into the ice receptacle 19, that is located beneath and to the right of the mold, as shown in Fig. 3.

Ice mold insulation So as to confine the heat transferred to the refrigerating coil 17 to that extracted from the water in the ice mold compartments and transferred therefrom through the mold and the side wall 11a to the coil 17, and to add to the decor of the ice maker, the mold is provided with insulation and with decorative housing members at the right side, bottom and front thereof. The insulation members are made of unicellular sponge rubber that is impervious to moisture and, as shown in Fig. 3, include a one-piece bottom and right side member 34 formed to fit the exterior contour of the mold casting and held in place by a housing member 35. The front insulation member, not shown, is formed to lit the front contour of the mold and is held in place by a front housing member 37 (Fig. 1). As shown in Fig. 3, the housing member 35 is arcuate in transverse section and is provided with upper and lower flanges 35a and 35b, which flanges are adapted to fit into upper and lower slots 20a and 29b, respectively, formed along the right upper and left lower edges of the mold casting. The front housing member 37 is shaped as disclosed in my above copending application, Serial No. 456,106, and is provided with a bracket 38 attached to the front of the ice mold casting by a pair of screws 39. The rear of the ice maker, that is, all parts to the rear of the metal closure plate 41 (Fig. l) are embedded in thermal insulation (not shown) that is blown into the spacer or opening 13 after the ice maker has been inserted into the refrigerator.

Ejector mechanism The ejector mechanism 50 includes a front ejector shaft 51 mounted for clockwise rotation (Fig. 3) at front end in the nylon bearing 32 (Fig. l) at the front of the ice mold and at its rear end in a suitable bearing located in the rear closure member 40, which member. as pointed out heretofore, is made of thermal insulating material. Extending tangentially (Fig. 3) from one side of the front ejector shaft 51, and formed integral therewith, is a plurality of ejector blades 52; there being one such blade for each ice-forming compartment 21 of the ice mold 25 The ejector shaft 51 is mounted in the plane of the longitudinal axis of the ice mold, and as shown in Fig. 3, is spaced from the upper edges of the mold partitions 22. At the rear, this ejector shaft 51 is connected by a thermal insulating coupling 54 (Fig. l) to a rear ejector shaft 56, which rear ejector shaft is connected to the ejector motor 63 by a. novel timing gear assembly 65, to be described in detail hereinafter. As shown in Fig. 3, the outer upper edges of the ejector blades 52 cooperate with the insulators 25 in supporting the ice pieces above the ice mold for drying wetted surfaces thereof before discharge into the storage receptacle 19.

Power and timing mechanism The power and timing mechanism is the same as that discl05d in my copending application, Serial No. 456,106,

and, as pointedoutheretofore, the electric motor 60 for driving the ejector mechanism and the. controls therefor is a stall motor equipped with internal gears (not shown) for reducing its speed from 3400 R. P. M. to approximately 2.5 R. P. M. at its output shaft 61. The motor fiel-d winding a and overload limit switch 6% are shown diagrammatically in Fig. 4. The motor. output shaft 61 (Fig. l) is formed with a square portion 6111 upon which is keyed a gear 62. The motor gear 62 is meshed with a rear gear 67 of the timing gear assembly 65, which timing gear assembly is fixedly mounted on a shaft 66, journalled at its rear in a bearing 66a formed in the gear housing 63 and at its front in a bearing (not shown) formed in the metal closure plate 41. In front of the gear 67 (as viewed in Fig. 1) is a timing gear 68 having a toothed portion 68a and a blank portion 68b on the periphery thereof. In front of the timing gear 68 is a timing cam 69 having a high portion and a low portion (not shown) on the periphery thereof. The gears 67 and 68 and the cam 69 are held as an assembly by a pair of dowel pins (not shown). Fixedly mounted on the rear ejector shaft 56, and in mesh with the teeth of timing gear 68, is an ejector gear 57, and

in front of the ejector gear (Fig. l) and fixed to the.

rear ejector shaft 56 is an ejector cam 58 having a high portion and a low portion (not shown) on theperiphery thereof.

The arrangement is such that upon rotation of the ejector motor 60, the motor gear 62 rotates the rear gear 67 of the timing gear assembly, whichtwo gears have meshing teeth throughout the 360 of their periphery, and.

rotation of the gear 67 causes rotation of the timing gear 63 and of the timing cam 69. As the timing gear 68 is rotated, the toothed portion 68a thereof is brought into mesh with the teeth of the ejector gear 57, which latter gear is provided with teeth throughout the 360 of its periphery, whereupon the ejector gear 57, the rear ejector shaft 56, the ejector cam 58 and the front ejector shaft 51 are rotated in unison. Rotation of the ejector gear 57 continues (neglecting for the present the stalling of the ejector mechanism by contact of the ejector blades 52 with the ice frozen solidly in the mold compartments) until the blank portion 68b of the timing gear 63 is juxtaposed with the teeth of the ejector gear at which time the high portion of the timing cam 69 is in mesh with the low portion of the ejector cam 58, whereupon the ejector gear 57 and shafts 56 and 51 are held stationary while the ejector motor 60, the motor gear 62, and the timing gear assembly and cam 69 continue to rotate for a definite period before the motor is deenergized, as pointed out hereinafter. During a freezing cycle of operating, the timing gear 68 and the ejector gear 57 are in such relative positions that the high portion of cam 69 is in contact with the: low portion of cam 53. Thus the ejector mechanism is locked in the position shown in Fig. 3 for drying the ice pieces resting thereon.

Water metering and mold filling mechanism Mounted on a bracket 71 on the side of themotor 60 is the solenoid-operated water valve 70 (Fig. 1) This valve is a precision mechanism in that it accurately meters a definite quantity of water therethrough when open; the opening and closing of which is accurately timed as pointed out hereinafter. This valve includes a body member 71 having an inlet connection 72 and an outlet connection 73. The inlet connection is provided with a nipple 72a that extends through a rear closure plate for connection to a suitable source of water under pressure, such asthe house line. The outlet connection 73 is connected to the-ice mold by a tube 74 that opens into the passage 42 formed in the rear closure member 40.

For a detailed description of the solenoid-operated-valve:

70 reference may be had to my copending application, Serial No. 456,106.

6 Controls- As disclosed in my copending application, Serial No. 456,106, the rear ice-forming compartment of the ice mold casting is open 'andis closed by the rear closure and support member 40, which member is formed of a plastic, suchas phenol-formaldehyde which is a good thermal and electrical insulation. Integrally formed on the front face of the closure member 40 is a raised portionthat fits into the rear of the ice mold and forms the rear wall 29 (Fig. l) of the rear ice-forming compartment. The rear wall 29'is provided with an insulator 25a, similar to the insulators 25 on the upper edges of the mold partitions 22. A gasket (not shown) seals the rear outer surface of the mold casting against the adjacent front surface of the closure member 40. The purpose of the insulating rear wall 29 of the ice mold is to make sure that the water in the rear ice-forming compartment is last to freeze, and complete freezing of the water in this rear compartment is utilized to energize "the ice release mechanism; as disclosed and broadly claimed in the copending patent application of Harry C. Shagalofl, Serial No. 325,097, filed December 10, 1952.

A mold thermostat 76, operatively responsive to the complete freezing of the water in the rear ice-forming compartment of the mold for energizing the ejector motor 60, a metal insert 77 for transferring heat from the water in the rear compartment of the mold to the thermostat sensing element (not shown), and a reset heater 78 for resetting the mold thermostat, the same as that disclosed in my copending application, Serial No. 456,106, are incorporated in my instant ice maker. However, only the mold thermostat 76 (shown diagrammatically in Figs. 1 and 4), themetal insert 77 (Fig. 3) and the reset heater 78 (Fig. 4) are shown in the drawings. For a detailed description of these elements reference may be had to my above copending application.

Referring now to Figs. 1 and 4, the micro switch 80, which deenergizes and energizes the compressor motor 120 (shown only in the wiring diagram in Fig. 4) at the beginning and end, respectively, of an ice release cycle, and which provides a holding circuit for the ejector motor 60, is mounted by a pair of screws 82 upon a bracket 83, which bracket in turn is welded or otherwise secured to the closure plate 41. This micro switch includes a springpressed plunger 81 that is urged into contact with a cam 86, to be described in detail hereinafter, and when in contact with the high portion of the cam, which is the stationary position of the cam during an ice freezing cycle, the switch is in the full line position shown in Fig. 4 and the compressor motor 120 is energized; whereas shortly after the beginning of an ice release cycle, the high portion of the cam 86 leaves the plunger 81, and the switch is shifted to the broken line position (Fig. 4), whereupon the compressor motor is deenergized, and remains so until near the end of an ice ejecting cycle whenthe high portion of the cam again contacts the switch plunger 81 and returns the switch 80 to the full line position. It may be desirable, with certain installations, to continue operation of the refrigerating system during ice release cycles. In which case, the conductor 122 for the compressor motor 120 is connected directly to the conductor T2, and the micro switch S0 is used only to provide a holding circuit to the ejector motor 60 during ice release cycles of operation. These changes to the wiring diagram (Fig. 4) are obvious and need not be shown in the drawings.

The second microswitch 90(Fig. 2), which energizes and deenergizes the solenoid valve 70, is also mounted on the closure plate 41 by a bracket and a pair of screws 92. This switch 90 is located below the switch 80 (Fig. 1) and'includes a plunger 91 operated by a lever 93 (Fig. 2). The lever 93 is pivoted near its lower end on a post 94, and at its upper or free end is bifurcated to receive a roller 95. The roller rides upon the cam 86 and is urged into contact therewith by a compression spring 97. The cam 86 (as shown in Figs. 1 and 2) comprises a front portion 860: fixedly mounted on the timing gear shaft 66 and a rear portion 86b adjustably mounted by a set screw 87 upon the shaft 66. The purpose of this adjustment is to vary the combined length of the high or camming surfaces of the front and rear portions of the cam; the combined length of which high portions of the cam determine the length of time that the solenoid valve 70 is energized and water flows therethrough to the ice mold. It is to be noted that the plungers 81 and 91 of

micro switches

80 and 90, respectively, are operated by the same cam 86 and during an ice freezing cycle the

switches

80 and 90 are in the full line positions (Fig. 4) with the compressor energized and the solenoid valve deenergized.

The micro switch 100, that automatically deenergizes the ice maker when the ice receptacle 19 (Fig. 3) is filled with a given amount of ice pieces, is mounted on a bracket 102 (Fig. l), the lower end of which is attached by a screw (not shown) to the metal closure plate 41, and the upper end of which is adjustably connected to the closure plate by a screw 104 having a compression spring 105 thereon. The microswitch 100 includes a springpressed plunger 101 operated by a cam 106 mounted on a shaft 107, which shaft is journalled at its ends in partition walls 43 and 44 of the rear closure member 40. The purpose of the adjusting screw 104 is to center the plunger 101 below the cam 106. A lift arm 110, including a sleeve 111 with a roller 112 attached thereto by a shoulder screw (not shown), is fixedly and adjustably mounted on the shaft 107, near the partition wall 43. A second sleeve 114 is attached to the opposite end of the shaft 107 and an arm 115, made of stainless steel or other relatively rigid material, is attached at one end to sleeve 114. The arm is formed with an offset near its attached end and is provided with a relatively heavy metal ball 116 on its free end. The lift arm 110 is raised by a cam member 86c (Fig. 2) formed on the front surface of the cam 86.

The arrangement is such that upon rotation of the timing gear assembly 65 the high portion of the cam 86c is brought into contact with the roller 112 (Fig. 1), whereupon the shaft 107 is rotated in a clockwise direction for a given amount. This clockwise rotation of the shaft 107 brings the high portion of cam 106 into contact with the switch plunger 101, which depresses the plunger and opens the switch 100 (Fig. 4), thereby opening the circuit to the ejector motor 60 in which this switch is contained. Clockwise rotation of the shaft 107 also lifts the stop arm 115 and attached ball 116 to a first or intermediate position (not shown). Continued rotation of the timing gear assembly 65 (Fig. 1) causes the high portion of cam 860 to leave the roller 112 on the lift arm 110, whereupon, assuming that the ice receptacle 19 (Fig. 3) is not yet filled with ice pieces, the ball 116 falls by gravity and through the arm 115 rotates the shaft 107 counterclockwise to its normal position which removes the high portion of cam 106 from the switch plunger 101, and this in turn causes the switch 100 to return to its closed position (Fig. 4). Should the ice receptacle 19 be filled with the desired amount of ice pieces, gravity movement of the ball 116 and stop arm 115 is blocked by the ice, causing the switch 100 to remain open after the high portion of cam 86c has left the lift-arm 110 and until some ice has been removed from the receptacle 19.

Mounted on the top wall of the freezing compartment of the refrigerator (Fig. 3) directly above the stop-arm 115 is a spring clip 117. With this arrangement, the ice maker may be shut down and caused to stand idle at will by manually lifting the ball 116 and stop-arm 115 and engaging the arm in the spring clip 117. With the stop-arm 115 engaged in the spring clip 117, the ice maker will complete a freezing cycle, but, because the switch blade 100a (Fig. 4) is held open, a subsequent ice ejecting cycle cannot be initiated. Therefore, the ice 8 maker stands idle with a batch of ice pieces frozen in the mold and a second batch of ice resting on the ejector mechanism above the mold (Fig. 3) ready to be discharged into the storage receptacle 19. Operation of theice maker may be resumed by manually removing the stop-arm 115 from engagement with the spring clip 117.

Wiring diagram Referring now to Fig. 4, T1 and T2 are the two sides of a 115 volt A. C. supply circuit, between which are connected, by several circuits, the compressor motor 120 for the refrigeration system, the micro switches 80, 9t) and 100, the electric thermostat 76 for the ice mold, the ejector motor 60 with the motor field 60a and limit switch 60b, the mold heater 30, the reset heater 78 with limit switch 780, and the solenoid water valve 70. The full line position of the several switches in Fig. 4 is their normal position during an ice freezing cycle of the ice maker.

A first circuit (the only circuit for the compressor motor 120) includes the conductor T2, a movable switch blade a (in full line position) of microswitch 80, a stationary contact 80b, a conductor 122 in which is located a switch 121a of a thermostat 121 for the refrigerating system, the compressor motor 120, and T1. The sensing element 121!) of thermostat 120 is placed in thermal contact with the refrigerating coil 13 (Fig. 3). As stated heretofore it may be desirable to continue operation of the refrigerating system during ice release cycles of operation, in which case the conductor 122 is connected directly to the conductor T2, the contact 80b becomes a dead terminal and the switch 80 is used only to provide a holding circuit, as described herein after.

A second circuit (a first circuit for the ejector motor 60) includes the conductor T2, a conductor 123, movable switch blade 100a (in full line position) of microswitch 100, a stationary contact 100b, a conductor 124, a stationary contact 76!), a movable switch blade 76a (in broken line position) of the ice mold thermostat 76, a conductor 125, a stationary contact 800, a conductor 126, a stationary contact b, a movable switch blade 90a (in full line position) of microswitch 90, a conductor 127, the motor field 60a, the motor limit switch 60b, a conductor 128, a conductor 129 and T1.

A third circuit (second circuit for the ejector motor 60) includes the conductor T2, movable switch blade 80a (in broken line position) of microswitch 80, the stationary contact 80c, conductor 126, stationary contact 90b, movable switch blade 90:: (in full line position), conductor 127, motor field 60a, motor limit switch 60b, conductor 128, conductor 129 and T1.

A fourth circuit (third circuit for the ejector motor 60) includes the conductor T2, movable switch blade 80a (in broken line position), a conductor 125, movable switch blade 76a (in full line position), a stationary contact 760, a conductor 130, conductor 127, motor field 60a, motor limit switch 60b, conductor 128, conductor 129 and T1.

A fifth circuit (a circuit for the mold heater 30 and the reset heater 78, is in parallel with each of the above circuits for the ejector motor 60 between the microswitch 90 and T1) includes a conductor 131, the mold heater 30, a conductor 132, resistance wire 78a, limit switch 780 and resistance wire 78b of the reset heater 78, a conductor 133, conductor 129 and T1. This circuit to the mold heater and reset heater is energized when switch blade a is in full line position, switch blade 76a is in broken line position and switch blade 90a is in full line position, and when switch blade 80a is in broken line position and switch blade 90a is in full line position, and when switch blade 80a is in broken line position and switch blade 76a is in full line position. Thus, the mold heater 30 and reset heater 78 are energized at all times that the ejector motor 60 is energized.-

A sixth circuit (the circuit for the solenoid water valve 70 is in parallel with that part of the circuits for the ejector motor 60 between the microswitch 90 and the motor limit switch 60b) includes the movable switch blade 98a (in broken line position), a stationary contact 990, a conductor 134, the solenoid 70, a conductor 135, the limit switch 68b of the ejector motor,

conductors

128, 129 and T1. This circuit for the solenoid water valve is energized only when the movable switch blade 80a is in broken line position, the movable switch blade 76a is in full line position, the movable switch blade 98a is in the broken line position and the motor limit switch 602; is closed. The movable switch blade 911a is in the broken line position only near the end of an ice release cycle when the high portions of cams 86a and 86b (Fig. 2) are brought into contact with the roller 95 of microswitch 90.

Operation In operation, assuming that the several switches are in the full line position shown in Fig. 4, that the ice receptacle 19 (Fig. 3) is not yet filled with the desired quantity of ice pieces and that the stop arm 115 is in the position in Fig. 3; in other words, the ice maker is in operation. With the several switches in the full line position shown in Fig. 4, the compressor motor 120 is energized and water is being frozen in the several compartments of the ice mold. Due to the fact that the end wall 29 of the rear ice forming compartment of the mold is made of thermal insulating material, water in the rear ice forming compartment will be last to freeze, and when this water is completely frozen, the temperature (26-28 F.) on the surface 77 (Fig. 3) in contact with the water being frozen is reflected through the metal insert to the sensing element (not shown) of the mold thermostat 76, whereupon the thermostat switch 76a is shifted from the full to the broken line position (Fig. 4).

This shifting of the thermostat switch 76a establishes an initial circuit from T2 through connector 123, stop arm switch 101m (in full line position) stationary terminal 100b, conductor. 124, stationary terminal 76b, thermostatic switch blade 76a (in broken line position), conductor 125, stationary conductor 88c, conductor 126, stationary conductor 9%, switch blade 90a (in full line position), conductor 127, motor field 68a, motor limit switch 6%, conductor 128, conductor 129 and T1, whereupon the ejector motor 60 is energized. The shifting of the thermostat switch 76a to the broken line position also establishes a parallel circuit through the conductor 131, the mold heater 30, conductor 132, resistance wire 78a, limit switch 78c, and resistance wire 78b of the reset heater 73, conductor 133, conductor 129 and T1, whereupon the mold heater 3% and the reset heater 78 are energized.

Energization of the ejector motor 60 causes rotation of the motor, motor gear 62 (Fig. 1), timing gear 67, gear shaft 66, timing gear 68, timing cam 69, and cam 86. The ejector motor 6 8 is otherwise unloaded during its initial rotation, and shortly after the cam 86 begins to rotate, the high portion of cams 86a and 86b leave plunger 81 of microswitch 80, whereupon the movable switch blade 80a is shifted from the full to the broken line position in Fig. 4. This shifting of the switch blade 88a deenergizes the compressor 120 of the refrigerating system and establishes a holding circuit from T2 to T1 through the switch blade 80a (in broken line position), stationary contact 8110, conductor 126, stationary contact 90b, movable switch blade 90a (in full line position), conductor 127, ejector motor 60, and

conductors

128 and 129. This shifting of the switch blade 88a also establishes a holding circuit through the mold heater 3%) and reset heater 78. In cases where it is desirable to continue operation of the refrigerating system during ice release cycles of the ice maker, the conductor 122 for the compressor motor 120 is connected directly to the.

conductor T2, as pointed out above, in which case, the shifting of switch blade 80a at the beginning and end of an ice release cycle merely establishes and'discontinues, respectively, the holding circuits.

With continued rotation of the ejector motor and the timing gear assembly, the cam surface 86c on the front of cam 86 is brought in contact with the roller 112 (Fig. l) of the stop-arm assembly 110, whereupon the shaft 107 is rotated clockwise (Fig. 1) with the result that the plunger 101 of microswitch 100 is depressed and the switch blade 100a is shifted from the full to the broken line position (Fig. 4). lifts the stop arm 115 and attached ball 116 to an upper position (not shown). At about this point in the rotation of the ejector motor and the timing gear assembly, the high portion of cam 69 (Fig. 1) will have been .re-

moved from the low portion of cam 58, and the toothed.

portion 68a of gear 68 will have meshed with the teeth of the ejector gear 57, whereupon the ejector gear 57, rear ejector shaft 56, ejector cam 58, coupling member 54 and. the front ejector shaft 51 with fingers 52 attached thereto.

are rotated in a clockwise direction (Fig. 3). This clockwise rotation of the ejector shaft 51 and attached fingers 52 causes the dried ice pieces that have been resting on the ejector fingers 52 and on the insulators (Fig. 3) to be discharged over the side of the mold into the ice receptacle 19.

Shortly after the batch of ice pieces have been discharged over the side of the mold, the timing mechanism will have rotated to the point that the high portion of cam surface 860 will have passed the roller 112 on stop arm assembly 110, whereupon the weighted ball 116 on stop arm 115 will fall 'by gravity (assuming that the ice receptacle 19 is not yet filled with ice pieces) and rotate the shaft 107 counterclockwise (Fig. 1) thereby removing the high portion of cam 106 from switch plunger 101 and returning switch blade 100a to the full line position (Fig. 4). Should the ice receptacle 19' be filled with the de sired quantity of ice, at this point, the weighted ball 116' will be held up by the ice and the stop switch 100a will be held in the broken line or open position (Fig. 4). However, because of the holding circuit through switch blade 80a (in broken line position) the ejecting cycle will continue to completion, but a new ejecting cycle cannot be initiated until some ice pieces are removed from the storage receptacle 19 and the stop switch 100a closed.

The ejector motor 60 continues to rotate until the ejector fingers 52 contact the ice frozen solidly in the several compartments of the mold, whereuponthe ejector motor is stalled. However, the ejector motor 60, the. mold heater and the reset heater 78 remain energized,-

with the motor urging the ejector fingers against the ice so that the instant the ice is thawed free of the mold compartments, the motor resumes its rotation and the ejector blades sweep the ice pieces from the mold and bring them for rest in the drying or upside-down position shown in Fig. 3. By this time the reset heater 78 will have reset the thermostat switch blade 76a to the full line position shown in Fig. 4, and the high portion of cam 106 on shaft 107 will have drawn away from the switch plunger 101 and the switch blade a will have returned to its full line position (Fig. 4), assuming that the ice receptacle 19 is not yet filled with ice and that the stop arm and attached ball 116 have returned to the position of Fig. 3.

By the time that the ejector motor 60 has rotated the ejector shaft 51 and attached ejector blades 52 to the position shown in Fig. 3, the toothed portion 68a of timing gear 68 (Fig. 1) will have left the teethof ejector gear 57, and the high portion of timing cam 69 will be in contact with the low portion of the ejector cam 58, whereby the ejector shaft 51 and attached fingers 52 are locked in the position shown in Fig. 3, and the motor is again unloaded although it continues to rotate. During this un- Rotation of the shaft 107 also.

loaded period of rotation of the ejector motor, the high portion of cams 86a and 86b (Fig. 2) will contact the roller 95 on switch arm 93, whereupon the plunger 91 of microswitch 90 is depressed and remains so depressed for approximately ten seconds during which time the switch blade 96a (Fig. 4) is shifted to the broken line position and the coil of the solenoid water valve 70 is energized, whereupon water in a metered quantity flows through the solenoid valve 70 (Fig. 1), the outlet tube 74, vertical passage 42 and outlet passage 42a (Fig. 3) into the rear ice forming compartment of the mold. From the rear ice forming compartment, the water flows through the notches 24 in the mold partitions to the forward compartments of the mold.

The ejector motor 60 and the timing gear assembly continue to rotate unloaded, whereupon the high portions of cams 86a and 86b withdraw from the roller 95 (Fig. 2) of switch arm 93, thereby shifting the switch 90a back to the full line position (Fig. 4) which deenergizes and closes the solenoid valve 70. Shortly thereafter, the high portions of cams 86a and 86b will have returned to the positions shown in Fig. 1 with the plunger 81 of microswitch 80 depressed and the switch blade 80a shifted back to the full line position in Fig. 4 which ends the ejecting cycle and starts the next freezing cycle, with the ejector motor, the mold heater, the reset heater and the solenoid water valve deenergized, and with the compressor motor energized.

It is to be noted that with the switch blade 90a in the broken line position (Fig. 4), the only circuit to the.

coil of the solenoid water valve 70 is from T2 through switch blade 80a (in broken line position), stationary contact 80c, conductor 125, switch blade 76a (in full line position) stationary contact 760, conductor 1330, switch blade 90a (in broken line position), stationary contact 90c, conductor 134, coil 70, conductor 135, limit switch 60b of the ejector motor, conductor 128, and conductor 129 to T1. Also, with the switch blade 90a in broken line position, the only circuit to theejector motor 60, the mold heater and the reset heater 78 is through conductor 130. Therefore, should the thermostat switch 76a fail to reset to the full line or warm position shown in Fig. 4 by the time the microswitch 90a has been shifted to the broken line position, the entire ice maker is rendered inoperative, with the ejector motor, the compressor motor (unless conductor 122 is connected directly to T2), the mold heater, the reset heater and solenoid water valve deenergized, and with the water valve closed. Inability of the reset heater 78 to reset the thermostat switch 76a is an indication that the thermostat has failed, lost its charge, and must be replaced before the ice maker can be rendered operative.

Also, it is to be noted that the coil of the solenoid water valve 70 is wired in series with the overload limit switch 6% of the ejector motor, so that, should the switch 601) .open for any reason and stop the ejector motor While the high portion of cams 86a and 86b are in contact with the roller 95 (Fig. 2) of microswitch 90, thereby holding the switch blade 90a in the broken line position (Fig. 4) with the solenoid coil 70 energized and the water valve open, the coil is immediately deenergized and the valve closed. Furthermore, the reset heater 78 with bimetal limit switch 780 is wired in series With the mold heater 30, so that excess temperatures of both the mold heater and the reset heater are avoided.

Without further description it is thought that the novel features and advantages of the invention will be readily apparent tothose skilled in the art to which this invention appertains, and it will, of course, be understood that changes in form, proportions and minor details of construction may be resorted to without departing from the spirit of the invention and scope of the claims.

I claim:

1. A refrigerator having a freezing compartment bound by a refrigerated liner, an ice storage receptacle within said freezing compartment, and a self-contained automatic ice maker mounted on a side wall of said liner, said ice maker including an ice mold removably attached in intimate thermal contact to said side wall to be refrigerated thereby, means for filling the mold with water to be frozen, ejector mechanism mounted on the ice maker and including a member movable into contact with ice in the mold for removing ice from the mold and discharging such ice into the storage receptacle, and control mechanism for said mold filling means and said ice ejecting mechanism, said mold, said filling means, said ejector mecharism and said control mechanism being united into a single unit so constructed and arranged as to be readily insertable and removable as a unit into and out of the refrigerator independently of the refrigerated liner.

2. A refrigerator as set forth in claim 1 wherein said control mechanism includes means operable responsive to the freezing of ice in said mold for first energizing said ice ejector mechanism and then said mold filling means in timed relation.

3. A refrigerator as set forth in claim 1 wherein said ice mold is constructed of metal with a mass of metal at one side thereof and having a plane vertical surface coextensive with the length and height of the mold at said one side for attachment in metal to metal contact with the side wall of said refrigerated liner.

4. A refrigerator as set forth in claim 1 wherein said refrigerated liner includes a refrigerating coil attached in thermal contact with the exterior of said side Wall and wherein said ice mold is constructed of metal with a mass of metal at one side thereof for attachment in metal to metal contact With the interior of the side wall immediately opposite said refrigerating coil.

5. A refrigerator as set forth in claim 1 wherein the portion of the side wall of the refrigerated liner to which the ice mold is attached is at least partially thermally insulated from the remainder of said side wall.

6. An ice mold formed of metal and divided by a plurality of partitions into a plurality of substantially semicylindrical ice-forming compartments, said mold being constructed with a mass of metal of substantial thickness terminating in a flat vertical exterior surface at one vertical side thereof for metal to metal thermal contact with a vertical freeing surface, the bottom and opposite side of said mold being relatively thin and having an exterior surface of substantially the same curvature as that of the semi-cylindrical ice-forming compartments, and a plate heater of substantially the same extent and curvature as that of the exterior of said bottom and opposite side of the mold and placed in thermal contact therewith, the construction and arrangement being such that substantially all heat transferred from the mold passes though the mass of metal to the vertical freezing surface, Whereas, heat transferred to the mold from the heating element heats interior surfaces of the mold compartments without appreciable heat transfer to the vertical freezing surface.

7. An ice mold as set forth in claim 6 wherein a thermal insulating element and an insulation casing, each of substantially the same extent and curvature as that of the exterior of said bottom and opposite side of the mold, are attached to the bottom and opposite side of the mold.

8. A refrigerator having a freezing compartment bound by a refrigerated liner open at the front for access to said compartment, means for cooling at least one side Wall of said liner to sub-freezing temperatures, said liner and said refrigerator being provided with aligned openings in rear walls thereof, a self-contained automatic ice maker insertable as a unit through said rear openings into said freezing compartment for attachment in thermal contact with said one side wall of said refrigerated liner, said ice maker including an open top ice mold divided into a plurality of ice-forming compartments, means for removably attaching said mold to said one side wall of said refrigerated liner in metal to metal contact therewith for cooling thereby, means for filling the mold with water to be frozen, means mounted on the ice maker and movable through the mold for contacting and removing the ice from the mold through the open top thereof. and control means operable responsive to the freezing of ice in the mold for energizing said filling and ice removing means, said mold, said filling means, said ice removing means and said control means being united into a single unit so constructed and arranged as to be readily removable from said freezing compartment as a unit and independently of said refrigerated liner.

9. A refrigerator comprising a thermally insulated cabinet, refrigerating apparatus including a freezing element in the cabinet, and an ice making device including a mold, means for supplying the mold with water to be frozen into ice, means for discharging ice from the mold and control mechanism for causing cyclical operation of said water supply and ice discharging means, said mold, said water supply means, said ice discharging means and said control mechanism being united into a single unit so constructed and arranged as to be readily removable from said cabinet as a unit and independently of said refrigerating apparatus, and said mold being in readily separable thermal association with said freezing element when the ice making device is in the cabinet.

10. A refrigerator comprising a cabinet having a compartment therein formed of an inner liner, an outer shell and thermal insulation therebetween, refrigerating apparatus including a freezing element in said cabinet, and an ice making device including a mold, means for supplying the mold with water to be frozen into ice, ejector means for discharging ice from the mold and control mechanism for causing cyclical operation of said water supply and ejector means, said mold, said water supply means, said ejecting means and said control mechanism being united into a single unit so constructed and arranged as to be readily removable from said cabinet as a unit and independently of said refrigerating apparatus, and said mold being located within the compartment in readily separable thermal association with said freezing element, said water supply means being at least partially located within the insulation between the liner and shell and said ejector means including a power mechanism within the insulation and an ice contact member within the compartment when the ice making device is in the cabinet.

References Cited in the file of this patent UNITED STATES PATENTS 1,788,393 Hull Jan. 13, 1931 2,026,227 Foraker Dec. 31, 1935 2,077,820 Arp Apr. 20, 1937 2,117,929 Watt May 17, 1938 2,161,321 Smith June 6, 1939 2,221,694 Potter Nov. 12, 1940 2,247,903 Brace July 1, 1941 2,259,066 Gaston Oct. 14, 1941 2,269,642 Zerk Jan. 13, 1942 2,356,780 Morrison Aug. 29, 1944 2,364,559 Storer Dec. 5, 1944 2,407,058 Clum Sept. 3, 1946 2,418,572 Brennan Apr. 8, 1947 2,429,851 Swann Oct. 28, 1947 2,435,102 Rundell Jan. 27, 1948 2,656,686 Bayston Oct. 27, 1953 2,682,155 Ayres June 29, 1954 2,685,952 Hamlin Aug. 10, 1954 2,704,927 Carrell Mar. 29, 1955 FOREIGN PATENTS 1,066,201 France June 3, 1954