US2801527A - Ice making apparatus - Google Patents

Description

Aug. 6,1957 R. s. GAUGLER ETAL 2,801,527 ICE MAKING APPARATUS 2 Sheets-Sheet 1 Filed May 23, 1955 2% m wim m m W Z M W a A THEIR ATTORNEY R. s. GAUGLER ETAL Aug. 6, 1957 ICE MAKING APPARATUS 2 Sheets-Sheet 2- Filed May 23, 1955 INVlgNTOR. f 'iard J 622 23? BY 6? .Waier/ 4251 7,

THEIR ATTORNEY United States Patent 9 ICE MAKING APPARATUS Richard S. Gaugler and Robert Galin, Dayton, Ohio, as-

signors to General Motors Corporation, Detroit, Micin, a corporation of Delaware Application May 23, 1955, SerialNo. 510,128

4 Claims. (Cl. 627) The present invention relates to refrigerators and particularly to an automatic means or apparatus for producing and dispensing ice pieces therefrom.

Many attempts have heretofore been made to provide means for freezing water in tubular freezers, ejecting a rod therefrom and severing the rod into short ice rod pieces or pellets to be used in chilling drinks or the like in glasses without requiring any manipulation thereof by the user of the refrigerator. These means have been complex, expensive and difiicult in operation and for several reasons have not, to our knowledge, appeared in commercial use. In most of the prior ice rod or stick producing apparatuses it was necessary to thaw or defrost the ice rod or stick in order to render the same releasable from walls of its tubular freezing mold member before it could be moved relative thereto and ejected therefrom. This thawing or defrosting of the ice stick or rod column in such apparatuses prolongs a subsequent freezing cycle and materially reduces the overall capacity and efliciency of the apparatus. In other prior ice rod or stick producing apparatuses it was necessary to provide the same with an additive pressure increasing means such as a compressed air unit or system to accomplish move ment or ejection of an ice column from its forming or freezing mold and such additive means increased the cost of the apparatus to a point where it was prohibitive to manufacture and sell same. We therefore contemplate the production of an automatic ice making apparatus for producing short rod-like pieces or pellets of ice from a column, stick or rod of ice which is at all times operable at temperatures below 32 F. whereby the freezing portion of the apparatus is rendered capable of being installed within a frozen food storage compartment of a household refrigerator cabinet and wherein water supplied to the apparatus is prevented from. being expelled from the freezing portion thereof unless in a frozen state during the automatic operation.

An object of our invention is to provide an improved method of and a simplified, inexpensive apparatus for automatically making pieces of ice.

Another object of our invention is to provide an automatic device for making and dispensing short rod-like pieces or pellets of ice in a freezing or frozen food storage compartment of a household refrigerator cabinet which is compact and will not occupy too much of the. valuable storage space in the compartment.

A further object of our invention is to provide an ice stick or rod making apparatus from which short rod-like pieces of ice are obtained without defrosting or thawing the ice column prior to moving or ejecting a length thereof from its freezing mold or tube and which apparatus operates automatically and continuously to produce ice pieces so long as a demand therefor exists.

A still further object of our invention is to provide an improved mode of operating an ice rod or stick freezing apparatus, an improved mode of controlling an apparatus of this character and elements thereof and to provide r ce features of construction, combinations of elements and arrangements of parts in an apparatus of this type which renders the same practical and positive in operation.

In carrying out the foregoing objects it is a more specific object of our invention to increase the pressure of water from a source of supply thereof under pressure leading to an ice making apparatus substantially above the pressure in the supply source, to employ this higher pressure water as the sole means of hydraulically breaking a bond between an ice column and inner walls of a freezing tube, as distinguished from warming the tube to thaw the ice column, and to also utilize the normal pressure of water in the supply source thereof for furnishing, without the aid of additional means, the motive power for causing a return stroke of a pumping element in an electric solenoid operated pump or device of the apparatus.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings:

Figure l is a front view of a two temperature household refrigerator cabinet having the ice making apparatus of our invention incorporated in the frozen food storage. compartment thereof;

Figure 2 is an enlarged vertical fragmentary sectional view taken on the line 2-2 of Figure 1 showing the freezing portion of the ice making apparatus in conjunction with a secondary refrigerant circuit associated with a primary evaporator of a refrigerating system associated with the refrigerator cabinet and employed to cool the interior of the food storage compartments thereof;

Figure 3 is an enlarged sectional view of the freezing portion of the ice making apparatus showing its association with a closed refrigerant circuit incorporated in the refrigerator;

Figure 4 is an end view of a solenoid actuated water pump device portion of the ice making apparatus;

Figure 5 is an enlarged sectional view of the water pump device and is taken on the line 55 of Figure 4; and

Figure 6 is a wiring diagram with controls therein for controlling the operation of the ice making apparatus.

Referring to Figure l of the drawings, wherein an embodiment of the invention is shown, It} generally represents a conventional household refrigerator cabinet of the type including an upper insulated freezing or frozen food storage compartment 11, normally closed by a door 12, and an insulated lower unfrozen food storage compartment 13 separate from compartment ll, normally closed by a door 14, which are adapted to be cooled by means of a now Well known or conventional closed refrigeration system. The refrigerating system includes a plate-like evaporator 15 suitably mounted within compartment l3 and a refrigerant evaporator conduit 16, wrapped or coiled around the metal liner 17 of compartment 11 (see Figure 2) in contact therewith. The refrigerating system also includes a motor-cotnpressor, a condenser and suitable pipe or conduit connections (not shown) with the evaporators for circulating refrigerant in succession first through evaporator conduit 16 and thence through the plate-like evaporator 15. Usual or conventional controls would be provided for controlling the operation of the motor-compressor unit, as is well known to those skilled in the art, to normally maintain the temperature of evaporator 16 between l0 and +15 F. and, consequently, the temperature within compartment 11 substantially between 0 and +5 F. while the temperature in compartment 13 is maintained by evaporator 15 at approximately 40 F. t

We have incorporated the ice stick or rod freezing portion of the ice making apparatus of the present invention in conjunction with a refrigerant evaporating section of a closed secondary refrigerant circuit or system which cireuitor system is rendered operative or effective by associating a refrigerant condensing section thereof with the evaporator 16 of the primary refrigerating system above described. For example, the sealed secondary circuit, charged with a suitable volatile refrigerant and inert gas in the well known manner, includes a horizontally elongated conduit condensing portion or section 21 secured in any suitable or desirable fashion to the top wall of liner 17 of compartment 11 so as to be in intimate metal-to-metal contact with the primary evaporator conduits 16. The sealed secondary circuit also includes an upright elongated bulb-shaped refrigerant evaporating portion of section, generally represented by the reference character 22, located in the rear part of frozen food storage compartment 11 and connected by a charge pipe fitting 23 to the portion or section 21 thereof. This secondary refrigerating circuit is of a generally inverted L-shape configuration. Such closed secondary refrigerating circuits or systems are well known to those skilled in the art and refrigerant contained therein evaporates in the portion 22 thereof upon absorbing heat and the evaporated or gaseous refrigerant rises into the section or portion 21 thereof wherein it is cooled and condensed by the refrigerating efiect of the primary evaporator 16 and then returns in liquid form to the section or portion 22 for reevaporation therein. An ice piece or pellet receiving and storing receptacle 24 is located Within compartrnent 11 in front of the ice freezing portion of the secondary refrigerating circuit (see Figures 1 and 2).

Evaporator 22 of the secondary refrigerating system forms a part of the freezing portion of the present ice making apparatus. The freezing portion of the apparatus comprises a substantially cylindrical stainless steel hollow tubular member or tube 26 (see Figure 3) having its inner diameter polished or honed to provide a highly finished or smooth surface thereon. A bulged sleeve 27 having its upper and lower edge portions secured and sealed to tube 26 in any suitable manner provides the refrigerant evaporating chamber 22 of the secondary refrigerating system. The sleeve 27 surrounds tube 26 and forms a means in the secondary refrigerating systemfor cooling the tube and freezing water received therein into ice, 2. portion of which is frozen into a solid column as will be hereinafter described. The tube or tubular member 26 has an upper open end and its lower end is secured to a pipe fitting 28. Tube 26 is approximately four and onehalf inches long and is substantially one-half inch in diameter. An inverted well-like element 29, having its lower end secured to pipe fitting 28, extends upwardly a predetermined distance into the tube 26. The well-like element 29 receives a closed end of a tube 31 which forms a part of a thermostatic unit or control for the apparatus. Pipe fitting 28 is provided with a water passage 32 leading into the lower part of tube 26 remote from its upper open end. One end 33 of a water pipe is secured to the pipe fitting 28 and communicates through passageway 32 with the interior of tube 26. A closed end portion of a tube 34 is secured to the sleeve 27 of the freezing portion of the secondary refrigerating system and this tube 34 forms a part of another thermostatic unit or control for the apparatus. An electric resistance heater element 36, of any suitable or conventional construction for a purpose to be hereinafter described, is secured to a wall portion of sleeve 27 and has wire connections 37 and 38 (see Figure 2) leading therefrom. An angularly shaped metal bracket 39 is secured to the top wall of liner 17 of compartment 11 and extends downwardly therefrom over the open upper end of tube 26. This metal bracket 39 is provided with an aperture 41 located above tube 26 to permit the end of a column of ice formed therein and ejected therefrom to pass through bracket 39 and strike or engage an inclined portion 42 thereof for breaking or severing short rod-like pieces or pellets of ice from the column (see Figures 2 and 3) and for directing or flipping them into receptacle 24. Thermostat tubes 31 and 34, pipe 33 and wires 37 and 38 extend through the insulated back wall of compartment 11 (see Figure 2) to a control box 44 mounted on the rear wall of cabinet 10. The outer end of each of the tubes 31 and 34 is connected to a sealed expansible and contractable member of suitable or conventional snap acting thermostatic switches 36 and 35 (see Figure 6) respectively connected in the electric circuit for the apparatus and housed in box 44. Wires 77 and 78 also extend from the freezing portion of the apparatus into box 44 and are connected in the electric circuit in a manner disclosed in Figure 6 of the drawings for a purpose to be hereinafter described. Pipe 33 is connected to a water operated water pump device also housed in the box 44 and utilized for a purpose to be more fully described hereinafter.

In the present apparatus we provide a water pump device for increasing the pressure of water conducted into the freezing tube 26 substantially above the pressure of water from a source of supply thereof leading to the apparatus which water under the increased pressure comprises the sole means of hydraulically breaking a bond between an ice column in tube 26 and walls of this tube. This device includes a solenoid motor and a valve assembly associated therewith. Referring now to Figure 5 of the drawings, the motor and valve device includes a housing 51 secured to a flange 52 which serves to mount the device on the control box 44. Housing 51 is provided with a hollowed out part which contains a solenoid coil 53 having an armature 54 therein. The solenoid motor armature 54 carries a piston or pumping element 56 which is located in a chamber 57 provided in a pipe fitting 58 secured to housing 51. Chamber or cylinder 57 is approximately three-eighths inch in diameter and the piston or pumping element 56 reciprocates therein throughout a substantially one eighth inch stroke.

Fitting 58 has "a water pipe 59 leading from a city water line or source of water supply under pressure. A check valve 61, interposed between chamber 57 and water supply pipe 59, is pressed upon its seat by a spring 62 located between the valve and piston for pumping element 56. Spring 62 is of such force as to require say, for example, 15 p. s. i. goof water pressure thereagainst to open the check valve 61. A removable or an adjustable restrictor 63 is placed in the water passage between check valve 61 and water supply pipe 59 for regulating the return or repetition of power strokes of the piston 56. The pipe fitting 58 is provided with an outlet port 64 for chamber 57 controlled by another check valve 66. A coil spring 67 is interposed between valve 66 and the water pipe 33 leading to the freezing portion of the apparatus. Spring 67 is of such strength as to make it necessary to apply a pressure of say, for example, 150 p. s. i. g. of water pressure against check valve 66 to open same. Resilient follower finger means 68 is associated with the armature 54 and is attached to a limit switch 69 for operating same. Switch 69 is mounted on a bracket 71 secured to the housing 51 of the solenoid actuated motor and is adapted to be operated by the finger follower means 68 in a manner and for a purpose to be hereinafter described. An opening or openings 72 provided in a wall of housing 51 permits reciprocation of armature 54 relative to solenoid coil 53 without trapping air between the armature and the housing. The switch 69 is connected in the electric circuit of the apparatus in such a manner as to be opened at the end of a pumping stroke of armature 54 and pumping element 56 and to be closed upon a return stroke thereof. A rectifier 73, of the bridge rectifying circuit type, is interposed in the electric circuit of the apparatus (see Figure 6) for converting volt A. C(cufrent into D. C. current whereby the solenoidcoil 53 will be energized to the extent of approximately 400 watts when the switch 69 closes.

Also included in the apparatus is an electric resistance heater 76, of any suitable or conventional construction and of approximately 5. watt capacity, which may be attached to or wrapped around the pipe fitting 28 (see Figure 2). of the freezing portion of the apparatus for warming same and preventing water therein from freezing when ice pellets are not being produced. Wires 77 and 7 8 lead from heater 76 and extend into box 44 wherein they are connected in the electric circuit of the. apparatus as shown in Figure 6 of the drawings. Heater 76 is adapted to be energized and deenergized by a weight actuated switch associated with the ice receiving and storing receptacle 24. This weight switch is of a. construction which includes two stationary contacts. 81 and 82 and. a movable contact 83 for engaging one or the other of the contacts 81 and 82 in response to the Weight of ice contained in receptacle 24.

Operation Assume that the refrigerator cabinet 10 has been installed in a home and the refrigerating systems associated therewith have operated throughout a period of time sufiicient' to reduce the temperature in compartments 11 and 18 to their proper degree and it is now desired to cause Water under pressure to flow from the city main to the ice making apparatus for producing short ice rods, pieces or pellets. The water is turned on and it flows through pipe 59-, restrictor 63, past check valve 61 and into the pumping chamber or cylinder 57 of the solenoid motor operated water pressure increasing means or device of the apparatus. City water pressure is usually above that required toopen check valve 61 and therefore chamber 57 becomes filled and this water pressure forces pump element or piston 56 and the solenoid armature 54, to which it is secured, outwardly with respect to solenoid coil 53. This closes the limit switch 69. If the freezing or frozen food storage compartment 11 is at its proper low temperature of to F. the temperature of freezing tube 26 and that of the thermostat tube 31 will have been reduced to a point between and F. Sufficient to close switch 30 to permit electric current to flow through switch 69 and rectifier 73 to energize solenoid coil 53. Here it is tobe understood that if the freezing portion of the ice making apparatus and particularly thermostat tube 31 should not yet be cold' enough to cause switch 30 to close no current will be conducted through switch 69 and consequently solenoid coil 53 cannot be energized. This insures against water under increased pressure being squirted from the upper open end of tube 26 into compartment 11. However, whenboth switches 30 and169are closed and solenoid coil 53 is energized the armature 54 enters or is drawn into coil 53 with a bang or like a shot and consequently piston 56 moves into chamber 57. At this time check valve 61 remains closed and the pressure of water in chamber 57 is increased substantially above the pressure of water in the water supply source and is forced through port 64 past check valve 66 and into the pipe 33. This movement of armature 54. and consequently piston 56 causes the limit switch69 to open. for momentarily breaking the electric circuit to solenoid coil 53. The pump in the device disclosed is capable of developing a pressure as high as 3,500 .11. s. i'. After piston 56 has completed this one or first pumping stroke water again enters cylinder or chamber 57, past. check valve 61, from the water supply pipe 59 and the pressure. of this city water causes the piston 56 to make a return stroke and to move. armature 54 outwardly of coil 53:. The rate or speed of the return stroke of piston 56 is regulated by a restrictor 63 of predetermined size in accordance with a given city water line pressure to yield approximately twenty-five power strokes per minute on the pump. Thus the pressure of the city water provides the sole means of returning and readying the piston or pumping element 56 for another pumping stroke. The return stroke of piston 56 and consequently armature 54 again closes limit switch 69. to energizecoil 53 and cause another pumping stroke of piston 56. These pulsations of the water pump continue until the water level rises in freezing tube 26 to a point where it will warm thermostat tube 31 whereupon switch 30 will open the electric circuit to switch 69 and prevent operation of the solenoid actuated pump device. The water pump remains idle while the refrigerating effect on tube 26, by the refrigerant evaporating portion of the secondary refrigerating system, continues and causes water pumped into tube 26 to freeze therein in the vicinity of the upper end of the thermostat tube 31. Soon a portion of the body of water in tube 26 will freeze into a solid layer or column suflicient to surround an effective length of the weld 29 and consequently thermostat tube 31 the temperature of tube 31 is again reduced to cause switch 30 to close. This now places the ice making apparatus in condition for prolonged continuous operation in accordance with the demand for ice pieces to be harvested therefrom. The pulsations of the water pump as described continue and the increased water pressure created thereby beneath the solid column of ice in tube 26 serves the sole means of breaking a bond between the column of ice and walls of tube 26 for shifting the ice column upwardly in tube 26 and a portion thereof out of the open end of the freezing tube. The ice column dislodging operation occurs in short rapid bursts corresponding ap-' proximately to one-sixteenth inch movement thereof for each power pulse of the pump device. The end of the portion of the ice column ejected from tube 26 passes through the hole or aperture 41 in metal bracket 39 and engages the inclined surface 42 of this bracket. A subsequent pulsation of the water pump and consequently a further rise of the ice column relative to tube 26 will cause portion &2 of bracket 39 to sever or break off a short piece or pellet of ice which will be directed by the bracket into the receiving and storing receptacle 24. The column of ice. continues, under the pulsations of the sole noid pump device, to rise in and be ejected from freezing tube 26 and to be broken into short pieces or pellets until the storage receptacle. becomes filled. The weight of the ice filled receptacle 24 then actuates the movable switch contact 83 away from contact 82 and into engagement with contact 81. This opens the electric circuit to limit switch 69 and stops the operation of the water pressure increasing pump device and simultaneously closes an electric circuit from one power main to wire 78, heater 76 and wire 77 to the other power main to energize the electric resistance heater 76. During such times of idleness of the pump device, when there is no demand for ice pellets, the heater 76 warms the pipe fitting 28 and prevents water therein and adjacent thereto from freezing. Obviously, water freezing in the hydraulic path of water flow in the vicinity of the freezing portion of the ice maker, other than that portion thereof surrounded by the evaporator 22 of the secondary refrigerating system, when an adequate supply of ice pellets is on hand is undesirable. Thus, heater 76 protects the apparatus at this time and its effectiveness is not needed during continuous introduction of water to the freezing portion thereof since this incoming water is warm enough to prevent its being frozen in the hydraulic path of water How.

The heater 36 is merely a safety device for the apparatus as distinguished from utilizing artificial heat to thaw or defrost the ice column from walls of the tubular freezing mold 26. Heater 36 is energized only when an abnormal demand for refrigeration occurs in the freezing or frozen food compartment 11. For example, should the user place a plurality of warm packages of food in compartment 11 to be frozen the temperature of evaporator 16 and consequently the evaporator 22 of the secondary refrigerating system will be reduced to such a degree that the ice column ejecting pressures required to move a column of ice in tube 26 would become prohibitively high. This factor is a quality of the surface finish that can be applied to the inner face of freezing tube 26. In the present apparatus, this low critical temperature of stainless steel tube 26, during freezing of foods in compartment ll, has been found to be in the neighborhood of F. Thermostat 34- and switch 35 are ineffective above 10 P. so long as ice pellets are being produced in the freezing portion of the ice making apparatus because the water incoming thereto normally prevents the temperature of the secondary evaporator 22 and consequently tube 26 from being lowered to the critical point of 10 F. However, if no ice is being produced at the time a plurality of Warm food packages are placed into compartment 11 the temperature of thermostat tube 34 and consequently tube 26 will drop below 10 F. and switch 35 will open the electric circuit to solenoid motor switch 69 and will complete a circuit through wires 37 and 38 to heater 36. Thus, the pump of the water pressure increasing device is inoperative while heater 36 is effective to warm the evaporator 22 of the secondary refrigerating system under abnormal demands for refrigeration in compartment ll. It is again desired to emphasize that heater 36 merely warms evaporator 22 to maintain the temperature of tube 26 at or slightly above 10 F. and is not employed for thawing or defrosting the ice column since the apparatus is designed so as to at all times maintain tube 26 below 32 F. for making ice without increasing its temperature above freezing. The feature of the safety device disclosed is to eliminate stalling of the Water pressure increasing pump and possible damage to parts of the ice making apparatus. The device comprising heater 36 and switch 35 is an appendent to the apparatus disclosed and may be eliminated Without departing from the spirit of our invention depending upon the quality of the surface finish to be obtained on the inner face of freezing mold or tube 26. In Other words, if a perfectly smooth and less ice adhesive inner surface on tube 26 can be obtained so that the column of ice will be shifted upwardly at the pressures developed by the present pump at the lowest temperatures encountered in the operation of a refrigerator of the type disclosed there will be no need for such a safety device and, consequently, the cost of the apparatus can be materially reduced. It is to be understood that the banging of solenoid motor armature 54 may be quieted by a suitable rubber or the like washer or shock absorbing pad interposed between the flanged part of armature 54 and the coil windings of solenoid 53. It is to be further understood that by increasing the length of well 29, located Within freezing mold or tube 26, to a point near the upper end of tube 26 short pieces of ice having a hole extending therethrough can be produced from the present apparatus. Ice pieces or rods having a hole therethrough will afford quicker cooling of beverages in glasses since the beverage will have contact with more surfaces of the ice pieces.

From the foregoing, it should be apparent that we have provided an improved ice making apparatus of the type wherein a column of ice is ejected from a freezing tube and broken into short pieces of ice. The improved apparatus operates at all times below the freezing temperature of Water to thus eliminate loss in efficiency occurring due to necessity of thawing or defrosting a column of ice from walls of its tubular mold. Movement of the ice column in the present apparatus is obtained in short rapid bursts without defrosting and solely by increasing the presure of Water leading to the freezing portion thereof. This eliminates the use of other means for increasing the pressure of another or secondary medium employed for ejecting the ice column, and insures fast ice production in that the apparatus does not have to await expansion of the lower portion of an ice column against a body of water therebelow to move same. The incoming water to the apparatus is also utilized in the present apparatus to provide the sole motive power of causing a return stroke of the pumping element of the water pressure increasing means. By our invention a greatly simpli- 8 fied and low cost icemaking apparatus which is compact and which occupies a minimum of space in a freezing compartment of a refrigerator cabinet is provided.

While the form of embodiment of the invention. as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, as may come within the scope of the claims which follow.

What is claimed is as follows.

1. In an ice making apparatus, a source of water supply therefor, a member having an open end and adapted to receive water at a point remote from. its said open end, means for cooling said member to a predetermined water freezing temperature to freeze water received therein into ice a portion of which is a frozen column, a pumping device interposed in said water supply source in advance of said member, means for operating said pumping device to increase the pressure of water above that in said source thereof and to force the water under said increased pressure into said member beneath the column of ice therein, means actuated in response to the formation of said column of ice in said member for controlling said pumping device operating means, said water under said increased pressure providing the sole means of breaking a bond between said ice column and wall surfaces of said member while the member is maintained at said predetermined water freezing temperature for shifting a portion of said ice column out of its open end, and means separate from and independent of said ice formation responsive means actuated by a decrease in temperature of said member substantially below said predetermined water freezing temperature thereof for rendering said pumping device control means ineffective.

2. An apparatus as defined by claim 1 wherein the ice formation responsive means and the pumping device control means are both rendered ineffective automatically in response to a predetermined accumulation of ice produced by the apparatus.

3. In an ice making apparatus, a source of water supply therefor, a cylindrical tubular member having an open end and adapted to receive water at a point remote from its said open end, means for cooling said tubular mem her to a temperature well below 32 F. to freeze Water received therein into ice a portion of which is a frozen column, said tubular member being of uniform internal diameter from the point water is frozen therein into said column of ice to its open end, a pumping device interposed in said water supply source in advance of said tubular member, means for operating said pumping device to increase the pressure of water above that in said source thereof and to force the water under said increased pressure into the tubular member beneath the column of ice therein, thermostatic means actuated in response to the formation of said column of ice in said member for controlling said pumping device operating means, said water under said increased pressure breaking a bond between said ice column and Wall surfaces of said cylindrical tubular member while the member is at said below water freezing temperature for shifting a portion of said ice column out of its open end, and a thermostatic switch responsive to a decrease in temperature of said tubular member to approximately 10 F. for rendering said thermostatic means ineffective to control said pumping device operating means.

4. In combination, a household refrigerator cabinet provided with a frozen food storage compartment, an unfrozen food storage compartment and an ice making apparatus, said ice'making apparatus including a tubular member within said frozen food compartment having an open end and adapted to receive water at a point remote from its said open end, a source of water supply for said tubular member, a refrigerating system associated with said cabinet including means for cooling said frozen food compartment to a below freezing temperature, meansfor cooling said unfrozen food compartment to a temperature above freezing and means for cooling said tubular member to a temperature well below 32 F. to freeze water received therein into ice a portion of which is a frozen column, a pumping device outside said cabinet and interposed in said water supply source in advance of said tubular member, means for operating said pumping device to increase the pressure of water above that in said source thereof and to force the water under said increased pressure into the tubular member beneath the column of ice therein, thermostatic means isolated from the temperature within said frozen food compartment and actuated in response to the formation of said column of ice in said tubular member for controlling said pumping device operating means, said water under said increased pressure breaking a bond between said ice column and Wall surfaces of said tubular member while the member is at said below Water freezing temperature for shifting a portion of said ice column out of its open end into said frozen food compartment, and a thermostatic switch responsive to a decrease in temperature of said tubular member to approximately 10 F. for rendering said thermostatic means ineffective to control said pumping device operating means.

References Cited in the file of this patent UNITED STATES PATENTS Mufiiy Jan. 31, Hamilton Aug. 18, Storer Dec. 5, Hill May 1, Bohn June 24, Bayston Feb. 20, Leeson Apr. 17, Lee May 6, Lee May 20, Van Ryan Feb. 10, Watt May 26, Sunden Apr. 5, Knerr Sept. 13, Lees Sept. 25,

FOREIGN PATENTS France Sept. 29,

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