US2941379A - Ice making apparatus - Google Patents

Description

June 2 l, 1960 J. K. NELSON I 2,941,379

ICE MAKING APPARATUS Filed June 5, 1957 4 Sheets-Sheet 1 e3 2 I 5 24 ,2 '9 6 t m a A l I Z 5| 24 g l9 FIGZ, .1 ii 7 I is 52 I7 I i i{} 29 4| 9 F6 35 I I9 so INVENTOR '9 JAMES K.NE sow I9 20 I9 28 i TI FIGB. FIG.4. 5% @1547 AT OR 4 Sheets-Sheet 2 Filed June 5. 1957 I NVENTOR JAMES K.NELSON 279 H4 ATTORNEY June 21, 1960 J. K. NELSON 2,941,379

ICE MAKING APPARATUS Filed June 5, 1957 4 Sheets-Sheet 3 I N VENTO R JAM ES K. NELSON AT TOR EY June 21, 1960 ,J. K. NELSON ICE MAKING APPARATUS 4 Sheets-Sheet 4 Filed June 5, 1957 INVENTOR JAMES K.NELSON ATT NEY P Patented June 21, 1960 ICE MAKING APPARATUS James K. Nelson, Grove City, Ohio,

house Electric Corporation, poration of Pennsylvania Filed June 5, 1957, Ser. No. 663,711

14 Claims. (Cl. 62-435) assign'or to Westing- East Pittsburgh, Pa., a cor- This invention relates to ice making apparatus, and more particularly to automatic ice makers of the type associated with domestic refrigerators for the production of ice pieces for household use.

This invention provides an improved power unit for ice makers of the type wherein water is frozen in a mold and frozen contents of the mold are removed or ejected by mechanical means. The invention is particularly applicable to flexible mold type ice makers such as are described and claimed in my copending application Serial No. 566,582 filed February 20, 1956, and entitled Ice Maker, and in an application of Meigs W. Newberry, Serial No. 660,856, filed May 22, 1957, and entitled Ice Maker, both assigned to the same assignee as this invention.

This invention contemplates the utilization of a thermal motor in producing forces for actuation of theice making and removing mechanism. The thermal motor preferably takes the form of a confined substance capable of undergoing substantial volumetric changes when subjected to a change in temperature and wherein this change in Volume is utilized to actuate a movable member, such as a plunger. Movement of this member is transmitted to the ice mold portion of the apparatus by unique and novel motion transmitting mechanisms which are hereinafter described in greater detail.

In accordance :with this invention, the thermal motor is so constructed as to function as a temperature-sensitive controller for governing its own actions. Heat is applied to the thermal motor to produce powered motion of its movable member for the purpose of performing the work of removing ice from the mold portion of the ice maker. A quantity of heat is stored in the thermal motor during this period which is subsequently removed by the same refrigerating means employed to cool and congeal the contents of the ice mold. The thermal system of the thermal motor is analogous to the thermal system of the ice mold and its contents and, inasmuch as they are subjected to the same refrigerating effect, the rates at which they are cooled are analogous, and the temperature of the thermal motor is analogous to the condition of the contents of the ice mold. The temperature of the thermal motor is reflected by the position of the movable member associated therewith and, by providing means for sensing the position of this member, certain appropriate bases are established for control of the ice making apparatus. Using these bases for control, the thermal motor is energized and deenergized at appropriate intervals to repetitively remove'the frozen contents of the ice mold and refill the mold following completion of each ice freezing operation of the apparatus.

In many respects, the thermal motor is employed in this invention as an analog control of the type disclosed and claimed in my copending application, Serial No. 643,193 filed February 28, 1957, entitled Ice Maker Control, and this invention is an improvement over the inven- .tion disclosed in that applicatio Other novel features, objects and advantages of the invention will appear in the following detailed description, of which the accompanying drawings form a part and wherein:

Fig. 1 is a vertical sectional view through the freezing unit of a domestic refrigerator embodying an ice maker constructed in accordance with this invention;

Fig. 2 is an enlarged plan view of the ice maker shown in Fig. 1 but with the cover of the power mechanism removed to show the interior thereof;

Fig. 3 is a fragmentary sectional view of the mold portion of the ice maker illustrating the manner in which ice is freed from the mold;

Fig. 4 is a sectional view through the ice mold taken generally as indicated by the line IV-IV in Fig. 3 and illustrating the manner in which ice is removed from the mold;

Fig. 5 is a fragmentary perspective view of the ice maker power mechanism with portions broken away to show the construction of the thermal motor employed therein;

Fig. 6 is a schematic illustration of the power train shown in Fig. 5;

Fig. 7 is an electrical and water circuit diagram for the ice maker and in which portions of the ice maker are illustrated schematically;

Fig. 8 is a diagrammatic illustration of the cycle of operation of the ice maker illustrated in Figs. 1 through 7;

Fig. 9 is a plan view of another ice maker embodying a modification of this invention;

Fig. 10 is an enlarged front elevational view of the ice mold portion of the ice maker shown in Fig. 9 and illustrates the manner in which ice is removed from this mold;

Fig. 11 is a perspective view of the ice maker shown in Fig. 9 with portions broken away to illustrate the construction of the power mechanism including the thermal motor;

Fig. 12 is a detailed illustration of a one-way clutch employed in the power train illustrated in Fig. 11; and

Fig. 13 is an electrical and water circuit diagram for the ice maker shown in Figs. 9 through 12, and wherein certain elements of the ice maker are illustrated schematically.

General arrangement The general arrangement of a domestic type ice'maker embodying this invention is illustrated in Figs. 1 and 2 in which the numeral 15 indicates, generally, an insulated refrigerator cabinet having a door 16 closing the front thereof. Only the upper portion of the cabinet 15 is illustrated and, as in many conventional domestic refrigerators, this portion of the cabinet contains a refrigcrating unit 17 defining a freezer chamber 18. The refrigerator unit 17 includes a plurality of conduits 19 through which refrigerant is circulated to maintain a temperature within the freezer chamber 18 below the freezing point of water and generally at about 0 F. The refrigerating unit 17 is open at its front side to permit access to the freezing chamber 18 and a door 21 is provided for closing this access opening.

The automatic ice maker is disposed within the freezing chamber 18 and consists of several major components, including: An ice making and harvesting mechanism 22; a power mechanism 23 for driving the ice making and harvesting mechanism; a storage container 24 for receiving and storing the manufactured ice pieces; and a water filling system, of which only a filling tube 26 is shown in Figs. 1 and 12.

Ice making and harvesting mechainsm The ice making and harvesting mechanism 22 illustrat 3 ed inFigs. '1 through '4 is of the type invented by Meigs W."N'ewberry"and'described more fully and claimed in his aforementioned patent application, Serial No. 660,856,

filed May 22, 1957. This mechanism '22 includes a mom) made up of a'plurality of serially connected arcuate pockets '28 adapted to receive water to be congealed into'ice. The mold pockets 28 are refrigerated by.a serpentine extension of the refrigerant conduit 19 which is bonded to center line portions 'of'the bottoms of the "mold pockets; The pockets 2 8 are constructed of a resilientmaterial having good heat conducting properties, such as for example, berylliumcopper, and are lsuspended'from the upper wall of theqrefrigerating unit 17 by a resilient U-shaped bracket 29 whichpermits the mold 2710 be longitudinally stretche'dor lengthened to spread apart or 'distend the walls of each' mold pocket 28 for. the purpose of freeing ice pieces frozen :therein.

"Mounted above the "mold '27, and likewise-supported by'the bracket 29, is an ice removing device comprising 'a"plurality of'fingers 32secured'to a rotatable'shaft, 3'3 journalled in the bracket 29. The shaft 33 is preferably mounted directly abovethe longitudinal center'line of the "mold 27 "and' the fingers 32'arel fixed at spaced intervals'thereonin positions 'whichpermit each finger 32 to be swept through a mold pocket 28 when the shaft 33 is'rotated. The shaft 33 also carries,for, rotation therewith, a mold distending cam 34 positioned" to, cooperate withabearingbutton 35 fixed to the mold support bracket29 in a manner to effect a longitudinal stretching of the mold 27 each time the shaft 33 is moved through one complete revolution.

These elements of the ice'making and harvesting mechlanisms'are arranged so that, whenitheshaft 33 is rotated through one. revolution (counterclockwise pas viewed from the front, see Fig. 4) from'andlba'ck to the position shown in Figs. 1 "and 2, the cam 34 longitudinally stretches the mold 27 in a manner toopen'up the walls "of-the mold pockets28" to free the ice pieces therefrom, (see Figf3), the fingers32 thereafter sweep through the moldpockets28 to push the freed ice pieces out of the pockets and permit them to fall by ,gravity into the storage" container 24, and "the mold '27 is thereafter, returned *toits shortened condition.

"Power mechanism 7 The shaft 33 of the ice making and harvesting'mechamsm is driven bythe power.-mechanism 23, shown most clearly in Figs. '2, and 6. The power mechanism 23 tsprferably enclosed in= a'- housing-41 positioned at the rear of the 'ice'making and harvesting mechanism' and rigidly mounted 'toi the rear leg of' supporting bracket 129: and the rear wall of the refrigerating unit 17.

'Powerfor actuating the ice-making and harvesting 'rnecha'nism'is derived from a thermal," or-heat, motor, designatedgenerally by the numeral 42, and disposed within thehousing 41. 'In its preferred form, as shown in Fig. "5, the thermal motor '42 comprises a sealed container '43 enclosing an expansible-contractible "material or'substance 44 'capableof undergoing a substantial volumetric'change, usually accompanied by' a change of state, when subjected to a change in-temperature. Substances-of this nature are referred toas'being morphologically transformable. 'In' this instance a substance, suchas acombination of paradichlorobenzene and cyclohexane which will undergo. avolumetric change Within the-temperature range of 20 F. to 45 F., is employed. Thecontainer- 43 has an "opening in one end wall thereof cdlbyii a *wall '51 constructed of heat insulating "material indicated at 54. For reasons which will become apparent hereinafter, that portion of the housing 4'1 which contains the thermal motor 42 is -preferably lined or covered with a heat insulating material as indicated at 56.

The thermal .motor 42 is energized by the electric heating element 52 which raises the temperature of the expansible-contractible; material A4, :causing it to expand and exert a constricting pressure or force around the flexible sleeve 46. When thus squeezed, the sleeve 46 urges the tapered plunger 47 out its openlend with considerable force thatthe plunger transmits to the slide 48. When the heater 52 is deenergized and the, temperature of the eXpansible-contractible material 44 is reduced by virtue of the thermal motor 42 being refrigerated by a pass of the refrigerant conduit19 arranged inheat exchange relationship with the lower surface. of the housing 41 (see'Fig. 1), .the material 44 contracts and the plunger '47 is moved back into the sleeve 46 as the sleeve is permitted to expand. The thermal motor 42 is constructed to force its plunger 47 to a fully extended position when the temperature of the motor reaches an upper predetermined value or limit of approximately 45 "F., and to fully retract its plunger when its temperature is lowered to a lower predetermined value or limit of the order of 20 F. Thermal motors constructed in the manner described above are capable ofproducing'forces of the order of 400 pounds over approximately a'half inch rangeof movement of the plunger 47.

This'forceful, limited movement of, the plunger 47, is transferred into forces and movements capableof actuating the ice making and harvesting mechanism 22 by means of a power train positioned within the power mechanism housing 41. j Referring to Figs. 2and5, the slide 48 carries a roller 57 which engages one edge of an oscillating beam 58 supported for pivotal movement about itslower end by a' shaft 59. The opposite edge of the beam 58 is adapted toengage aroller 61 on a crankshaft 62 mounted for rotating movement (clock wise as viewed in Fig. 5) within the housing 41 about anaxis disposed above and substantially parallel to the pivotal, axis ofjthe beam supporting shaft 59. This power trjain employs the oscillating beam 58 as a thirdclass lever to transform the short reciprocating movements of theislider 48 into more pronounced rotary movements of the crankshaft p62. The crankshaft 62 is biased through itsjdead center positions with respect to the oscillating beam 58 by means of a tension spring 63 ,having one end'thereof secured to the throw portion of the crankshaft and the other endthereof to a stationary support 60 on, the far end wallrof the housing 41 (Fig. 2).

Fig. 6 illustrates schematically the dead center positions of the linkage and the positioning of thespring 63 which enables it to pull the crankshaft-through these positions. As is believed to be apparent from this diagram, inorder for the spring 63 to be effective in biasing the crank 62 through both of its dead center positions (indicated at A and B), the pointof securement '60 ofthelstationary end of the spring 63 must bellocated somewhere within the acute angle .a betweenplanes C and D, passing through the; pi votal axis of the crank ,and,; respectively,'through the longitudinalaxis of the crank arm inits two dead center positions with respect to the beam 58.

"Inadditionto preventing the crankshaft 62 frombecoming locked on dead centerv withthe beam '58,"t l 1e spring 63 also assists in returning-the'thermal motor plunger 47 to the interior of sleeve 46 by pulling the beam 58 through the return portion of its movement.

The crankshaft 62 carries a cam 66 for actuation of an electric switch 67 mounted within the power mechanism casing 41. The forward end of the crankshaft 62 is coupled directly to the shaft 33 of the ice making and harvesting mechanism for driving the fingers 32 and the mold-distending cam 34.

Electrical and water-systems As illustrated in Fig. 7, the switch 67 controls ener gization of the thermal motor 42 and a solenoid-actuated three-way water valve 71. The electrical circuit includes a source of electrical current indicated at L and L and a manually actuated on-oif switch 72 by means of which the ice maker can be turned off. When switch 67 is closed, the heating element 52 of the thermal motor 42 .is energized through the leads 53 and the solenoid valve 71 is also energized. When switch 67 is open, the heating element for the motor 42 is deenergized and the valve 71 is dcenengized.

Water is conveyed to the automatic ice maker from a supply conduit 70 to the valve 71 which, when energized, connects the supply conduit to a water measuring chamber 73 having a flexible wall 74 capable of being flexed outwardly against the action of a spring load plunger 76 by the pressure of water entering the chamber 73. When valve 71 is deenergized, it connects chamber 73 with the mold filling conduit 26, and the measured quantity of water in chamber 73 is forced therefrom by the plunger 76, flows through filling conduit 26, and into the mold 27 Referring to Figs. 5, 6 and 7, the switch actuating cam 66 is so constructed and mounted on the crankshaft 62 as to close switch 67 just as the slider 48 reaches its most retracted position, as produced by cooling of the expansible and contractible material 44 within the thermal motor 42. This position of the power train mechanism coincides with a dead center position A of the crankshaft 62-beam 58 combination and, in this position, the spring 63 rapidly moves the crankshaft 62 through its dead center position and effects abrupt, positive actuation of the switch 67 to its closed position. The elements of the ice making and removing mechanism are so constructed and arranged that, as the switch 67 is closed by the cam 66, the rise portion of the cam 34 is about to engage the pressure button 35 whereby continued rotation of the crankshaft 62 and shaft 33 will cause an elongation of the mold 27. The fingers 32 are arranged on the shaft 33 in such a manner that they effectively lag the rise portion of cam 34 by 90, i.e., the fingers 32 are positioned to be brought into engagement with the ice pieces in the ice mold 27 by a further 90 rotative movement of the shaft 33 after the switch 67 is closed and the rise portion of the cam 34 encounters the pressure button 35. This relationship enables the full power available from the power mechanism 23 to be devoted to spreading the walls of the mold pockets 28 for the purposeof loosening the ice before the fingers 32 are swept through the pockets. 28 to remove the ice.

The cam 66 is further constructed and arranged to open switch 67 when the sleeve 48 nears its most extended position as produced by heating of the thermal motor 42. This is the dead center position B for the crankshaft 62-beam 58 combination and again the spring 63 rapidly moves the crank 62 through this position to produce positive actuation of the switch 67. The switch 67 is opened as the ice removing fingers 32 are moved through and beyond the ice pockets 28 and the rise portion of cam 34 is moved out of engagement with the pressure button 35 to permit the mold 27 to return to a shortened condition preparatory to receiving a fresh supply of water.

Operation Assume the mold pockets 28 of the ice maker are filled with ice which has just become frozen; in other words, the refrigerant conduit 19 has cooled the mold 27 to a temperature below freezing. In accordance with this invention, the power mechanism 23 will, at this time, also have been refrigerated to the predetermined temperature (approximately 20 F.) at which the thermal motor 42 has moved the power train to the position in which switch 67 is closed by the cam 66.

The closing of switch 67 initiates an ice removing operation of the ice maker which commences with the energization of the thermal motor heater 52. The solenoid valve 71 is simultaneously energized to admit water to the measuring chamber 73. As the expandable-contractible material 44 in the thermal motor 42 is heated it expands, moving the plunger 47 and the slide 48 to cause rotation of the crankshaft 62. As the crankshaft 62 and shaft 33 are rotated, the mold 27 is distended by the cam 34 and the ice pieces are loosened from their respective mold pockets 28 as the walls of these pockets are spread apart (see Fig. 3). Continued rotation of the shaft 33 under action of the thermal motor 42 swings the ice removal fingers 32 through the mold pockets 28, sweeping the ice pieces therefrom. The heat motor 42 continues to cause rotation of the crankshaft 62 until the cam 66 actuates switch 67 to its off position, deenergizing the thermal motor heater 52 and the solenoid valve 71. A measured quantity of fresh water then flows from the measuring chamber 73 to the filling conduit 26 and into the pockets of the ice mold 27.

The refrigerant flowing through conduit 19 extracts heat from the mold 27 and the freezing of ice in the mold pockets commences. This same refrigerating means also extracts heat from the thermal motor 42 by virtue of its contact with the bottom wall of the power mechanism housing 41. The thermal system of the thermal motor 42, including the heat storage mass 54, possesses a certain quantity of both latent and specific heat imparted thereto by the electrical heater 52. The insulating jacket 56 surrounding the thermal motor 42 is so designed that the rate at which this heat is extracted from the thermal motor 42 is analogous to the rate at which heat is extracted from the ice mold 27. Since the ice mold 27 and the thermal motor 42 are subjected to substantially the same refrigerating effect from the refrigerant conduit 19, the thermal motor 42 will have its temperature reduced to a predetermined value in the same period of time required to freeze the contents of the mold 27, regardless of changes in the refrigerating effect available from the refrigerant conduit 19. This predetermined temperature value is made to coincide with the temperature of the thermal motor at which the plunger 47 and slide 48 assume their most retracted positions. This temperature value of the thermal motor 42 is preferably of the order of 20 F.

The upper and lower limits of temperature between which the thermal motor 42 is cycled, and which may be 45 F. and 20 F., respectively, need not coincide with the upper and lower temperature values between which the ice mold 27 cycles, the latter being of the order of 55 and 30 F., respectively.

The thickness and conductivity of the insulation 56 surrounding the thermal motor 42 is preferably chosen such that the thermal motor 42 will be cooled to the temperature at which switch 67 is closed in a slightly greater period of time than is normally required to freeze ice in the mold 27. This excess time allows a safety factor to compensate for variables affecting freezing time, such as variations in the temperature of the water admitted to the ice mold 27.

During the period ice is being formed in the mold 27 and the thermal motor 42 is cooling, the ice removal fingers 32 are rotated in the free space above the ice mold 27 and their movement in no way interferes with 7 the freezing of ice in the rr old. The cam 34 is also rotated during this period and is provided with a dwell area which does not move the mold 27 (see F g; --8). Modified ice making and removing mechanism Figs. 9-through 13 illustrate a modified power mechanism constructed in accordance with this invention and applied to a different type of ice making and removing mechanism. Elements common to this apparatus and the previously described embodiment are identified by like reference numerals. In this apparatus iceis formed in a trough-like flexible mold'81 supportedfor movement toward and away from a heat conducting .support 82 mounted on the side wall of a refrigerating unit 83. '-The mold 81 is carried by front and rear pivot plates, indicated respectively at 84 and 85, whichalfe independently, pivotally attached to the supported 82.

The plates 84 and-85 support the mold :81 forswinging movement about one longitudinal edge ofthe'mold and the front plate 84 carries a stop pin :86 engageable with the support 82 for limiting .movement of 'theforward end of the mold ,81. :The rear pivotplate .85 is rotatable by a shaft 87 through an angle greaterthan the forward pivot plate 84 is permitted to -turn .for the purpose of lifting the mold81-from its support 82 and imparting to the mold a twist when it is partially inverted to loosen and eject ice therefrom. The action of the mold 81 in releasing ice is. illustratedin Fig. 10. Ice pieces leaving the mold 81 fall into aremovable storage tray, indicatedat 88, in Fig. 9. The mold 81 is filled with water by means of-a fill. conduit 26 when it is in an upright position and resting on the support 82. This ice making and removing mechanism is described .more fully and claimed in my previously-mentioned copending application, .Serial .No. 566,582 filed .February20, 1956.

Modified power mechanism An oscillating motion is intermittently imparted. to the drive shaft-87 of the ice making and removing mechanism by-rneans of a power mechanism 91 ;dispo sed within a housing 92 disposed rearwardly of the ice mold 81 and mounted ingood heat-exchange relationship with the refrigerating unit 83. As shown-most clearlyin 'Fig. 11 the power mechanism ,91 .employsathermalmotor 42 identical to thethermal motor previously-described with reference to the first embodiment of theinvention. In this modified power mechanism, however, .the. thermal motor plunger 47 is connected toca slider;93.havinga gear rack 94 on its under surface. ,Reciprocatingmoyernent of the rack 94, as-produced by the .thermaLmotorAZ is transmitted to apinion 9 6 connected; bymeans of a one-way clutch 97 (see Fig. 12), to. a shaft,98journa1led in the housing 92. The clutch 97 -is so constructed-as to transmit onlyclockwise rotativernovementi as vuiewed in Figs. 11 and 12) to the ShaftyQS. Consequently, only the power movement of they slider. 93, as caused by energization of the thermal motor 42, is transferred to the shaft-98, and movementof the slider, 93 produced-by cooling of the thermal motor 42 produces no rotationof the shaft 98.

Intermittent unidirectional rotation of the. shaft -98 is transmitted by a large gear 99 thereon-to .a, smaller gear 101 for rotation, at an increased speed, of a shaft 102 carried in bearing supports 103 on the wall. of the housing 92. Rotative movementof the shaft 102 .is transmitted by a crank 164 on the end of the shaft toa slotted oscillating beatnltld by acrankpin 107riding inthe slot of beam 106. The slotted beam l 6isaifixed to one end of the power shaft 87 and its oscillatingmotionistransmitted therethrough to the end of the mold 8 1. i

The gear and lever. elements of the. power mechanism 91 are so proportioned as to movethermoldfsupport plate 85 from a substantiallyhorizontal position which std position illustrated in Fig. 10 and backlo a horizontal.

As in the previously described embodiment of the invention, energiza-tion ofthe heat motor 42 and a solenoid valve 71 is controlled by a switch 67 actuated by means which are connected to, and reflect the positionofl the slider 93. The position of the slider 93 isfin turn, determined by the temperature of th'e thermal motor Thecifcuit for these" elements isshowri in Fig. 131 The switch 67' is mounted in a positiontobe actuated by'a pair of up's tanding lugs .108'and 109 an slider The arrangement is suchiithfat' slider lug108opens switch 67 as the slider 93 nea s the jets or its range r movement when'l'aeilig propelled .outwardly ,hy'the thermal motor 42; The snder lug metastases switchf67 t -c'lds 'a position when the slider" 93 nears the et er itsfran' ge of reverse movement as occasioned by cooling .ofthe thermal'rnotor 42. i i

When closed; switch 67 connects supply lines L and-L to the heat f g v 'elerner'itofthethermal motor 42, initiating powered operation of the thermal motor, and also v"energizes" the solenoid valve 7 1It'o admit water-from supply conduit into water measuring chamber 73. When opened, switch'67 effects deener'gization of the thermal motor heater 52 and deene'rgiz ation of me sianoid valiie 71 permitting water'.to'flow from, the mealsuring chamber "73,through filli duit 'zsf nip' the mq 8e1- Operationof modified ice maker of Figs. 9-13 Completion of the freezing operation of the contents ofithe mold 81 is accompanied by coolingof'the'the mal motor 42 to a temperature which causes the slider j9i3.,to moveits lug 109 to" a positiontoclose switch 67." ,Ener gization of the thermal motor 42 by, the switch 67 6 f s es theexpansible-contractible material 44 in'th'et rnial motor 42 to expand and force the plunger 47 and Slider 93 outwardly, away-from the motor '42. -Moveinen'ti'of the slider 93 is transferred'throu'gh rack 94 and, pinion 9 6 to'shaft' 98, through geartrainsa ltllland' shafi' loz to crank 104 which oscillates beam 106 and moldpivjot lplate to lift the mold-81 away from support 82, twist the mold 81 to remevei e therefrom, and returnftlie mold'sl to its support 82'. Asjthejs'lider as: ears :jih'e end of its'oiitwa'rd movement; the liig108 comesin contact with andopensswitch 67. Thetherm'al'niotorheater 52 is deenergi'zed-and the solenoid valve 71 1isjde1e d admitting water to the'mold s1. "j

The thermal system of thethermal motor 42, as in the previously described embodiment,"is analogous tothe thermal system of the icemold 81. and'itsi content's, such that the time required to cool the thermal inotor 4216a temperature where the switch 67 is again. closed is the same'as, or slightly greater than, the time requiredito completely freeie the contents of the mol'd 81. The ice maker will automatically repeat the ice removing operation unless the'line switch 72 is manually opened i From the foregoing, it will be apparentlhi s'invention provides an improved power mechanism or drive arrangement for automatic ice makers wherein a thermal motor is employed both as a source of motive power and a'sa cont'rollerfor itself and other elements of the ice' making apparatus." While a thermal motor employing a confined, expandable-contractible substance is herein 1 de scribed, and is preferred for this application, .it istov be understood thatother thermo-motive devices, such asyffir e amp t o-s n t v im t mbe nsa sb m o e in practicin t inyg is While the invention has been shown in seyeral forms,

it Will-:be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications without departing from the spirit thereof.

What is claimed is:

1. In an ice maker, an ice mold, means for removing the frozen contents from said mold, a thermal motor for driving said removing means, means for refrigerating said ice mold and said thermal motor, and means actuated by said thermal motor upon being refrigerated to a predetermined temperature for energizing said thermal motor.

2. In an ice maker, an ice mold, means for filling said mold with Water to be frozen, means including a thermal motor for removing the frozen contents from said mold, means for refrigerating said ice mold and said thermal motor, means for heating said thermal motor, and means responsive to said thermal motor being refrigerated to a predetermined temperature for energizing said heating means. I

3. In an ice maker, an ice mold, means for removing the frozen contents from said mold, a thermal motor adapted upon being heated from a first predetermined temperature to a second predetermined temperature to drive said removing means to effect removal of the contents of said mold, means for refrigerating said mold and said thermal motor, means for heating said thermal motor, and means responsive to said thermal motor being cooled to said first temperature for energizing said heating means.

4. In an ice maker, an ice mold, means for filling said mold with water to be frozen, means for removing the frozen contents from said mold, a thermal motor adapted upon being heated from a first predetermined temperature to a second predetermined temperature to drive said removing means to elfect removal of the contents of said mold, means for refrigerating said mold and said thermal motor, means for heating said thermal motor, means responsive to said thermal motor being cooled to its said first temperature for energizing said heating means, and means responsive to said thermal motor being heated to its said second temperature for controlling said filling means.

5. In an ice maker, an ice mold, means for removing the frozen contents from said mold, a thermal motor including a member adapted to occupy one position when said motor is at a first predetermined temperature, and movable to a second position when said motor is heated to a second predetermined temperature higher than said first temperature, means for transmitting movement of said member to said removing means, means for refrigcrating said mold and said thermal motor whereby said mold and said motor are cooled .at analogous rates, means for heating said thermal motor, and means responsive to movement of said member to its first position for rendering said heating means operative.

6. In an ice maker, an ice mold, means for filling said ice mold with water to be frozen, refrigerating means for said mold, means for removing ice from said mold, heat motor means for driving said ice removing means, said heat motor means including a member adapted to occupy a first position when said heat motor means is at a first predetermined temperature, and to move to a second position when said motor means is heated to a second predetermined temperature higher than said first temperature, said heat motor means being subjected to the effect of said refrigerating means, whereby said ice mold and said heat motor means are cooled at analogous rates, means for heating sad heat motor to cause said member to move from its first position to its second position, means connecting said member to said ice removing means whereby movement of said member from its first to its second position causes ice to be removed from said mold, and means responsive to movement of said member from its second positon to its first position for rendering said heating means operative.

7. In an ice maker, an ice mold, means for removing the frozen contents from said mold, a container, an expansible-contractible material in said container adapted to undergo substantial volumetric change when subjected to a change in temperature between two predetermined values, a movable member associated with said container and actuated between two positions by the expansion and contraction of said material, means for transmitting movement of said member to said removing means, means for refrigerating said mold and said container whereby said mold and said container are cooled at analogous rates, means for heating said container, and means responsive to movement of said member for controlling said heating means.

8. A self controlling power unit for ice makers or the like comprising, a container, a substance in said container, said substance being adapted to undergo substantial volumetric change when subjected to a change in temperature between two predetermined values, a mov able member associated with said container and actuated by said substance when said substance undergoes volumetric change, whereby said member occupies one position when said substance is at the lower of its said two temperature values and another position when said substance is at the higher of its said temperature values, movement of said member being employed to actuate an ice making mechanism, means for heating said substance, and means responsive to said substance being cooled to the lower of its said two temperature values for rendering said heating means operative.

9. In an ice maker, an ice mold, means for removing the frozen contents from said mold, a thermal motor for driving said removing means, said thermal motor comprising a container, an expansible-contractible ma-' terial in said container adapted to undergo substantial volumetric change when subjected to a change in temperature between two predetermined values, a movable member associated with said container and actuated between two positions by the expansion and contraction of said material, means for transmitting movement of said member to said removing means, a heat storage mass in heat exchange relationship with said container for increasing the heat storage capacity of said thermal motor, means for refrigerating said mold and said motor, whereby said mold and said motor are cooled at analogous rates, means for heating said thermal motor, and means responsive to movement of said member said heating means.

10. In an ice maker adapted for use in a domestic refrigerator or the like having refrigerating means, an ice mold, means for removing the frozen contents from said mold, said removing means including a thermal motor and means for heating said thermal motor, said ice mold and said thermal motor both being adapted to be subjected to the effect of said refrigerating means, and means responsive to said thermal motor being refrigerated to a predetermined temperature for energizing said removing means.

11. In an ice maker adapted for use in a domestic refrigerator or the like having refrigerating means, an ice mold, a thermal motor for removing ice from said mold, means for heating said thermal motor to a first predetermined temperature, said thermal motor and said ice mold both being adapted to be subjected to the effect of said refrigerating means, and means responsive to said thermal motor being refrigerated to a second predetermined temperature lower than said first temperature for energizing said heating means.

12. In an ice maker adapted for use in a domestic refrigerator or the like having refrigerating means, an ice mold, means including a thermal motor and adapted upon heating of said motor to effect removal of ice from said mold, said ice mold and said thermal motor both being adapted to be subjected to the effect of said refrigerating means, means for heating said thermal motor, and switching means actuated by said thermal motor for controlling energization of said heating means.

13. In an ice maker adapted for use in a domestic for controlling ainwa e he: ike avi g.- e isere i mea an e; m k n m h ni mi clud ne an c m d. a thennal motor adapted uponbeing heated to actuate said meeha;v

ing mea ns actuated by; said thermal motor for controlling:

energization of said heating means.

14.. A self-controlling; power unit for ice, makens, or

the like .comprising, a container, a substance in said; container, said substance being adapted to undergo substantial volumetric change when, subjected to a change in temperature between two predetermined values, a movable member associatedv with said container and actuated by said substance when said substance. undergoes volumetric change, whereby saidmember occupies one posi-.

tionwhen saidsubstanceis' at the lower of its said two temperature values: and; another position when said substance issat the higher of its said temperature: values,v

movement oft-said member being employed to actuate an ice making mechanism, means for heating said substance,

and switching means actuated by said member for'ener gizing said heating means when said substance is cooled to said lower temperaturevalue and for deenergizi'ng said heating-means. when said substance isheated to said" higher temperature value.

References Cited in the file of this patent UNITED STATES PATENTS 2,161,321 Smith June-'6', 1939 2,212,424 Miner Aug. 20, 1940 2,435,802 Smith Feb; 10, 1948 2,717,498 Shagalofl Sept. 13, 1955: 2,808,707 Chace Oct. 8, 19 57 2,833,123 Kennedy May 6', 1958 2,863,298 Hellstrom Dec. 9, 1958' 2,869,060 Chace Jan. 13, 1959" 2,912,835 Modes Nov. 1-7, 1959

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