Control for gas-electric refrigerator
[451 Apr. 1, 1975 United States Patent [:91  
 Sellerstam 3.093.478 6/]963 62/236 3.284.610 ll/l966 Grubbmmnm.,..........l..t.....2l9/279 l l CONTROL FOR GAS-ELECTRIC REFRIGERATOR [75] Inventor: Kjell Birger Sellerstam. Bandhagen.  
 Sweden Prinmry Examiner-C. L. Albritton I73] Assignee: Aktie bolaget Electrolux, Stockholm.  
 Sweden ABSTRACT [22] Filed: Oct. 1, 1973 A manual control for a refrigerator which can be operuted by either gas or electricity. The control unit can be either two-way or three-way. In the latter means are provided for switching to any of the following modes: gas; llO volt AC; and [2 volt DC. The switching mechanism is selectively operative for the desired mode of refrigerator operation.  
  607 3m v 1 21 8 6. v l  
  9 nme .2 1M mmmv &#34;7 &#34;2 HH I: 3 mmm 5 U I. U 2 mmh 0 mm 4 &#34;&#34;2 N NE 0 N I C0 m. M D. S A UhF H an 2 555 [56] References Cited UNITED STATES PATENTS 13 Claims, 10 Drawing Figures House trailers or other mobile living accomodations require a refrigerating system which preferably can be operated alternatively from different power sources. When the trailer is mobile. the refrigerator can be operated by a gas supply or a l] volt DL. battery. Ho\ve\ er. when the trailer is parked in a location where a source of alternating current is available. the refrigerator may be connected to the convenient A.(. source.  
  It is particularly desirable to provide a single manual control for selectively activating and tie-activating the various power sources which overcomes the drawbacks of known multiple control arrangements for operating and disconnecting various power supplies.  
  It is an object of the present invention to pro\ide a two or three-way control unit for selecting \arious power supply modes fora portable relrigerator. such as gas; I It) volt A.(.. or l2 volt D1. electricity.  
  Another object of the present invention is to provide a rotatable operating cam body which is also capable of axial movement. and that is selectively coupled to a gas valve handle or to an electric switch lever.  
  A further object ofthe present invention is to provide an interlock arrangement between the gas valve and the electric switches to prevent the application of power from a source other than the selected power source.  
  Another object of the present invention is to provide a control device for a refrigerator in a mobile home or trailer which has a single knob and operates simply and efliciently.  
  The invention will now he more fully described with reference to the accompanying drawings in which:  
  FIG. I is a diagrammatic vertical section ofa heat operated lnobile refrigerator having a manual control device for gas-electric operation constructed according to the teachings of the present invention:  
  FIG. 2 illustrates more or less diagr:unmatieally the heat operated refrigeration apparatus suitable for use in the refrigerator shown in Flti. l.  
  FIG. 2a is a sectional view taken along the lines 2u2u of FIG. 2., showing certain details of construction with respect to the electrical heating elements of the invention:  
  FIG. 3 is a side elevation view. partly in crosssection, of the control device with the operating shaft in the off position and the gas valve being closed;  
  FIG. 4 is a side elevation view. partly in section. of the control device with the operating shaft in the gas position and the gas valve rotated to an open position.  
  FIG. 5 is a side elevation view. partly in section, of the control device in the off position similar to what is shown in FIG. 3. but with the operating shaft and associated cam body pushed inwardly:  
  FIG. 6 is a side elevation view. partly in section. of the control device with the operating shaft rotated to the DC. battery position;  
  FIG. 7 is a side elevational view. partly in section. of the control device with the operating shaft further rotated to the A.(. position:  
  FIG. 8 is a front elevational view of the cam body of the control device suitable for three-way operation; and  
  FIG. 9 is a front elevational view of another embodiment of the invention illustrating a two-way cam body of the control device.  
 DIESCRIPl&#39;ION ()F &#39;l&#39;HF. PRlii-liRRl-il) liMliODllvlliN&#39;f Referring to FIG. I. the invention is shown diagrammatically as installed in a mobile refrigerator of the type used in house trailers or mobile homes. The refrigerator referred to generally by the numeral It) is constituted of a cabinet [2 having thermally insulated walls 14 defining a refrigerated storage compartment 16. In  
 l the latter is arranged a cooling element or evaporator [8 of a suitable heat operated refrigeration apparatus. Access to the storage compartment l6 may be gained by means of a door at the front of the cabinet II. The heat operated refrigeration apparatus is preferably t5 but not limited to the well known uniform pressure alm (iii sorption type. In a refrigerator of this typc the cooling element [8 is connected to other parts of the apparatus including a generator 22 which is mounted in a space 24 at the rear of the cabinet 12.  
  In heat operated refrigerators of the present type. and as seen in FIGS. 2 and 2a. a refrigerant vapor is expelled from absorption liquid in a vapor lift pipe 26 of the generator 22. The refrigerant vapor thus expelled passes through a conduit 28 to a condenser 30. The re- 35 frigerant vapor is then liquefied in the condenser 30 and flows into evaporator unit 18. In the evaporator. the refrigerant diffuses into an inert gas to thereby produce a refrigeration effect. The resultant gas mixture of refrigerant and inert gas flows from the evaporator I8 to an absorber 34 which may be of the air-cooled type 35 sorption liquid. which is conducted into the absorber 34 by means of a conduit 42. The absorption liquid enriched in refrigerant then passes into the absorber vessel 36. &#39;l&#39;hereafter. the inert gas is returned from the absorber 34 to the evaporator [8 by means of a conduit 44 and heat exchanger 38&#39;. and the enriched absorption liquid is conducted through a conduit 46 and inner pipe 48 of heat exchanger 50 to the generator 22.  
  The absorption liquid. elevated in vapor lift pipe 26 and from which refrigerant vapor has been expelled. flows by gravity from a stand pipe 52 through the outer pipe 54 of liquid heat exchanger 50 and conduit 42 into the upper part of absorber coil 34.  
  The vent conduit 56 connects the lower end of the condenser 30 to the heat exchanger 30 through which the gas mixture flows from the evaporator. Thus. the absorption solution. enriched in refrigerant. flows from the absorber vessel 36 through the liquid heat exchanger 50 into the lower end of the vapor lift pipe 26 which is in thermal exchange relationship at location 58 with a heating tube (all.  
  As seen in FIG. 2. the heating tube 60 is embedded in insulation and is heated by either an A.C. heating element 62 having electrical leads 621: or alternatively by a DC. heating element 64 provided with electrical leads 641:. both of which are mounted within the heating tube. A heating flue (15 is shown in heat exchange relationship with the vapor lift pipe 26. A fluid fuel burner 63 is arranged in the bottom part of the flue 65 M and is coupled to gaseous source through pipe 67 conti\el supply heat at a proper rate and at sufficiently ele\ated temperature to the vapor lift pipe 26.  
  The heating of the tube 60 causes the vapor generated in the contiguous vapor lift pipe 26 to raise the llL|- uid tltet&#39;ein by vapor lift action. so that the vapor flows from the upper end of pipe 26 through the upper part of the standpipe 52 into the conduit 28 and then into the condenser 30. as explained ltereinabove.  
  Referring to FIGS. 3-9. the refrigerator control device which embodies my invention is operatively connected to a multiple position electric toggle switch 66 as well as gas valve handle 68 of the gas \alvc 70. The control device is provided with a Dshapcd control shaft 72 having a knob 74 mounted in the cabinet I2 under the refrigerator storage compartment I6. The knob 74 has indicia thereon for the angular positions of the control shaft 72. such as OI-I&#39; ELFC&#39;I&#39;RICI liA&#39;l &#39;l&#39;l-iRY. and &#34;GAS. A U-shaped bracket 76 is secured to the rear of the cabinet I2 and is provided with a plate 78 removably held thereto. The bracket 76 and plate 78 are provided with aligned holes 80 and 82. respectively.  
  A control body referred to generally by the number 84 is shown in front elevation in FIG. 8 as well as in various operative positions illustrated in FIGS. 3-7. The control body 84 has a neck portion 86 provided with a ring 88. A compression spring 90 is positioned at one end against the plate 78. and surrounding the ring 88. and the control shaft 72 is provided with a flange 92 against which the other end of the spring 90 is located. The spring maintains the control body 84 in the normal situs of the control body.  
  Mounted on the side 94 of the U-shaped bracket 76 is the gas valve 70 as well as the electric switching device 95.  
  The gas valve 70 is shown in FIG. 3 in closed position. with the handle 68 directed downwardly. The control body 84 has a rearwardly extending L-shaped lip 96 provided with a slot 98 formed between the upstanding portion ofthe lip 96 and a side wall I00. As seen in FIG. 3. the end 681: of the handle 68 is positioned in the upstanding slot 98 in the normal rest position of the control body. In this position. the gas valve 70 is in the closed position. If it is desired to open the gas valve 70. the knob 74 is rotated counter-clockwise to the gas position in which the control shaft 72 and the control body 84 are all rotated in a counter-clockwise direction which. at the same time. rotates the gas valve handle 68 to a substantially horizontal position inasmuch as the end 6811 is captured in the slot 98 of the lip 96. as seen in FIG. 4. Thus. the gas valve 70 is opened only when the handle is rotated in a counterclockwise direction. It will be noted that when the gas valve handle is turned in a counter-clockwise direction the knob 74 cannot be pushed inwardly. since the end of the toggle switch 66 projects in channel I00 of the control body 84 (FIGS. 4 and 8) and substantially no axial movement of the control body 84 is permitted. The restricted movement of the control body results since the plate 78 is provided with a headed pin I02 projecting outwardly therefrom and accommodated in a through slot I04 having an enlarged end I041: in the control body 84. Thus. the shank I021! of the headed pin I02 travels in the slot I04 during the movement of the gas valve handle 68 toward the open position of the gas valve 70 and axial movement of the control body 84 is prevented. However. when the gas valve handle (ill  68 is turned to the vertical position shown in FIG. 3. the headed pin I02 is in the enlarged end 104a of the slot I04. and the toggle switch 66 is at the position A in the contiguous channel I06 in the control body 84. In this position. the control body can be mo\ ed axially and pushed inwardly so that the slot 98 mo\es away from the end 68:! of the gas valve handle 68. as seen in FIG. 5. and the deep channel I06 can accommodate the switch 66 upon axial movement of the control body 84. Simultaneously. the enlarged end I04 of the slot I04 is removed from the headed pin I02 and the knob 74 for the control body 84 is free to move in a clockwise direction to assume positions of the control body as seen in FIGS. 6 and 7. The position B of FIG. 8 is particularly shown in FIG. 6 in which the toggle switch 66 is illustrated in a down condition whereby the llvolt DC. electrical power supply is connected to the control device. When the knob 74 is rotated further clockwise to the position C of FIG. 8. the switch 66 is turned to the off position and when the knob 74 is continued to be rotated in a clockwise direction. the switch 66 is moved to its upward condition D of FIG. 8 and particularly shown in FIG. 7. In this position. a l Ill-volt AC. power source is supplied to the control device.  
  It should be noted. as seen in FIGS. 6 and 7. that during the movement of the control body 84 from positions B. C. and D. the headed pin I02 engages the rear surface of the control body 84 and slides thercalong.  
  FIG. 9 shows another embodiment of the control body referred to generally by the numeral I08 in which identical parts of the control body 84 shown in FIG. 8 bear the same reference numerals therein. The body I08 has a channel I10 and a contiguous channel I [2. The latter channel has a different configuration from the channel I06 of the control body 84 shown in FIG. 8, so that the toggle switch 66 can move from an off position E to a downward on position F in which the I I0- volt A.C. power source is supplied to the control device. This arrangcment provided for only a two-way control device but has the same interlock feature of the previously described control device.  
  The present control device for a refrigerator of the mobile type features a single control member in which there is an interlock between the gas valve and the electric switch for both lZ-volt DI. and l Ill-volt AL. operation. The control device is selectively and independently coupled to either the gas valve handle or the electric toggle switch.  
 What is claimed is:  
  I. In a combination with a refrigerating system of the type alternatively employing gas or electricity as power sources in which cooling is effected by means of a refrigeration unit having a heat receiving part provided with a gas heat supply means and a heating element. an AC. electric heat supply means and a D.C. electric heat supply means. each having a separate heating element. at single control mechanism for selectively and independently switching to a selected one of said heat supply means while the other heat supply means are disconnected. said control mechanism being movable in one direction to connect the gas heat supply means to its respective heating element. and to disconnect the electric heat supply means. and said control mechanism being movable in the reverse of said one direction to selectively connect at least one of the DC. and AC. electric heat supply means to its respective heating elemcnt while said gas heat supply means remains disconnected.  
  2. The combination claimed in claim I wherein said gas heat supply means is provided with a valve and a valve operator. said control mechanism including a rotatable control body adapted to selectively engage and move said gas valve operator only when the control mechanism is rotated in one direction.  
  3. The combination claimed in claim 2 wherein said control body is provided with at least one shaped ehan nel. said electric heat supply means being provided with a switch and a switch actuator. the control body in one predetermined position thereof being adapted to be moved axially whereby said switch actuator enters said shaped channel and upon the further rotational movement of said control body said switch actuator is moved to selectively connect at least one of the DC. electric heat supply means and the A.(. electric heat supply means to its respective heating element.  
  4. The combination as claimed in claim 2 wherein said control body is provided with an outward extending lip having a slot. said valve operator being positioned in said slot and moved by said control body when the control mechanism is rotated to a position connecting said gas heat supply means to its respective heating element.  
  5. The combination as claimed in claim I wherein said control mechanism is provided with a control body having a thorough slot. said slot being provided with an enlarged end. a fixed headed stud projecting through said enlarged end of the slot in one position ofthe control body whereby said control body can move axially forward so that the head of the stud is situated in a plane behind said slot and the control body may be rotated to selectively connect one of the electric heat supply means to its respective heating element while the head of the stud remains behind the rear surface of the control body.  
  6. The combination as claimed in claim 5 wherein when the control body is rotated in a direction to connect said gas heat supply means to its respective heating element the shank of said headed stud is in the slot and the head is in a plane in front of said slot thereby preventing the forward axial movement of said control bodyv 7. The combination as claimed in claim 3 wherein said shaped channel is substantially arcuate. and said switch actuator is a toggle element that rides in said channel and is moved to various positions as the control body is rotated.  
  8. The combination as claimed in claim I wherein said D.C. electric heat supply means is a l2-volt system.  
  9. The combination as claimed in claim I wherein said control mechanism includes a control body, the latter being provided with a shaped channel. said electric heat supply means having a switch and a switch acfit] tuator. said switch actuator being in said shaped channel when said control body is rotated in the direction to connect said electric heat supply means to its respective heat element to thereby operate said s\\ itch actuator which in turn operates said switch,  
  I0. The combination as claimed in claim 2 wherein said control body has a projecting part that engages and moves said \alve operator when the control mechanism is rotated in one direction to connect the gas heat supply means to its heating element; but does not engage or move said valve o erator when the control mechanism is rotated in the opposite direction to connect a selected electric heat supply means to its respeeth e heating element.  
  II. The combination as claimed in claim 3 wherein said control body is rotatable and is provided with a control shaft. a spring surrounding said shaft at the end adjacent to the control body whereby said shaft is capable of rotatable movement and limited axial movement. and said control body being rotatable with said switch actuator in said shaped channel only after said control shaft has been first moved axially and then rotated in a predetermined direction 12. In a combination with a refrigerating system of the type alternatively employing gas or electricity as power sources in which cooling is effected by means of a refrigeration unit having a heat receiving part pro vided with a gas heat supply means and with heating elements connected to two electric heat supply means for heat from different kinds of electric energy sources. a single control mechanism for selectively and independently switching to a selected one of said heat supply means. and said control mechanism being movable in said one direction and further in the same direction to selectively connect at least one of the electric heat supply means to its respective heating element. while said gas heat supply means remains disconnected.  
  13. In a combination with a refrigerating system of the type alternatively employing gas or electricity as power sources in which cooling is effected by means of a refrigeration unit having a heat receiving part provided with a gas heat supply means and with two electric heat supply means for heat supply from different kinds ofelcctric energy sources. a single control mechanism for selectively and independently switching to a selected one of said heat supply means while the other heat supply means are disconnected, said control mechanism being movable in one direction from an off position to connect the gas heat supply means and to disconnect the electric heat supply means. and said control means being movable from the off position in the opposite of said one direction only after having been pushed axially to selectively connect at least one ofthe electric heat supply means to its respective heating element white said gas heat supply means remains disconnected.  
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