US3284610A

US3284610A - Heat operated refrigerator operable on gas or electricity

Info

Publication number: US3284610A
Application number: US417936A
Authority: US
Inventors: Grubb Gunnar Axel
Original assignee: Electrolux AB
Current assignee: Electrolux AB
Priority date: 1963-12-16
Filing date: 1964-12-14
Publication date: 1966-11-08
Anticipated expiration: 1983-11-08
Also published as: SE304023B

Description

N 1966 G A GRUBB 3,284,610

HEAT OPERATED REF RIGERATOR OPERABLE ON GAS OR ELECTRICITY Filed Dec. 14, 1964 2 Sheets-Sheet l INVENT ATTORNEY 2 Sheets-Sheet I A ATTORNEY G. A. GRUBB HEAT OPERATED REFRIGERATOR OPERABLE ON GAS OR ELECTRICITY Nov. 8, 1966 Filed Dec. 14, 1964 United States Patent 3 284 610 HEAT OPERATED REFRIGERATOR OPERABLE 0N GAS 0R ELECTRICITY Gunnar Axel Grubb, Bromma, Sweden, assignor to Aktiebolaget Electrolnx, Stockholm, Sweden, a corporation of Sweden Filed Dec. 14, 1964, Ser. No. 417,936

Claims priority, application Sweden, Dec. 16, 1963,

13,979/63 4 Claims. (Cl. 219279) My invention relates to heat operated refrigerators operable by gas or electricity.

It already has been proposed to control the operation of heat operated refrigerators of this kind by a control member movable between two operating positions, in one of which the refrigerator is adapted to be operated by gas and in the other by electricity.

In such a control, movement of the control member between its two operating positions is essentially unrestrained, and the control member may be freely moved to the position which renders the refrigerator operable by the desired source of heat. This is objectionable when one of the sources of heat is not available for operation of the refrigerator, as, for example, when the refrigerator is installed in a travel trailer located in an area where electricity is not available, because the control member inadvertently or accidentally may be moved from the position which renders the refrigerator operable to the other position associated with the source of heat that is not available. Under such conditions, the refrigerator will not function to preserve food. Further, it is desirable to employ a control which is operable to disconnect the refrigerator not only from one or the other of the sources of heat but also from both sources at the same time to make certain the refrigerator will not start operating if not desired if the control member inadvertently is left in an operating position.

It is an object of my invention to provide for a heat operated refrigerator a control having a control member movable in a range from either one of two operating positions to the other of the two operating positions to adapt the refrigerator for operation by gas or by electricity, the control functioning to interrupt and halt movement of the control member during its back and forth movement in the range at a position which is intermediate the two operating positions and effective to disconnect the refrigerator from both sources of heat at the same time.

The invention, together with the above and other objects and advantages thereof, will be more fully understood upon reference to the following description and the accompanying drawing forming a part of this specification, and in which:

FIG. 1 illustrates more or less diagrammatically heat operated refrigeration apparatus embodying the invention;

FIG. 2 is a fragmentary sectional view taken at line 22 of FIG. 1;

FIG. 3 is an elevational view taken at line 33 of FIG. 1 to show parts more clearly; and

FIG. 4 is a sectional view like one taken at line 44 of FIG. 3 illustrating a modification of the invention.

In FIG. 1 of the drawing, the invention is shown in connection with heat operated absorption refrigeration apparatus containing an inert pressure equalizing gas. Refrigerant vapor is expelled from absorption liquid in a vapor lift pipe of a vapor-expulsion unit 11 and passes through the upper part of a standpipe 12 and a conduit 14 to a condenser. The refrigerant vapor, such as ammonia, is liquefied in the condenser and flows into an evaporator in which the refrigerant evaporates and diffuses into an inert gas, such as hydrogen, to produce a refrigerating effect within the thermally insulated interior of a refrigerator cabinet. The resulting gas mixture of refrigerant and inert gas flows from the evaporator to an absorber including a coil 15 and an absorber vessel 16 to which the lower end of the coil is connected, such gas mixture entering the absorber vessel 16 through a conduit 17.

In the absorber refrigerant is absorbed from the gas mixture into absorption liquid, such as water, which is delivered thereto through a conduit 18, and the absorption liquid enriched in refrigerant passes into the absorber vessel 16. The inert gas is returned from the absorber to the evaporator in the path of flow including a conduit 19, and the enriched absorption liquid is conducted through a conduit 20 and inner pipe 21 of a liquid heat exchanger 22 to the vapor-expulsion unit 11.

The raised absorption liquid from which refrigerant vapor has been expelled flows by gravity from standpipe 12 through the outer pipe 23 of liquid heat exchanger 22 and conduit 18 into the upper part of absorber coil 15. In order to simplify the drawing, the condenser, evaporator and connections therefor have not been shown, such parts being well known and their illustration not being necessary for an understanding of this invention.

Absorption solution enriched in refrigerant flows from the absorber vessel 16 through conduit 20 and inner pipe 21 of liquid heat exchanger 22 into the lower end of vapor lift pipe 10 which is in thermal exchange relation with a heating tube 24 at 25. The heating tube 24 is arranged to be heated by an electrical heating element 26 disposed within the tube. Vapor generated in the vapor lift pipe 10 by heating effected by the heating tube 24 raises liquid therein by vapor lift action and fiows from the upper end thereof through the upper part of standpipe 12 into conduit 14 and passes to the condenser, as previously explained.

The vapor-expulsion unit 11 in its entirety, together with a major portion of the liquid heat exchanger 22, are embedded in a body of insulation 27 retained in a metal shell or casing 28 having an opening 29 at the bottom thereof. The heating tube 24 is embedded in a part of the insulation 27 which is intermediate the ends thereof and spaced from the top and bottom ends of the shell 28.

Electrical conductors

30 and 31 for the electrical heating element 26 pass through the bottom opening 29 of the shell 28 and extend through the insulation 27. The heating tube 24 snugly receives the heating element 26 which may comprise a cartridge housing an electrical wire or the like having a relatively high resistance that generates heat when connected to a source of electrical energy. It is usually the practice to provide a passage in the body of insulation 27 which extends to the exterior of the insulating body, so that the electrical heating element 26 may be readily inserted into and removed from the heating tube 24.

As shown in FIG. 1, the vapor-expulsion unit 11 is arranged to be operated at will by two independent sources of heat, each of which alone is capable of supplying heat at an adequate rate and at a sufficiently elevated temperature to the vapor lift pipe to effect normal operation of the refrigeration apparatus under all conditions under which the apparatus is intended to be operated. This is accomplished by providing a second heating flue 32 which is in thermal exchange relation with the vapor lift pipe 10 at 33. A fluid fuel burner 34 is arranged to be supported in an upright position within the bottom part 32a of the heating flue, so that the combustion gases will be used most effectively for heating the heating flue 32. The burner 34 is connected to a source of supply of gaseous fuel by sections 35a and 35b of a pipe 35 in which is connected a valve 36.

As shown in FIG. 2, the valve 36 for controlling the supply of gaseous fuel to the burner 34 includes a casing 37 of cylindrical shape which is fixed to a suitable support (not shown). Within the casing is positioned a rotatable valve member 38 fixed to a shaft 39. The valve member 38 is formed with a passage 40 which connects the pipe 35 and burner 34 when the valve member is in the position illustrated in FIG. 2.

' The electrical heating element 26 is connected by

conductors

30 and 31 to a source S of electrical energy in an electrical circuit which also includes

conductors

41 and 42 and an electric switch 43. The switch 43 comprises a member 43a of cylindrical shape which is formed of electrically conductive material and fixed to the shaft 39 and insulated therefrom in any suitable manner.

Brushes

44 and 45, to which the

conductors

41 and 42 are connected, are adapted to bear against the periphery of the switch member 43a. The periphery of the switch member 43a is provided with an insulating section 46 over which the

brushes

44 and 45 move when shaft 39 is rotated.

When refrigeration apparatus like that illustrated in FIG. 1 is intended to be operated electrically, the electrical heating element 26 is connected to the source S of electrical energyf When the refrigeration apparatus of FlGpl is intended to be operated by gaseous fuel, the burner 35 is connected to the source of supply of the fuel and ignited. Accordingly, the relationship of the valve member 38 and the insulating section 46 of the switch 43 is such that in a first position of the shaft 39 the valve 36 is open and the

brushes

44 and 45 engage the insulating section 46 of the switch 43, and in a second position of the shaft 39 the valve 36 is closed and the

brushes

44 and 45 are removed from the insulating section 46 of the switch 43. The shaft 39 can be turned either to one of two positions, namely, a first valve open position, or a second switch closed position which will render the electrical heating element 26 operable to effect heating of the refrigeration apparatus. In accordance with my invention, the outer end of the shaft 39 is formed with an outer tubular section 39a and journaled in a circular plate or disk 47 supported in any suitable manner (not shown). To the shaft 39 in a plane perpendicular to its axis is fixed one end of an elongated control member 48. The control member 48 includes inner and outer elements 48a and 48b which are in alignment and axially separated from one another, as indicated at 49. Alternatively, one of the elements 48a and 48b may be formed with a hollow tubular seeone axially movable within the other. The inner end of the inner element 48a passes through openings 50 in the hollow tubular section 39a of the shaft 39 and is held therein by a cross bar 51 fixed to the element 48a.

A helical spring 52, which extends axially of the adjacent ends of the elements 48a and 48b and bridges the gap 49 therebetween, is fixed at its ends at 53 and 54 to the elements 48a and 48b. The outer end of the control member 48 is provided with a hand grip 55 which extends axially of the shaft 39. The control member 48, the extreme outer end of which may be pointed, as indicated at 480, is movable in front of a plate 56 having suitable indicia EL and O and GAS, the indicia EL and GAS representing the positions to which the control member 48 is moved to render the refrigerator operable by electricity and gas, respectively, and the indicium representing the off position to which the control member 48 is moved to disconnect the refrigerator from gas and electricity when one or both of these sources of heat are available.

As seen in FIG. 3, the circular plate or disk 47 is formed with a peripheral surface 57 of arcuate form extending between two radially extending walls or

abutments

58 and 59 which function as stops at the EL and GAS positions of the control member 48. Adjacent to the

stops

58 and 59 the peripheral surface 57 is recessed to form grooves or

valleys

60 and 61 which tion so that they may be telescopically connected with gently slope radially outward toward zones 62 and 63 of the peripheral surface 57 which are of arcuate shape. Directly opposite the indicium O of the plate 56 the peripheral surface 57 is formed with a valley or depression 64 disposed between the adjacent ends of the zones 62 and 63. It will be observed that the parts of the peripheral surface 57 of the plate 47 having the greatest radius are those regions of zones 62 and 63 adjacent to the depression or valley 64, and that the radial distance from the shaft 39 to the bottom of the valley or depression 64 is substantially greater than the radial distance from the shaft 39 to the bottoms of the

valleys

60 and 61.

To the outer element 48b of the control member 48 is fixed a resilient member 65 which is of semi-circular form and spring-like in character. When movement is imparted to the shaft 39 by moving the control member 48, the resilient member 65 freely rides over the peripheral surface 57. When the resilient member 65 moves radially outward from the

valleys

60 and 61 to the zones 62 and 63, the control elements 48a and 48b are axially separated against the tension of the helical spring 52. Hence, the helical spring 52 functions to resiliently bias the resilient member 65 against the peripheral surface 57, such biasing action being least when the resilient member 65 is in the

valleys

60 and 61 and greatest when the member 65 is at the regions of the zones 62 and 63 immediately adjacent to the valley 64.

It will be seen that the

radially extending walls

58 and 59 are apart which determines the angular movement of the control member 48 from the position EL in which electric operation can be effected and the position GAS in which gas operation of the refrigerator can be effected. In these two operating positions of the control member 48 the resilient member 65 of semi-circular form snugly seats in the

valleys

60 and 61. When the control member 48 is moved from the EL position to the GAS position or vice versa, it must move through the 0 position in which the valve 36 is closed and the electric switch 43 is open. Hence, in the 0 position of the control member 48 the refrigerator cannot be operated either by gas or electricity. Further, when the control member 48 is moved in either direction toward the 0 position, the biasing action of the spring 52 progressively increases to an optimum value at the opposing side walls of the valley 64. When the resilient member 65 subsequently moves into the valley 64 the biasing action of the helical spring 52 is still at a value closely approaching the optimum value and movement of the control member 48 at the 0 position is interrupted and halted in the same manner that movement of a vehicle is interrupted and halted when its wheels fall into a deep ditch. It is then necessary to apply force on the control member 48 in such manner that the movement of the resilient member 65 out of the valley 64 at the 0 position will be promoted.

It will now be understand that accidental or inad vertent movement of the control member 48 from one operating 'position to the other operating position is prevented by my improved control which I have described above and illustrated, and that the control embodies the feature of halting and interrupting movement of the control member in its path of movement at a position in which neither gas or electricity can be supplied to the heat operated refrigerator.

The circular plate 47 comprises structure defining a curved path of convex form having an elongated surface 57 which extends between first and

second regions

60 and 61 of the surface and in which all parts thereof including the first and

second regions

60 and 61 are in a single plane perpendicular 'to the surface, as best shown in FIG. 1. The inner end of the arm 48 is anchored at 39a to the rotatable shaft 39 for angular movement about the axis of the shaft. The element 65 is fixed to the outer end of the arm 48.

It will now be understood that the shaft 39 and arm 48 function as mounting means for the element 65 to effect movement thereof on the surface 57 between the

regions

60 and 61 by force imparted to the arm 48. The arm 48 includes an outer part 48b which is movable in the direction of its length with respect to an inner arm part 48a. The parts 48a and 48b of the arm 48 and the spring 52 therebetween function as means for holding the element 65 against the surface 57 by force acting on the element 65 through the outer arm part 48b. The spring 52, which is under tension functions to bias the outer arm part 48b toward the inner arm part 48a.

The surface 57 at each of the

regions

60 and 61 has a recess including a bottom and opposing sides. The sides of the recesses at 60 and 61, which are nearer to the ditch 64, are inclined toward the latter and the sides thereof, which are removed from the ditch 64, serve as

abutments

58 and 59 which are in the path of movement of the element 65 when the latter is seated in the recesses at the

regions

60 and 61, respectively.

The element 65, after being moved from either of the first and

second regions

60 and 61 toward the ditch 64, is movable on a part of the surface 57 at either side of the ditch and adjacent thereto and along either one of the sides of the ditch 64 to the bottom thereof respon sive to a first force imparted thereto which is of one magnitude. Each side of the ditch 64 is inclined at such an angle to the part of the elongated surface 57 which is adjacent thereto and extends therefrom that the element 65 is movable along the surface 57 toward either one of the first and

second regions

60 and 61 from the bottom of the ditch 64 along either one of the sides thereof responsive tov a second force imparted thereto at the bottom of the ditch which is of higher magnitude than the first force.

In addition, a separate lock device can be provided which automatically functions to lock the control member 48 when it reaches its or off position. As shown in FIG. 4, such a lock device 66 may be provided at the inner element 48a of the control member 48. The lock device 66 comprises a plunger 67 which is axially movable within a hollow sleeve 68 fixed to the inner element 48a. A coil spring 69 is disposed within the sleeve 68 and retained therein between the plunger 67 and a flange 70 on the sleev The plunger 67 is urged toward the plate 47 by the spring 69. When the control member 47 extends vertically upward and at the position, the plunger 67 moves into an opening 71 in the plate 47 and locks the control member 48 in the O or off position. A flexible chain or pull cord 72 having one end fixed to the plunger 67 and its opposite end extending outside the sleeve 68 at the flange 70 may be pulled to withdraw the plunger 67 from the opening 71 in the plate 47 and permit the control member 48 to be moved from the 0 position to either operating position at the

valleys

60 and 61 in the peripheral surface 57.

While I have shown and described particular embodiments of the invention, it Will be apparent that modifications may be made without departing from the spirit and scope thereof, as set forth in the claims.

I claim:

1. In apparatus of the class described having a refrigerating system of the type alternatively employing gas or electricity as power sources and in which cooling is effected by a heat operated refrigeration unit provided with a heat receiving part, the part being heated by a gas burner heating means disposed adjacent thereto and means for supplying gas energy to the burner heating means and also being heated by electrical heating means and means for conducting electrical energy to the electrical heating means, the combination of control means connected to the gas energy supply means and to the electrical energy conducting means which is operable to connect one or the other of the energy means respectively to its associated heating means, said control means comprising structure defining a curved path of convex form having an elongated surface which extends between spaced first and second regions and in which all parts of the surface including the first and second regions thereof are in a single plane perpendicular to the surface, an element means for mounting the element for movement on the elongated surface between the first and second regions, means for holding the element against the surface by force acting thereon in a direction perpendicular to the surface, the control means being operable to connect only one of the energy means to its associated heating means responsive to movement of the element to the first region on the elongated surface and being operable to connect only the other of the energy means to its associated heating means responsive to movement of the element to the second region on the elongated surface, the holding means being operable to hold the element against the elongated surface at the first and second regions and at all regions of the surface between the first and second regions thereof, the surface between the first and second regions having a depression or ditch of concave form including a bottom and opposing sides, each of the sides being inclined toward a different one of the first and second regions, the element, after being moved from either of the first and second regions toward the ditch, being movable on a part of the surface at either side of the ditch and adjacent thereto and along either one of the inclined sides of the ditch to the bottom thereof responsive to a first force imparted thereto which is of one magnitude, and each side of the ditch being inclined at such an angle to the part of the elongated surface which is adjacent thereto and extends therefrom that the element is movable along the surface toward either one of the first and second regions from the bottom of the ditch along either one of the sides thereof responsive to a second force imparted thereto at the bottom of the ditch which is of higher magnitude than the first force.

2. The combination set forth in claim 1 in which the mounting means for the element includes an arm having inner and outer ends, a rotatable member having an axis, means for anchoring the inner end of the arm to the rotatable member for angular movement about the axis, and means for fixing the element to the outer end of the arm.

3. The combination set forth in claim 2 in which the arm includes inner and outer parts, the outer part being movable in the direction of its length with respect to the inner part, and the means for holding the element against the surface including the inner and outer parts of the arm and resilient means therebetween which is under tension and functions to bias the outer arm part toward the inner arm part.

4. The combination set forth in claim 1 in which the surface at each of the first and second regions has a recess including a bottom and opposing sides, each of the sides of the recesses nearer to the ditch being inclined toward the latter and each of the sides of the recesses remote from the ditch being in the path of movement of the element and functioning to stop movement of the element when the element is seated in the recess at which movement of the element is stopped.

References Cited by the Examiner UNITED STATES PATENTS 1,069,518 8/1913 Barnett 200-15 2,304,302 12/1942 Crupi 219-279 3,080,729 3/1963 Grubb 62497 3,093,978 6/1963 Grubb 62236 3,105,363 10/1963 Van Der Scher 62148 RICHARD M. WOOD, Primary Examiner. ROBERT A. OLEARY, Examiner. C. L. ALBRITTON, Assistant Examiner.