US2390993A - Temperature control for refrigerator cars - Google Patents

Description

L A n S R E a E D c TEMPERATURE CONTROL FOR REFRIGERATOR CARS Filed NOV. 8, 1941 INVENTORS M vflwlm. ATTORNEY5 I Patented Dec. 1 8, 1945 TEMPERATURE CONTR ATOR L FOR REFRIGER- CARS -' Clarence A. de Giers, Forest Hills, and Arthur Wickesser, St. Albans, N. Y., assignors to The Liquldometer Corporation, Long Island N. Y., a corporation of Delaware City,

Application November 8, 1941, Serial No. 418,366

3 Claims This invention pertains to apparatus for the control of temperature in a space. The invention has a great variety of uses, but since it was developed for control of temperature in refrigerator cars in transit the invention is, for convenience,

described in that connection, but it is not limited the car and readily accessible from outside the car whendesired.

Another object is to disclose an apparatus in which each of its operations is positive in action even under the severe service to which a refrigerator car is subjected.

This invention is an improvement on the invention disclosed in copending application Serial No. 418,365 filed November 8, 1941, by the present inventors and entitled Remote regulation of atmospheric condition. Said application has matured into Patent No. 2,371,428, dated March 13, 1945.

Further and other objects and advantages will be apparent from the specification and claims, and from the accompanying drawing which illustrates what is now considered to be a preferred embodiment of the invention.

The drawing shows the invention largely in diagrammatic form, unessential details being omitted.

Bulb It is located in the car and is connected by open-end tube l2 to bellows It, the bulb and their inner ends being pivotally connected by studs 28 and 30 to opposite ends of a floating link 32. An arm 38, fulcrumedat 36 on plate 22 is pivotall connected by pin 38 to the center of link 32. Mounted on the upper end of arm 34 is a cam roller 80.

As disclosed in deGiers Patent No. 1,943,267,

issued January 9, 1934, this arrangement of 0H- set similar bellows, liquid-filled and connected by a floating link, is effective to prevent movement of arm 34 due to changes of temperature of the bellows or tubes connecting them to bulb 20. However, when a change of temperature occursin the car and therefore in bulb in, liquid I5 therein will expand or contract and some of the liquid will be forced into or out of tube l2, causing bellows M to expand or contract axially, thereby swinging lever 34 about its fulcrum 36 through the instrumentality of link 32, the lower vend of which is stationary at an adjusted position. Briefly, the position of lever 34 is dependent on the position of pin ,38 -(in link 32), and the position of pin 38 is dependent upon the action of bellows H, at one end of tlre link, in combination with the manual adjustment at the other end thereof.

In the device of the above mentioned deGiers patent, any change of bulb temperature is simply indicated by a pointer, but in the present invention means are provided for adjusting the temperature to a predetermined value, the desired temperature being indicated by a manually adjustable lever 42 in cooperation with a graduated dial in the form of a disk 44 on the outside of case 2|.

Lever 42 is attached by pin 46 to the outer head of a spindle 48 in axial alignment with bellows 20 and rotatable by lever 42. The inner end of the spindle is threaded at 50 into the head 52 of bellows 20. When the spindle is rotated, collars 54 and 5B prevent lengthwise movement of the spindle, thereby causing threads 50 to move bellows head 52 axially, thus either lengthening or shortening bellows 20. Since bellows 20 is filled with incompressible liquid, and is fixedly mounted to the case by bracket 26, the movement of head 52, acting through stud 80, adjusts the position of the lower end of link 32, and, through pin 38, affects the movement of lever 34 about its fulcrum 3B. Spindle 48 is enclosed in a bellows as sealed at one endto head 52 and at its other end to the wall of case 2 I.

Lever 42 is held in its adjusted position by a boss 58 on the lever engaging an appropriate socket in disk 44. A spring 62 holds boss 58 in the selected socket until manual depression I of the other end of the lever frees the boss to permit movement to another selected position;

When heat is needed in the car it is supplied by a gas heater, which warms a heat-exchanger 66 from which fluid circulates through suitable radiators in the car. The fluid is usually a solution of ethylene glycol and water. The fuel gas is usually propane, furnished in liquefied form in drums which are held in racks underneath the car. Thedrums are equipped with a regulator valve through which gas at suitable pressure I 2,390,993 UNITED STATES PATENT OFFICE Casing 2| contains a valve 80 from which a pipe 82 leads to chamber 84 above diaphragm l4. Adjacent heater 84 is a pilot burner 88, under control of pilot valve 88. Burner 88 serves the a double purpose of,'flrst: igniting gas in heater 84 when gas is supplied to the heater, and second: keeping hot the thermostatic'element 80. Gas reaches burner 88 from pipe I0, through pipe 82, annular passage '84 in valve 88, chamber 88 and pipe 88'. A valve disk I00 pressed upwardly by a spring I02, closes the lower end of passage 84 except when depressed, as in the drawing, by plunger I04 which has a head I08 upon which rests the horizontal arm I08 of a bell crank pivoted at H0 and having a vertical arm H2 in contact with element 80. A bellows I I4 seals plunger,

I04 from the atmosphere. Pipe II8 connects chamber 84 with annular passage 84 in valve 88. When temperature of bulb I0 in the car is at the desired temperature, as indicated on disk 44, lever 84 and its cam roller 40 are in the positions shown in the full lines of the drawing, and the orifice of valve 80 is closed by disk I I8. The disk is mounted on a downwardly extending arm I20 of a cam member I22 pivoted at I24. The cam has an arcuate arm I28 extending to the left and an arcuate arm I28 extending to the right.

If the temperature of bulb I0 should rise above the temperatur desired, bellows I4 will have elongated beyond its normal length, link 82, its upper end actuated by stud 28, will, through pin 88, have moved'the lower end of lever 84 to the left and the upper end thereof to the right, causing roller 40 to push against, and possibly pass over, shoulder I80, thereby rotating cam assembly I22 about its pivot I24 and opening valve 80 by moving arm I20 and disk II8 to their dotted line positions, in which positions they are positively maintained by roller 40 rolling along the top of arcuate arm I28, as indicated by the dotted lines of the drawing. Spring I82 prevents lost motion and back-lash in the cam assembly. While valve 80 is open gas entering instrument case 2I through pipe I8 flows'through pipe 82 into space 84 above diaphragm I4, and thence through pipe II8, through valve 88 and pipe 88 to be burned in pilot burner 88. The pressure of this gas on diaphragm 14, plus the pressure exerted by spring I84, serves to depress the diaphragm until disk I88 attached to the underside of the diaphragm rests on valve seat I88, thus preventing flow of gas from pipe I0, through refrigerator space to cool.

When the car temperature drops below normal, bellows I4 shortens, lever 84 swings to the left, and roller 40 rolls along the arcuate top of arm I28, the center of which is at 88, thus positively holding disk II8 against the inlet opening of valve 80. When this occurs, the gas in pipe 82 and space 84 will exhaust through pipe H8 and valve 88 to be burned at pilot 88. Diaphragm 14, thus relieved of ga pressure above it, is raised by the gas pressure in chamber I2 against spring chamber I2 into supply pipe 88, and extinguish- 0 ing the flame in heater 84, thus permitting the such as to prevent backflow from the pipe 82 into the pipe II8 during the normal operation of the system.

The apparatus is put into operation by manually depressing horizontal arm I08 to open valve I00 and permit gas to flow to pilot 88. After the pilot is burning and element is heated there by, valve I00 remains open and the device operates automatically as described so long as gas is supplied, The device illustrated and described will give sufilciently accurate results for ordinary use, but if the requirements as to accuracy are unusually stringent, the improvements of deGiers Patent No. 2,050,965 may be added to the device herewith illustrated.

It is to be understood that the invention is not limited to the refrigerator car embodiment herein illustrated and described, but may be used in other ways without departure from its spirit as defined by the following claims.

What is claimed is: I 1. Apparatus for controlling temperature in refrigerator car, comprising in combination, a pair of bellows. a floating link difierentially interconnecting said bellows, means causing change oflength of one of said bellows in accordance with change of temperature in said car, manually controllable means for changing the eflective length of the other or said bellows for the purpose of adjusting the temperature to be maintained in the car, a heater for supplying heat to said car, and means under control of said link for controlling said heater.

2. In apparatus useful for controlling temperature in a refrigerator car, in combination, a pair of bellows, a floating link differentially interconnecting said bellows, meanscausing change of length of one said bellows in accordance with change of temperature in the car, manually controllable means for changing the relative eifective length of said bellows for adjusting the temperature to be maintained in the car, heating means for supplying heat to the car, and means under control of said link for controlling said heating means.

3. In combination, a plurality of bellows, control means operated by said bellows and including a floating'link differentially interconnecting two of said bellows, means including a thermally responsive device connected to one of said linkconnected bellows for changing the eifective length of said last mentioned bellows in accordance with changes in temperature at the locus of said thermally responsive device, means responsive to changesin temperature between said locus and said bellows for changing the eflective length of the other of said link-connected bellows, heating mean for supplying heat at the said locus, means under the control of said link for controlling said heating means, and manually settable means for changing the effective lengths of at least one of said bellows for adjusting the temperature to be maintained at the said locus.

' CLARENCE A. m: GIE'RS.

ARTHUR WICKESSER.

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