Restrictor for refrigeration systems

July 22, 1952

B. H. HUGHES

RESTRICTOR FOR REFRIGERATION SYSTEMS

Filed May 26, 1950

2,604,119

CONDENSER

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EVAPORATOR

INVENTOR.

B.H, H UGHE.5

ATTOmTYS

Patented July 22, 1952

2,604,119

UNITED STATES PATENT OFFICE

2,604,119

RESTRICTOR FOR REFRIGERATION

SYSTEMS

Benjamin H. Hughes, Winston-Salem,N. C.

Application May &lt;26,1950, Serial No. 164,453

Claims.

·..·

My invention relates to a fluid pressure reducing device.

An important object of the invention is to provide an adjustable fluid pressure reducing device or restrictor for refrigeration systems, wherein it is necessary to reduce the pressure of the coolant between the condenser or high pressure side of the system and the evaporator of low pressure side thereof.

A further object of the invention is to provide a restrictor of the above mentioned character, wherein the restricted passage Is formed by the coils of a spring, a casing holding the spring, and a stem passing axially through the spring, the spring being compressed to vary the cross-sectional area of the restricted passage.

A further object of the invention is to provide a restrictor of the above mentioned character which is very easy to adjust, assemble and dismantle.

Other objects and advantages of the invention will be apparent during the course of the following description:

In the accompanying drawings, forming a part of this application, and in which like numerals are employed to designate like parts throughout the same,

Figure 1 is a diagrammatic view of a refrigeration system including a restrictor embodying my invention.

Figure 2 is a greatly enlarged central vertical longitudinal section through the restrictor,

Figure 3 is a horizontal transverse section taken on line'3—3 of Figure 2, and,

Figure 4 is a fragmentary perspective view of a coil spring embodied in the restrictor.

In the drawings, where for the purpose of illustration .is shown a preferred embodiment of my invention, the numeral 10 designates generally a fluid pressure reducing device or restrictor connected in a refrigeration system embodying the usual compressor 11, condenser or radiator 12 and cooler or evaporator 13. In the system, the refrigerant flows from the compressor to the condenser, as shown, and from the condenser into the restrictor 10, by way of a conduit or tube 14. After flowing through the restrictor 10, and having its pressure reduced thereby, the -refrigerant flows through a conduit or tube 15 to the evaporator 13.

The restrictor 10 comprises an elongated cylindrical body or casing it' having a central longitudinal cylindrical recessorbore 12' terminating inwardly of one end I6 of the casing (0 for forming a bottom or shoulder 41. The -opposite end (Cl. 138—43) of the bore 12' opens into an enlarged counterbore or recess 18 formed centrally in an enlarged cylindrical extension or housing 19, integral with the casing 1.0. The counter-bore 18 and bore 12' 5 are concentric, as shown. The counter-bore 18

Opens through the outer end of the head 19 and has its outer portion screw-threaded as shown at 20. A wide flat annular shoulder or seat 21 is provided at the top or open end of the bore 12' 10 by the bottom of the counter-bore 18 and surrounding the bore 12', as shown, A central reduced screw-threaded bore -or -opening 22 is formed in the end 16 and is concentric with the bore 12'. Near and inwardly of the opposite ends 15 of the bore 12', the casing 10 is provided with a pair of longitudinally spaced radial tubular extensions or nipples 23 and 24, integral-therewith, and having inlet and outlet passages or bores 2 5 leading into the bore 12' near its opposite ends. 20 The nipples 23 and 24 are connected with the conduits 14 and 15 respectively by coupling devices 26 of any suitable type.

Mounted within the bore 12' and removable therefrom and ’extending for substantially the 25 entire length of the bore 12' is a resilient spirally wound coil spring 21 formed -of -wire which is rectangular in cross-section. as shown. One end of the spring 21 engages the bottom .or shoulder 11 and-its .opposite end terminates inwardly of or 30 below the seat 21, as at 28. The outside.circumference pf the spring is grounded while thespring •is compressed, to provide an accurate cylindrical form, and the inside circumference-of the spring is grounded when the spring is at its .free length. 35 When the spring 21 is inserted into the bore 12' and the -spring is in its free state or under no •compression, the outside circumference of the spring is slightly smaller than the diameter of the cylindrical bore 12'·, providing an annular clear40 ance 'between the same which may be from .003 to .005 inch. The inside circumference or bore 29 of the spring is accurately ground and is Cylindrical and is concentric with the bore 12' and opening 22, for receiving an elongated straight 45 cylindrical stem or rod 30, which has a close sliding-or liquid tight fit within the cylindrical bore of the spring 21, when the spring is free or elongated. The Stem or rod 30 extends through the entire length Of the spring and has its ’inner 50 end-screw-threaded to engage within the screwthreaded opening 22, as shown. .Adjacent to the outer end of the spring, the stem or rod carries an enlarged cylindrical head 31, integral therewith and slidably -engaging -within .the bore 12' 55 aud its outer end or face 32 is flushwith the seat

2,604,110

2i. The cylindrical head 31 contacts with the adjacent end of the coil spring 27, as shown. A restricted passage 33 is formed by the turns of the coil spring 27, between the periphery of the stem or rod 30 and the bore 12' and this restricted passage 33 is in communication with the bores or passages 25. The restricted passage 33 is continuous and uninterrupted throughout the entire length of the spring so that the liquid refrigerant can pass from the conduit ! 4 to the conduit 15.

Outwardly of the head 31, there is a stem or rod extension 34 having a flat 34' by means of_rwhich the stem or rod 30 may be turned. The extension 34 is in effect a continuation of the stem 30. The extension 34 terminates within the counter-bore 18. ,

A flat compressible sealing gasket or washer 35 ^;surrounds the extension 34 within the counterbore 18 and engages the seat 21 and head 31. A flat washer or disc 35 engages the outer side of the gasket 35, and a flat compression nut 37 is mounted within the screw-threaded portion 20 of the counter-bore 18 outwardly of the washer 36 for tightly clamping the gasket 35 against the shoulder 21 and head 31. A removable screwthreaded cap or plug 38 is provided for the outer end of the head 19, as shown.

In use, with the parts assembled as shown and described, the liquid refrigerant flows from the condenser 12, through the conduit 14 and nipple 23 into the upper end of the restricted passage 33 of the restrictor. The refrigerant passes through the restricted passage 33 and is expanded and is delivered through the conduit 15 to the . evaporator 13 and is returned to the intake side of the compressor,; and passes from the outlet side of the compressor to the condenser 12. This is the usual cycle of operation occurring in a refrigerator. ’ : When it is desired, to vary the cross-sectional area of the restricted passage 33, to reduce the same, the cap 38 is removed, and a tool applied to the square 34' and the stem 39 turned. Since duction of clearance between the outer circumference of the spring and the bore 12'. If the compression of the spring 27 is sufficient, the clearance at the outer circumference of the spring is completely closed. A small amount of the liquid refrigerant will pass through the outer or inner clearances, or both, depending upon the degree of compression of the spring and since these clearances are. much less than the crosssectional area of the. restricted passage 33, the major portion of liquid refrigerant will pass through the restricted passage 33. It is thus apparent that by turning the stem 30, the spring 28 may be compressed, and the cross-sectional area of the restricted passage 33 varied or decreased.

It is to be understood that the form of the invention herewith shown and described is to be taken as a preferred example of the same and that various changes in the shape, size and arrangements of parts-may be resorted to, without departing from the spirit of the invention or the scope of the subjoined claims.