US3414014A

US3414014A - Expansion valve

Info

Publication number: US3414014A
Authority: US
Inventors: Merchant Leo Francis; Grahl Darwin Robert
Original assignee: AMERICAN AND STANDARD Inc
Current assignee: AMERICAN AND STANDARD Inc
Priority date: 1965-03-23
Filing date: 1965-03-23
Publication date: 1968-12-03
Anticipated expiration: 1985-12-03

Description

Dec. 3, 1968 ERC A T ET AL 3,414,014

EXPANSION VALVE Filed March 25, 1965 Aqxxw 65 FlG-E INVENTORS L60 F Make/muz- 04PM A? Gem/4 United States Patent 3,414,014 EXPANSION VALVE Leo Francis Merchant, Southfield, and Darwin Robert Grahl, Lincoln Park, Mich., assignors to American & Standard Inc., a corporation of Delaware Filed Mar. 23, 1965, Ser. No. 442,039 1 Claim. (Cl. 137-559) This invention relates to refrigerant expansion valves, and particularly to valves having desired features of low cost and long service life.

One object of the invention is to provide an expansion valve having an improved means for adjusting the superheat setting of the valve.

Another object is to provide an expansion valve having an inspection located to afford visual indication of insufiieient refrigerant charge or improper operation of the valve element.

A further object is to provide an expansion valve having a compact low cost arrangement of parts which affords the dual advantages of superheat adjustment and refrigerant charge inspection.

Other objects of this invention will appear from the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

In the drawings:

FIGURE 1 is a sectional view taken through one embodiment of the invention;

FIG. 2 is a view having a portion thereof taken as a sectional view on line 2--2 in FIG. 1.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

In the drawings there is shown a refrigerant expansion valve in the form of a forged brass housing having a central elongated body portion 12, a first boss 16 extending right angularly from portion 12 adjacent one of its ends, and a second boss 18 extending right angularly from portion 12 adjacent its midpoint. Boss 16 is internally machined to provide a cylindrical inlet passage 20 which intersects a cylindrical inlet chamber 22 machined in an end of body portion 12. Located Within chamber 22 is a spherical valve element 25 having a welded connection with a stem 26, said stem extending through a port or passage 28, and being slidably supported in a guide formed by a hollow annular boss 29. As shown in the drawing, boss 29 projects into a cylindrical cavity 30 machined in the end of body portion 12 remote from inlet chamber 22.

Positioned on an end of body portion 12 is a power element comprising a pair of

fixed plates

32 and 33, and an interposed corrugated metal diaphragm 36, preferably constructed as shown in US. Patent 3,021,108. Plate 33 mounts one end of a tube 35 which extends away from the valve to a temperature sensing bulb (not shown). Thus, an increasing sensed temperature effects an expansion of the bulb fluid, and a movement of the diaphragm toward port 28. The diaphragm movement is transmitted through stem 26 to valve element 25 to thus open port 28 and .permit refrigerant flow into cylindrical'outlet passage 38.

To provide a variable superheat setting for the valve we utilize a compression spring 50 between a first adjust- 3,414,014 Patented Dec. 3, 1968 able spring seat member 52 and a second spring seat member 53 carried by stem 26. Members 52 takes the form of a tubular sleeve 55 having an inwardly radiating flange 57 at the end thereof remote from diaphragm 36. As shown in FIG. 2, sleeve 55 may be factory adjusted axially by a set screw 59 threaded into a tapped hole extending at an acute angle to the axis of stem 26. After the factory adjustment the screw can be concealed by a ball 60, preferably retained by soldering. It will be seen that adjustment of screw 59 can be used to provide a desired loading on spring 50 for thus adjusting or determining the superheat setting of the valve. In the illustrated valve, spring retainer 53 is located in spaced relation to diaphragm 36. However the diaphragm pressure pad 57 could be used as a spring retainer in the event that some means were provided to affix stem 26 to the diaphragm. In most instances the stem merely abuts against the diaphragm pad, and it is therefore not possible to use the pad as a spring retainer.

In the illustrated valve the cylindrical inlet chamber 22 is closed by an inspection window 62 comprised of a glass disc 63 fused into a steel ring65. The ring-disc assembly is held against an O -ring seal 66 by a staked over portion 68 of the valve body. Inspection window 62 is especially beneficial in its illustrated location since it affords visual indication of the liquid refrigerant and the spherical valve element. Thus, the detected presence of bubbles in the inlet chamber liquid will denote insuflieient refrigerant charge. Visual inspection of the valve element while the valve is in service may disclose the presence of dirt, ice or sediment which can prevent proper closing. It can also disclose an improperly charged thermostatic bulb since an insufficiently charged bulb will result in loss of control of the valve element by the power element diaphragm 36, as by failure of the valve element to open in response to an increasing sensed temperature.

It will be noted that the illustrated valve incorporates a novel arrangement of superheat adjustment and inspection window. The window occupies a most advantageous functional position in the valve, and at the same time serves as a closure for chamber 22, thereby adding little to the valve cost. Due to the fact that diaphragm 36 and window 62 occupy opposite ends of the valve housing it is not practical to provide a superheat calibration mechanism along the valve stem axis. However by using a set screw 59 at an acute angle to the stem axis we are able to provide the desired calibration at fairly low cost and without increasing the valve size. Thus, a two tone capacity valve operating on R-12 refrigerant can have a dimension in the direction of stem 26 on the order of two inches or less.

It will be seen from the above discussion that the invention is concerned principally with inspection window 62 and superheat adjustment means 59, said invention being capable of some modification and parts redesign varying from the specifically illustrated construction without departing from the spirit thereof as contemplated by the appended claim.

What is claimed:

1. A refrigerant expansion valve comprising a one piece valve housing having a central elongated body portion defining an axis; a first boss extending right angularly from the central portion adjacent one of its ends, and a second boss extending right angularly from the central portion adjacent its midpoint; a first parallel Walled liquid inlet passage extending within the first boss on an axis at right angles to the body portion axis; a parallel walled liquid inlet chamber extending into said one end of the central body portion on the body portion axis to intersect the inlet passage; a parallel walled vaporous outlet passage extending within the second boss and the midportion of the central body portion on an axis at right angles to the body portion axis; a parallel walled cavity extending axially into the end of the body portion remote from the inlet chamber; the central body portion having an annular boss of appreciable length projecting axially within the cavity to form an elongated stem guide; said central body portion having a flow passage extending between the inlet chamber and outlet passage in axial alignment with the stem guide; a valve element of appreciably less diameter than the lateral dimension of the liquid inlet chamber, said valve element being located in said liquid inlet chamber for movement toward and away from the flow passage to control flow through the valve; :1 thermostatic operator including a diaphragm extending across the cavity in the central body portion for movement toward the inlet chamber on temperature increase; an operator stem extending from the diaphragm through the stern guide and flow passage to operate the valve element; a compression coil spring operatively disposed in the valve housing for urging the stern in a direction tending to 20 close the valve element; and a transparent planar inspection window located in the end of the central body portion remote from diaphragm; said window extending in a plane normal to the stern axis and constituting an end wall for the inlet chamber whereby to afiord a visual indication of insufiicient refrigerant charge or improper operation of the valve element; the diameter of the window being substantially the same as the diameter of the inlet chamber, whereby to afford a view of the entire chamber space.

References Cited UNITED STATES PATENTS 1,952,683 3/1934 Resek et al. 23699 2,246,148 6/1941 Stephenson 62222 X 2,771,092 11/1956 Schenk 25161 X 1,022,327 4/1912 Nelson 25161 2,625,178 1/1953 Price 25161 2,829,836 4/1958 MacKenZie 137-559 X 2,941,712 6/1960 Cook 137559 X 3,021,108 2/1962 Noakes 251-61 3,139,903 7/1964 Lonn 137-559 HENRY T. KLINKSIEK, Primary Examiner.

Claims

1. A REFRIGERANT EXPANSION VALVE COMPRISING A ONE PIECE VALVE HOUSING HAVING A CENTRAL ELONGATED BODY PORTION DEFINING AN AXIS; A FIRST BOSS EXTENDING RIGHT ANGULARLY FROM THE CENTRAL PORTION ADJACENT ONE OF ITS ENDS, AND A SECOND BOSS EXTENDING RIGHT ANGULARLY FROM THE CENTRAL PORTION ADJACENT ITS MIDPOINT; A FIRST PARALLEL WALLED LIQUID INLET PASSAGE EXTENDING WITHIN THE FIRST BOSS ON AN AXIS AT RIGHT ANGLES TO THE BODY PORTION AXIS; A PARALLEL WALLED LIQUID INLET CHAMBER EXTENDING INTO SAID ONE END OF THE CENTRAL BODY PORTION ON THE BODY PORTION AXIS TO INTERSECT THE INLET PASSAGE; A PARALLEL WALLED VAPOROUS OUTLET PASSAGE EXTENDING WITHIN THE SECOND BOSS AND THE MIDPORTION OF THE CENTRAL BODY PORTION ON AN AXIS AT RIGHT ANGLES TO THE BODY PORTION AXIS; A PARALLEL WALLED CAVITY EXTENDING AXIALLY INTO THE END OF THE BODY PORTION REMOTE FROM THE INLET CHAMBER; THE CENTRAL BODY PORTION HAVING AN ANNULAR BOSS OF APPRECIABLE LENGTH PROJECTING AXIALLY WITHIN THE CAVITY TO FORM AN ELONGATED STEM GUIDE; SAID CENTRAL BODY PORTION HAVING A FLOW PASSAGE EXTENDING BETWEEN THE INLET CHAMBER AND OUTLET PASSAGE IN AXIAL ALIGNMENT WITH THE STEM GUIDE; A VALVE ELEMENT OF APPRECIABLY LESS DIAMETER THAN THE LATERAL DIMENSION OF THE LIQUID INLET CHAMBER, SAID VALVE ELEMENT BEING LOCATED IN SAID LIQUID INLET CHAMBER FOR MOVEMENT TOWARD AND AWAY FROM THE FLOW PASSAGE TO CONTROL FLOW THROUGH THE VALVE; A THERMOSTATIC OPERATOR INCLUDING A DIAPHRAGM EXTENDING ACROSS THE CAVITY IN THE CENTRAL BODY PORTION FOR MOVEMENT TOWARD THE INLET CHAMBER ON TEMPERATURE INCREASE; AN OPERATOR STEM EXTENDING FROM THE DIAPHRAGM THROUGH THE STEM GUIDE AND FLOW PASSAGE TO OPERATE THE VALVE ELEMENT; A COMPRESSION COIL SPRING OPERATIVELY DISPOSED IN THE VALVE HOUSING FOR URGING THE STEM IN A DIRECTION TENDING TO CLOSE THE VALVE ELEMENT; AND A TRANSPARENT PLANAR INSPECTION WINDOW LOCATED IN THE END OF THE CENTRAL BODY PORTION REMOTE FROM DIAPHRAGM; SAID WINDOW EXTENDING IN A PLANE NORMAL TO THE STEM AXIS AND CONSTITUTING AN END WALL FOR THE INLET CHAMBER WHEREBY TO AFFORD A VISUAL INDICATION OF INSUFFICIENT REFRIGERANT CHARGE OR IMPROPER OPERATION OF THE VALVE ELEMENT; THE DIAMETER OF THE WINDOW BEING SUBSTANTIALLY THE SAME AS THE DIAMETER OF THE INLET CHAMBER, WHEREBY TO AFFORD A VIEW OF THE ENTIRE CHAMBER SPACE.