US2259280A - Control device - Google Patents

Description

Oct. 14, 1941. D. D. WILE CONTROL DEvICE Original Filed May 14, 1955 INVENTOR Patented Oct. 14, 1941 CONTROL DEVICE Daniel D. 'Wile, Utica, N. Y., assignor Detroit Lubricator Company, Detroit, Mich., a corporation of Michigan Application May 14, 1935, Serial No. 21,347 -Benewed February 5, 1940 12 Claims.

My invention relates generally to control devices and more particularly to expansion valves. It is an object of my invention to provide a new and improved expansion valve control device for refrigerating apparatus and of a character such that overloading of the refrigerant compressor is prevented during the pull-down to a predetermined degree of .pressure.

Another object of my invention is to provide an expansion valve of the above mentioned character having a new and improved arrangement of the operating parts.

Another object of my invention is to provide a new and improved articulated push rod structure between the valve and valve actuating means of a character to insure proper seating of the valve.

These and other objects of my.invention will be apparent from a reading of the following description taken in connection with the accompanying drawing which forms a part of this specification, and in which drawing- Fig. l is a view shown in side elevation of an expansion valve embodying features of my invention;

Fig. 2 is a view shown in cross-section taken along the line 22 of Fig. 1; W

Fig. 3 is a view shown in cross-section taken along the line 3-3 of Fig. 2, and V Fig. 4 is a view shown partly in cross-section and partly in elevation taken along the line 44 of Fig. 2.

Referring to the drawing by characters of reference, the numeral I designates in general a thermostatic power element which includes a temperature responsive bulb 2, which bulb is arranged, when in operative .position, in heat transfer relation with a refrigerant evaporator (not shown) and preferably at the outlet end thereof. The power element includes a chamber 3 provided, in this instance, by cooperating parts including a cap or casing 4, and connecting the chamber 3 and the bulb 2 there is a tube or conduit 5. A suitable expansible-contractible fluid such as methyl chloride is contained in the bulb 2 and exerts a pressure in chamber 3, which pressure varies in accordance with changes in evaporator temperature at the location of the bulb. The tube 5 may be connected to the cap 4 in any suitable leak-proof manner, such as by providing an aperture in the cap to receive a tubular plug 6 secured thereto and which may be internally threaded to receive the threaded end of the tube 5. In the present instance, the bore through the plug 6 has a portion of enlarged diameter running out of its outer end for receiving a coil spring I which surrounds the conduit 5 and which serves to reenforce the conduit against breakage. Preferably a sealing material such as solder is provided and disposed in the bore of the plug to insure against leakage between the tub and plug.

The cap 4 is removably mounted on one end of a casing or housing [0 which is preferably constructed of a suitable non-heat conducting material, such as Bakelite. The edge defining the open side of the cap 4 is flanged outwardly around its entire periphery as at H, to provide a seating surface for bearing against the circular end wall of the housing l0. Theflange ll also provides a clamping surface for engagement by an inwardly extending flange [2 of a clamping ring I3 which is threaded to the housing In for securing the cap thereto.

Within the cap 4 and disposed adjacent the flanged edge thereof, there is a ring-like wall means I4 disposed in a plane substantially transverse to the side wall of the'cap and which may be welded or otherwise suitably secured thereto.

Disposed within the. chamber 3 there is ariexwith resilient ring members IS in the form of coil springs, there being one positioned in each bend of'the corrugated bellows as is more clearly shown in Fig.4. These springs associated with the bellows I5 serve to prevent the bellows from being collapsed to a point beyond its normal limit of resilience and by so doing prevent fatiguing of the metallic bellows resulting from continued .use and excessive operating pressure, asis well I known in the art.

Carried by the movable and wall I! of the bellows l5 there is a cup-shaped member it which extends from the end wall i'l inwardly through the bellows and preferablyjcentrally thereof, as shown. In the present instance, the cup-shaped member I! is secured to the end wall I! of the bellows by providing an aperture in the end wall I! centrally thereof for receiving an extended portion IQ of the cup-shaped member it which portion is peened over to rigidly secure the parts I together. The inner end of the cup-shaped member I8 has an intumed flange 20, the inner. edge of which defines acentrally located open-.

ing 2|. Through the opening 2| and extending part-way. into the cup-shaped member I8 is one end of a connecting rod 22 of an articulated push 2 rod structure and within the cup-shaped member I8 and adapted to seat on the flange 20 thereof is a bearing or seat member 23 carried by rod 22- and which may be a nut having a,

The inner wall of the housing I8 is formed with an oif-set portion, or portion of larger diameter at its outer end adjacent the cap 4 providing an outwardly facing shoulder 25 extending around its entire periphery. Mounted on the shoulder 25, there is a supporting means which may be a wall means or plate, a at 26, which extends transverse to the side wall of the housing l0 and has a central aperture through which the rod 22 extends. The plate 26, in this instance, has a plurality of resilient spring fingers 21 which may be formed out of the plate and are preferably bent out of the plane of the plate so that when the plate is in operative position the spring fingers extend outwardly or upwardly, as seen on the drawing, and are engaged by the adjacent side of the ring-like member I4 and held under compression thereby. Supported on the plate 26 and within the cap 4 there is a resilient bearing member having a base from which extends a plurality of spring fingers 30 on opposite sides of the cup-shaped member I8. The resilient bearing member may be fixed to the plate 26 in any suitable manner, such as by means of a tubular rivet 3I extending through the apertured plate 26 and a central aperture in the base of the resilient member. The end portions of the spring fingers 30 are preferably curled or rounded with the convex surfaces arranged in engagement with the outer wall of the cup-shaped member I8 to reduce friction between the parts.

Connected to the other or lower end of the housing II), as seen on the drawing, there is a valve casing, designated in general by the numeral 33, which is formed with a tubular extending portion or boss 34 externally threaded for threaded engagement with the internally threaded end portion of the housing "I. The inner wall of the extension 34, at its inner end within housing I0, is formed with a recessed wall 35, the inner side wall 35 defining the recess preferably being circularin contour. The recessed wall 35 provides an annular seating shoulder 'on which is mounted a wall means orplate 36 constituting a closure member which closes the interior of the casing 33 from the interior of the housing I8. Within the housing III and mounted on the closure member 36 there is a sleeve member 31, a portion of one end of which extends into the recessed end of the tubular extending portion 34 and preferably with its outer wall in closefitting relationship with the inner circular side wall 35 of the tubular portion 34.

As indicated at 36, the sleeve member 31 may be welded or otherwise suitably secured to the valve casing. The sleeve member 31 extends from the shoulder 35 into the housing III and is formed on its inner end with an intumed flange 33 extending around its entire periphery, the inner edge of the flange 39 defining a central opening. Within the sleeve member 31 there is a pressure responsive element 46 which may be a substantially cylindrical, circumferentially' corrugated, metallic, resilient bellows. This bellows member, like that of bellows I5, may be provided with the resilient ring member l6, if desired. One end of the bellows 40 is hermetically secured and sealed to the inner side of the fiange 33 of the sleeve 31 around its entire periphery. The other end of the bellows 40 constitutes the free, or movable, end of the bellows and is closed by an end wall member or plate 42 to which it,is secured and hermetically sealed. Thus the movable end wall 42, bellows 40, sleeve 31 and closure member 36 cooperate to form a sealed pressure chamber 43.

The housin III has a transverse wall 45 intermediate its ends and, adjacent which the inner and flanged end of the sleeve member 31 is disposed. The transverse wall 45 may be integral with the housing III, as shown, and this wall is preferably formed with atubular extending portion or apertured protuberance 46 which extends through the opening defined by the flange 38 and into and part-way through the bellows 46 centrally thereof. The inner wall of the tubular portion 46 may be in the form of a bore and preferably the bore has a reduced portion adjacent the transverse wall 45 providing an inwardly facing annular'shoulder 41, or abutment, for one end of a coil spring 48. The other end of the coil spring 48 bears against the movable end wall 42 of the bellows 40, which end wall is provided with an extended portion for receiving and maintaining the end of the spring in proper position. The coil spring 48 is under compression between the transverse wall 45 and the movable end wall 42 of the bellows so that it exerts its force in a direction tending to expand the bellows. The movable'end wall 42 of the bellows 40 is preferably rigidly connected to the connecting rod 22, and this may be accomplished in any suitable manner, such as for example, by means of a plug connecting member 56. The movable end wall 42 of the bellows-40' is apertured centrally thereof for receiving one end of the member 58 which projects therethrough and which is peened over to thus rigidly connect the parts and seal the aperture in the wall 42. The member 50 extends from the movable wall 42 centrally through the spring 48 and is provided with a threaded aperture for receiving the threaded end portion of the rod 22 which extends into the apertured protuberance 46 coaxial with the spring 48.

As previously stated, the sealed chamber 43 constitutes a pressure chamber and this chamber is in communication with the refrigerant evaporator (not shown) such as by means of a connecting tube or conduit 52. The valve casing 33 is provided with a threaded aperture in a wall thereof for receiving a threaded'fitting 53 which extends into the casing and through the closure member 36 into the pressure chamber 43. To the other, or outer end of the fitting 53, one end of the conduit 52 may be suitably connected by means of a nut 54. The other end of the conduit is preferably connected to and in communication with the evaporator and preferably at a point adjacent the location of the thermostatic bulb 2 so that the pressure in chamber 43 substantially corresponds to and varies in accordance with the temperature of the evaporator at its outlet end and the temperature of bulb 2.

The valve casing 33 is formed with apertured bosses 55 and 56 which, in the present instance,

are oppositely disposed and which provide inlet the valve port.

and outlet passages 51 and 58 respectively. The inlet passage 51 isinternally threaded to receive an externally threaded plug 58 which has a centrally disposed recess ,68 for receiving one end of a strainer member 6| mounted therein and extending into the valve casing 33. The outer end of the plug is formed with an externally threaded tubular protuberance 62 for threaded engagement with a nut 63 and clamped between the end of the protuberance 62 and the nut 63 is 10 the flared end of a refrigerant feed or supply conduit 64 leading from a refrigerant compressor '(not shown). The outlet 58 may be connected to the inlet side of an evaporator (not shown) in any suitable manner, such as by means of a nipple or nut (not shown).

Within the valve casing 33, there is a tubularshaped portion 66 which is preferably integral with the casing 33, as shown, and which extends toward the wall 42 and preferably in axial align- 2 ment with the rod 22. The strainer member 6| extends into the casing 33 and its inner end bears against the adjacent outer side wall of the tubular extending member 66 and is-held thereagainst by the plug 59. The interior of the casing 33 is divided by wall means into a highside chamber 81 in communication with the refrigerant supply line 64 and a low side chamber 68 in communication with the refrigerant evaporator. The

dividing wall means includes the tubular mem- 3o with a threaded aperture in axial alignment with 5 the rod 22 for receiving an externally threaded tubular-shaped valve seat member 1!. The valve seat member 7| is formed on one end with an annular flange or head which is disposed within end of the valve seat member is formed with a seat for cooperating with the conical face 12 of a valve member 13. The high side chamber 61 is in communication with the interior of the tubular extension 66 through an openin 15 provided in into the extension 66 and then through the tubular seat member H into the low side chamber 68 from whence it passes into theevaporator by action of the compressor.

Positioned within the tubular extension 66,

there is a reciprocal valve supporting member I? 85 which has a recessed end wall 18 disposed toward the valve 13 and substantially in alignment with The valve 13 extends into therecessed supporting member 11 and seats against the recessed wall 18 which wall is preferably 6|) conical in form, as shown. The valve 13 is preferably cylindrical in shape and the inner end or bearing surface of the valve is preferably spherical in shape. The valve member 13 is not fixedly connected to its supporting means but rather is 88 is clearance for the valve 13 to tilt or cant and 70' .by so doing compensate for inaccuracies which might occur in alignment of the valve and its seat and thus assure proper. seating of the valve. A portion of the valve member 13 extends outwardly of the recessed supporting member II projecting beyond the end wall thereof and preferably, the conical formed end of the valve I3 is truncated, as shown. Centrally of the end wall of the truncated conical shaped valve and longitudinal of the valve there is a bore 88 which extends to a point adjacent the spherical bearing surface where the inner end wall is preferably conical in form to provide a bearing surface for one end of a push rod 8| which rod constitutes a part of the articulated push .rod structure. The other end of the rod 8| engages or bears against a recessed end wall 82 of the plug connecting member 56. The rod 8| extends from the bearing surface 82 of the plug 58,.

through an aperture in plate 36 and through the tubular seat member H and into the bore of the valve 13. The end of the rod 8| bearing against the inner end wall of bore 88 is preferably conical in form. The spherical formed bearing end of the rod, seating in the conical recess, will be held against side movement relative thereto but will permit pivotal movement of the valve member relative to the rod 8|. Preferably, the diameter of the bore 88 is slightly larger than the diameter of the rod 8| to permit movement of the valve member 13. Preferably, the rod 8| is not fixed to either the movable plug member or the valve member 13, but rather is unattached and extends between the plug and valve member with its ends in bearing engagement therewith. By this arrangement, canting or tilting of the rod 8| is permitted to compensate for inaccuracies in bellows construction and alignment of the bellows, valve and valve support for reciprocating action.

The longitudinal passage constituting the valve chamber in the tubular extension 66 may be in the form of a bore 83 which preferably runs out of the casing 33, at the lower end thereof, as

' seen on the drawing, and the bore 83 is also the chamber 61 and abuts the wall 68. The inner 40 preferably enlarged at its outer end portion and internally threaded for receiving the externally threaded shank 88 of a closure plug 85.

or head for bearing against the outer wall of the casing 33 and clamped between the head of the plug and the casing 33 there may be provided a washer to insure a leak-proof joint. The inner end or the closure plug 85 is recessed, as at 81, preferably in the form of a bore and which preferably substantially aligns with bore 83 of the tubular extension 66. Within the recess or bore 81' of the closure plug 85 there is disposed a lineally movable spring supporting means 88 against which one end of a coil spring 98 bears. The coil spring 9|l-is disposed within the tubular extension 66 and extends longitudinally therein surrounding the valve supporting means 11 and having against an annular flange 9| formed on the supporting means 11. Preferably the annular flange 8| is located adjacent the inner end of the valve supporting means, as shown. The coil spring is held under compression between the valve supporting means 11 and the lineally movable seat or support 88 and exerts a force tending to seat the valve.

The lineally movable spring seating member 88 has a tubular portion 93, extending from an annular flange 94, toward and substantially in alignment with the valve port. The periphery of the annular flange 94 substantially conforms to thecontour of the inner wall of the closure plug 85, the inner wall of the closure plug preferably having longitudinally extending slots or keyways for receiving complementary offset portions The closure plug 85 is formed with an annular flange or keys 85': formed on the periphery of the annular flange 84 of which there are two, in the present instance, as shown in Fig. 3 for preventing rotation of the seat member 88. The closure plug 85 has a central aperture therethrough and through which extends a manual adjusting member 88 for the seat member 88. The tubular portion of the seat member 88 is internally threaded for receiving an externally threaded shank portion 81 of the adjusting member 88 which extends through the tubular portion of the seat member 88 and beyond the inner end thereof. The inner end of the shank 81 is provided with an axial bore or recess for receiving the adjacent end of the valve supporting member TI which is reduced in diameter and is slidably guided therein. Thus, the manual adjusting member, through rotation of which the seat member 88 is lineally moved to vary the compression force of the spring, also serves as a guide for the reciprocating valve member 11.

The adjusting member 86 is provided with an annular flange 88 which abuts the inner end wall of the closure plug in a recess formed to receive the same and is held thereagainst by the spring 98. The adjusting member 88 has a reduced portion 88 in the form of a rod or stem which extends from the flange 88, and a portion I88 which extends exteriorly of the casing and may be suitably formed for gripping with a tool to rotate the adjusting member. The outer end of the closure plug 85 has an enlarged bore through which the rod or stem portion 88 extends and in which packing material is preferably provided around the stem 88 under pressure of a packing nut I82 to prevent leakage. A cap I83 is preferably provided to enclose the end of the stem 88 and may be threaded or otherwise se-.

cured to the closure plug 85.

The operation of the expansion valve in connection with a refrigerating system is as follows: When the refrigerant evaporator is relatively warm, such as for example, after the defrosting period, the fluid in the bulb 2, and consequently in the chamber 3, will have expanded and will exert a force against the bellows I5 therein corresponding to the temperature of the evaporator at the location of the bulb 2. Also, in chamber 43 the expanded gas in the evaporator will exert a force against the bellows 48 in accordance with the pressure of the refrigerant in the evaporator. The bellows I5 and 48 oppose each other, the bellows I5 being expansible in a direction tending to open the valve while the bellows 48 is expansible under pressure in chamber 88 in a valve closing direction. During the shut down period the pressures exerted by the gases in chambers 3 and 68 are substantially equal, but

the forces acting on the bellows and the cooperating forces exerted by the springs 48 and 98 are such that the valve is held closed during the shut down period. In the present operation of the expansion valve, instead of the power element l acting to open the valve I3 shortly after the compressor is startedand by so doing' burden the compressor with the additional load of opposing the back pressure of the expanded refrigerant in chamber 88 and in the evaporator, as was the practice in the past, the opening of the valve 13, in the present device, is delayed by a lost motion connecting means operable to actuate the valve only upon decrease of evaporator pressure to a predetermined pressure. For example, the-sum of the forces exerted by the springs '24 and 48 actingto open the valve, minus the opposing is started, the expansion valve will operate as follows during the pull down period: During the shut down period, the bellows I5 will be compressed by the pressure exerted by therelatively warm expansible fluid in chamber 3, but instead of the valve being opened by such movement, the spring 24 absorbs the movement of the bellows and is compressed thereby. When the, bellows I5 compression of the bellows I5. Thus, the travel chamber 3 decreases.

permitted by the stop means and the relative position of the seat 23 determines thecompression force under which the spring is placed. When the compressor has reduced the pressure in the evaporator and therefore in chamber 38 acting against the bellows, to a pressure of lbs., then the forces opposing opening of the valve are equal to those acting to open the valve so that upon decrease in the pressure below 60 lbs, the valve will be opened. Upon a decrease in the pressure of the refrigerant in the evaporator below 60 lbs., the, potential force stored in spring 24 will-expand the spring and acting against the rod 22 in a valve-opening direction, aided by the spring 48, acting against the movable end wall of the bellows 48 will open the valve. The spring supporting member 23, carried by the rod, has moved therewith toward the inner end of the cup-shaped member I8 for seating engagement with the flange of the member I8. The valve now being open, refrigerant flows from the high side chamber'88 to the low side chamber and through outlet 58 to the inlet side of the evaporator. The refrigerant expanding in the evaporator coil first cools the inlet portion of the coil and gradually refrigerates the entire coil in the same manner as the well known automatic expansion valve functions and when the coil is cooled at the point of location of the bulb 2, then the pressure in When the pressure in chamber 3 decreases below a predetermined pressure, the spring 24 expands'the bellows I5, but exerts a substantially constant force onrod 22 until such time as the seating member 23 engages the flange 28 of the member I8. When the member 23 and flange 28 are in engagement, the force exerted on the end wall II of the bellows will be equal to the force exerted on rod 22, or in other words, the spring 24 acts only to maintain'engagement between the member 23 and flange 28. A further reduction in pressure in chamber 3 with a corresponding reduction in force exerted on bellows I5, causes a reduction in force exerted on rod 22 andallows spring 88 to move the valve toward its seat. In other words, after the pressure in chamber 3 is reduced below the predetermined pressure and seat 23 engages stop 28, the

valve operates in the same ,manner as the well 7 0. known thermostatic expansion valve. When the irigerant from being admitted to the evaporator.

The spring fingers 30 engaging the member l8 provide sufficient friction to the reciprocating movement to the valve and cooperating parts to prevent over-travel of such movement and resultant noise commonly known as chattering of the valve. The spring fingers 30 also serve to guide the member I8, and the friction therebetween is only sufficient to provide for an easy movement of the valve and not suiiiciently great so as to appreciably interfere with the throttling of the valve.

What I claim and desire to secure by Letters Patent of the United States is:

1. In a device of the character described, a casing having a port, a valve in said casing controlling flow through said port, resilient means urging said valve in one direction, a supporting means for said resilient means, said supporting means being rotatablyfixed and rectilinearly movable for varying the resiliency of said resilient means, manual adjusting m'eans accessible externally of said casing for rectilinearly moving said supporting means, said manual adjusting means having a recess therein, and a valve carrier member having a recess in one end for receiving said valve and having its other end slidably guided in the recess in said manual adjusting means.

2. In a device of the character described, a casing having a port, a valve in said casing controlling fiow through said port, a coil spring urging the valve in one direction, a movable member bearing against one-end of said spring and movable for varying the force exerted by said spring, a manually rotatable adjusting means in threaded engagement with said movable member, stop means preventing rotary movement of said movable member, said adjusting means having a recessed end wall disposed toward said valve, and a carrier member for said valve, said carrier member having a recessed end wall for receiving said valve and having a reduced end portion slidably guided in the recess in said adjusting means.

3. In a device of the character described, a

casing having a port, a movable supporting means within the casing and having a recess in a wall thereof in alignment with and disposed toward said port, said means having an elongated reduced diameter portion, a loosely disposed valve having one end within said recess and bearing against the recessed wall and the other end disposed for cooperation with said port, said valve having a recessed end wall disposed toward said port, means for urging said valve in one direction, a loosely disposed elongated rod member operatively connected to said second named means and extending through said port and engaging the recessed wall of said valve, guide means having a recess for receiving said portion and cooperable therewith to limit movement of said supporting means, a supporting means carried by said guide means and movable relative to said guide means, and resilient means having one portion thereof adjustably carried by said last-named supporting means for urging said valve supporting means in the opposite direction and maintaining operative connection between said valve and said secondnamed means. A

4. In an expansion valve for controlling the admittance of a refrigerant medium to an evaporator, a casing through which the refrigerant flows enroute to the evaporator, a valve in said casing for controlling flow therethrough, means including a movable member responsive to evaporator pressure for moving said valve toward closed position, a bellows member having a wall movable in response to evaporator temperature, a housing member disposed within said bellows and carried by said movable wall, a wall means disposed intermediate said valve and said housing member and having an aperture therethrough, said housing member having an end wall disposed toward said wall means and pro-.

vided with an aperture aligning with the ,aperture in said wall means, a connecting member connected to said valve. and extending through 'said apertures into said housing member, said connecting member having an annular flange disposed within said housing member and engageable with" one side of said housing end wall to limit movement of said bellows in one direction, and a coil spring disposed in said housing member with one end abutting said movable wall means and its other end abutting the other side of said flange, said spring being compressed by said bellows member upon increase in evaporator temperature and having a force stored therein tending to move said valve toward open position, said wall means limiting movement of said movable wall to store a predetermined force in said spring to determine the evaporator pressure at which said valve will be moved to an open position.

5. In an expansion valve for. controlling the admittance of a refrigerant medium to an evaporator, a casing through which refrigerant flows enroute to the evaporator, a valve in said casing for controlling flow therethrough, a bellows member operable to actuate said valve and having a movable wall, a cap member enclosing said bellows member and detachably secured to a wall of said casing, a removable wall means disposed and clamped between said cap member and said casing wall and having an aperture therethrough, a connecting member extending through said aperture and operatively connecting said valve and said movable wall of said bellows member, and spring fingers formed out of said removable wall, said spring fingers being held under tension by said cap member to hold said removable wall in fixed position relative to.

said casing and said cap member.

6. In an expansion valve for controlling the admittance of a refrigerant medium to an evaporator, a casing through which the refrigerant flows enroute to the evaporator, a reciprocal valve in said casing for'controlling flow therethrough, resilient means supporting said valve, means responsive to a fluid characteristic and having a movable member operable to actuate said valve, a cap member enclosing said responsive means and secured to a wall of said casing, a removable plate member clamped between said cap member and said casing wall, said plate member having an aperture therethrough, a connecting member extending through said aperture and operatively connecting said valve and said movable member, andsprlng fingers carried by said removable plate member and cooperable with said movable member to dampen vibration of said resiliently mounted valve.

7. In an expansion valve for controlling the admittance of a refrigerant medium to an evaporator, a casing through which the refrigerant flows enroute to the evaporator, a resiliently trolling flow therethrough, a movable wall means responsive to a characteristic of the refrigerant I for actuating said valve and secured to a wall of said casing, a fixedfwall means, disposed between said valve and said responsive means, said fixed wall means having an aperture therethrough, an articulated push rod structure connected to said valve and extending through said aperture, a coil spring having one end abutting saidmovable wall and having its other end abutting said push rod structure, said movable wall being movable to compress said coil spring to store a force therein acting through said push rod structure to actuate said valve, stop means carried by said movable wall and cooperable with said fixed wall to limit movement of said movable w'all to store a predetermined force in said spring, and spring fingers supported on said fixed wall and cooperable with said stop means for dampening vibration of said resiliently mounted valve.

8. In a device of the character described, a casing, a valve controlling fiow through said casing, means for actuating said valve including resilient means, a supporting means for said resilient means, said supporting means being rotatably fixed and rectilinearly movable for varying the resiliency of said resilient means, manual adjusting means accessible from externally of said casing for rectilinearly moving said supporting means, said manual adjusting means having a recessitherein, and a valve carrier member having a recess in one end in which the valve member is universally supported and having its other end slidably guided in the recess in said manual adjusting means.

9. In a, valve of the character described, a casing having a passageway therethrough including a valve port, said casing having a side wall opening alined with said port, a rigid plate member sealed within said Opening and having a guide aperture therethrough alined with said port, a tubular member projecting from said casing at said opening, a bellows member within said tubular member and having its outer end sealed thereto, a head member closing and sealing the inner end of said bellows member,

said members cooperating to form a pressure chamber, means for subjecting said chamber to changes in fluid pressure, a valve member on the opposite side of said port from said plate member and having an aperture opening toward said port, a thrust rod slidably fitting and uided in said first-named aperture and extending through said port, said rod having one end engaging said head member and having its other I end received by said valve member aperture, a

housing secured to said casing and surrounding said pressure chamber, said housing. including temperature responsive means, a thrust member connecting said temperature responsive means to said head member, and resilient means urging said valve member toward said port.

10. In a valve .of the character described, a casing having a passageway therethrough including' a valve port, a valve member having a longitudinal recess opening through one end of said member, a supporting member movable toward and from said port and having a longitudinal recess opening toward said port, said supporting member recess having adjacent its inner end an annular converging or tapering bearing surface, said valve member having an annular rounded bearing surface engageable with said first-named annular surface so that said valve member can adjust itself relative to said port upon engagement with its port seat; said valve member recess terminating substantially at the center of curvature of said rounded bearing surface, and means acting on said valve member at the termination of said valve member recess to exert a force so that said valve member will be held in stable frictional engagement with said supporting member in any set position.

11. In a valve structure, a member having a port, a valve carrier movable toward and from said port and having a socket facing said port, a valve member having a hollow portion and being laterally movable in and extending from said socket, said socket being elongated and having a converging internal wall portion at the inner end of said socket and facing said port so that said valve member is limited in its lateral movement by the side walls of said socket, the inner end portion of said valve member having an annular rounded portion engaging said wall portion for universal movement, and means within said hollow portion acting substantially at the center of curvature of said annular rounded portion and holding said inner end portion of said valve member in stable frictional engagement with said wall portion irrespective of the relative position of said valve member and said carrier member within the limits of movement of said valve member.

12. A thermostatic expansion valve for refrigeration systems having an evaporator and comprising, a valve casing having a passageway therethrough, a valve member in said casing and operable to control fiow of refrigerant through said passageway, a pressure responsive element operatively connected to said valve member and responsive to pressure or. the outlet side of said valve member, a temperature sensitive forcetransmitting power element operable to respond to the temperature of the outlet of the evaporator, spring means acting in positive force transmitting relation uponsaid valve member and said pressure element and acting in cooperation with said pressure and power elements to determine the pressure reduction on said element at which said valve member will open, means interposed between said pressure and power elements and. operable to transmit both compressive and tensilev forces from said power element to said pressure element, said interposed means comprising cooperable relatively movable and engageable abutment members carried respectively by said elements, and a spring holding said abutment members in engagement at forces of said power element corresponding to temperatures below a predetermined temperature of the evaporator outlet, said spring being flexed by the force of said power element corresponding to increase in the temperature of the outlet above said predetermined temperature so that said abutment members will be moved out of engagement with each other thereby to allow movement of said valve member by said pressure element irrespective of said power element and ex erting a force of substantially negligible variation within its range of fiexure, said spring acting upon temperature decrease of the outlet toward said predetermined temperature to move said power element abutment member toward said pressure element abutment member without effectively altering the position of said valve member.

' DANIEL D. WILE.

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