US2577450A

US2577450A - Refrigeration expansion valve

Info

Publication number: US2577450A
Application number: US33719A
Authority: US
Inventors: Franklyn Y Carter
Original assignee: Detroit Lubricator Co
Current assignee: Detroit Lubricator Co
Priority date: 1948-06-18
Filing date: 1948-06-18
Publication date: 1951-12-04
Anticipated expiration: 1968-12-04

Description

Dec. 4, 1951 CARTER 2,577,450

REFRIGERATION EXPANSION VALVE Filed June 18, 1948 as m 35 I8 26 27 4'2 o 36 F5 l3 i ll I INVENTOR. 5W ,QAEL,

By 7 @nwuur M M ATTORNEY Patented Dec. 4, 1951 REFRIGERATION EXPANSION VALVE Franklyn Y. Carter, Dearborn, Mich., asslgnor to Detroit Lubricator Company, Detroit, Mich, a

corporation of Michigan Application June 18, 1948, Serial No. 33,719

11 Claims.

This invention relates to new and useful improvements in refrigeration expansion valves.

One of the objects of this invention is to provide a new and improved expansion valve.

Another object is to provide a "liquid charged" refrigeration expansion valve having a means to close the valve upon excessive pressure therein thereby having an operation similar to that of gas charged valves.

Another object is to provide a thermostatic valve having a means to close the same upon occurrence of a predetermined condition therein and independently of the thermostatic means by which the valve is operated.

Other objects will be apparent from time to time throughout the specification and claims as I hereinafter related.

This invention comprises the new and improved construction and combination of parts and their cooperative relationship to each other which will be described more fully hereinafter and the novelty of which will be particularly pointed out and distinctly claimed.

In the accompanying drawings to be taken as part of the specification, there is clearly and fully illustrated a preferred embodiment of this invention in which drawings the figure is a view in longitudinal cross section of a refrigeration expansion valve embodying this invention.

Referring to the drawings by characters of reference there is a refrigeration expansion valve comprising a valve casing 2 having an inlet fitting 3 and an inlet 4 and an outlet fitting 5 and an outlet 6. Positioned within the casing 2 and screw-threadedly secured in the inlet 4 is a valve seat member 1 forming a valve port and valve seat for admission of fluid to the easing 2. There is a valve member 8 which is screwthreadedly secured to a lever 9 and which is operable upon movement to control flow of fluid through the inlet 4. The casing 2 has an internal projection or abutment H) which functions as a fulcrum point or pivot for the lever B. On the opposite side of the casing 2 from the pivot projection Hi there is an aperture H in which is screw-threadedly secured a plug member l2. The plug member |2 has secured thereon an expansible and contractable bellows member l3 which carries on its movable end wall a fulcrum member or abutment II which is engageable with a recess IS in the lever 9. At the outlet end portion of the casing 2 there is an aperture l1 in the casing wall in which is screw-threadedly secured a plug and guide member I8. The plug and guide member l8 has one or more apertures I9 extending therethrough for passage of refrigerant fluid and has a guide aperture or passageway in which is slidably positioned a thrust rod or pin 20. There is a flexible resilient diaphragm 2| which extends across the open face of the plug and guide member l8 and which is covered or enclosed by a cup-shaped cover member 22 which is held in position by an annular intumed flange portion 23 on the plug and guide member l8. The cover member 22 has an aperture therethrough opening into the space enclosed between itself and the diaphragm 2| in which aperture there is secured a tube 24 leading from a thermostatic bulb element 25. The bulb element 25 contains a volatile liquid and is operable in response to changes in temperature to transmit varying pressures to the space above the diaphragm 2|, which diaphragm responds to differential in pressure on opposite sides thereof. The bulb element 25, the cover member 22, diaphragm 2|, and plug and guide member |8 to gether form a thermostatic power element operable through the thrust member 20 and the lever 9 to control movement of the valve member 8 controlling admission of refrigerant fluid to the casing 2. There is a thrust plate 26 positioned between the diaphragm 2| and the thrust rod 20 which is operable to transmit movement of the diaphragm 2| to thrust rod 20 which in turn is engageable with the end portion 21 of the lever 9 for moving the valve member 8. The downward movement of the lever end portion 2'! by the thrust rod 20 is limited by a projecting portion 2l' which portion projects internally from the casing 2 and functions as a stop member. On the opposite side of the lever end portion 21 from the thrust member 20 there is positioned a helical spring 28 which is held compressively thereagainst and is operable to determine the differential of pressures across the diaphragm 2| which is required to move the lever 9 to control admission of the refrigerant through the inlet 4. There is a supporting member 29 which holds the spring 28 in position against the lever end portion 21 and which is supported by an adjustment screw SI. There is a cover screw H which closes the recess 32 into which the adjustment screw projects. At the inlet end portion of the casing 2 on the side opposite the inlet 4 there is an aperture 33 in which is screwthreadedly secured a plug member 14 which has a spring receiving recess 25 therein. There is a helical spring 38 which is positioned with one end in recess 35 of the plug member 34 and its other end against the end portion 31 of the lever which end portion carries the valve memher I.

In operation this invention functions as 101- lows:

Thereis provided by this invention a liquid charged expansion valve by which a maximum limit of operating pressure maybe obtained as in "gas charged" valves. The bulb element 25 is responsive to changes in temperature and would probably be positioned adjacent the outlet end of the refrigerant evaporator. Changes in pressure in the bulb element 25 resulting from changes in temperature will be transmitted to the space enclosed by the cover member 22 and the diaphragm 2|, and the diaphragm 2| will respond to the differential of pressure between that enclosed by the diaphragm 2| and cover member 22 and the pressure within the casing 2 as admitted through the apertures l9. As the diaphragm 2| is moved downward the thrust rod 20 will transmit this movement'to the lever 9 and rotate the lever in a counter-clockwise direction about the pivot i0 and fulcrum member [4 thereby moving the valve member 8 toward open position. The opening movement of the lever 9 is resisted by the

springs

28 and 36. The compression of the spring 28 may be adjusted by the adjustment screw 30 to determine the temperature of the bulb element 25 at which the valve member will open. The bellows I3 which carries the projection of fulcrum member M is charged with a compressible fluid at a predetermined pressure. As long as the pressure in the casing 2 is below the pressure in the bellows I3 the fulcrum member I will be held compressively against the lever 9 thus holding the same against the pivot ID to form the fulcrum for the lever 9. If the pressure within the casing 2 exceeds the pressure within the bellows iii, the bellows will then begin to collapse and the fulcrum member M will be moved away from the lever 9. As the fulcrum member I4, is moved away from the lever 9, the spring 36, acting directly on the end portion 31 of the lever 9, will move the valve member 8 toward closed position regardless of the position of the end portion 21 of the lever 9.

From the foregoing it should be obvious that there is provided a liquid charged expansion valve which operates through a movable lever to control movement of the inlet valve member for controlling flow of refrigerant therethrough. There is provided in cooperation with the movable lever a movable fulcrum point which is carried by a bellows member which member may be charged with a compressible fluid for response to pressure within the valve casing or which could be charged with a volatile fluid for response to the term perature within the valve casing in the event that the valve was used for a purpose where such a temperature response was desirable. Upon change of a condition of the fluid passing through the valve casing the bellows member is collapsed and the fulcrum member is moved away from the lever to permit the valve member to be moved to a closed position.

Although only one form of this invention has been shown and described, it should be obvious to those skilled in the art that there are numerous variations of this invention which could be made without departing from the scope and intent of this invention.

Having thus described the invention what is claimed and desired to be secured by Letters Patent of the United States is:

1. In a refrigeration expansion valve, a valve casing having an inlet and an outlet, a valve member for controlling fluid flow through said inlet, lever means for moving said valve member and having a fixed fulcrum point for normal operation, thermostatic means for rotating said lever means about said fulcrum point, and means responsive to a condition of the fluid passing through said casing and operable to move said lever means away from said fulcrum point to control movement of said valve member, said responsive means holding said lever means against said fulcrum point during normal operation.

2. In a refrigeration expansion valve, a valve casing having an inlet and an outlet, a valve member for controlling fluid flow through said inlet, lever means for moving said valve member and having a fixed fulcrum point for normal operation, thermostatic means for rotating said lever means about said fulcrum point, and means responsive to pressure of the fluid passing through said casing and operable to move said lever means away from said fulcrum point to control movement of said valve member, said responsive means holding said lever means against said fulcrum point during normal operation.

3. In a refrigeration expansion valve, a valve casing having an inlet and an outlet, a valve member for controlling fluid flow through said inlet, lever means for moving said valve member and having a fulcrum, said lever means being arranged to have lost motion relative to said fulcrum and having an initial position engaging said fulcrum, thermostatic means for rotating said lever means about said fulcrum, and means responsive to a condition of the fluid passing through said casing and operable upon change in said condition beyond a predetermined value to move said lever means away from said fulcrum to control movement of said valve member.

4. In a refrigeration expansion valve, a valve casing having an inlet and an outlet, a valve member for controlling fluid flow through said inlet, a lever carrying said valve member and. operable upon rotation to move the same toward open or toward closed position, a fulcrum for said lever, said lever being arranged to have lost motion relative to said fulcrum, thermostatic means operable to rotate said lever in a valve opening direction, means urging said lever in a valve closing direction, and means responsive to the pressure of the fluid in said casing and operable upon increase in said pressure beyond a predetermined value to move said lever away from said fulcrum and toward valve closed position independently of the position of said thermostatic means.

5. In a refrigeration expansion valve. a valve casing having an inlet and an outlet, a valve member for controlling fluid flow through said inlet, a lever carrying said valve member and operable upon rotation'to move the same toward QJWABO means operable to rotate said lever in a valve opening direction, means urging said lever in a valve closing direction, and means responsive to the pressure of the fluid in said casing and operable upon increase in said pressure beyond a predetermined value to move said fulcrum member, said movement by said last-named responsive means being operable to move said lever away from said pivot and toward valve closed position independently of the position of said thermostatic means.

6. In a refrigeration expansion valve, a valve casing having an inlet and an outlet, a valve port in said inlet, a valve member coooperable with said port to control fluid flow therethrough, a lever carrying said valve member and operable upon rotation in one direction to move the same away from said port, a pivot for said lever, a movable fulcrum member for said lever holding the same against said pivot, said fulcrum member being operable upon movement in one direction to permit movement of said lever away from said pivot and toward said valve port, thermostatic means operable to rotate said lever in said one direction, means urging said lever to rotate in the opposite direction, means responsive to the pressure or fluid in said casing and operable to move the same away. from said pivot thereby upon increase in said pressure beyond a predetermined value to move said fulcrum member in said one direction, and means cooperable with said lever and operable to move said valve member toward said valve port upon movement of said fulcrum member in said one direction.

'7. In a refrigeration expansion valve, a valve casing having an inlet with a valve port therein and having an outlet, a valve member movable toward and away from said port to control fluid flow therethrough, a lever carrying said valve member and operable upon rotation in one direction to move the same away from said port, said casing having an internal projection forming a pivot for said lever, a movable fulcrum member positioned opposite said pivot and holding said lever engaged therewith, said fulcrum member being operable upon movement away from said pivot to permit movement of said lever toward said valve port, a bellows member charged with a compressible fluid under pressure supporting said fulcrum member and urging the same against said lever; a thermostatic power element comprising a flexible resilient diaphragm, a cupshaped member enclosing with said diaphragm a pressure chamber, a thermostatic bulb element charged with a volatile liquid and having a connecting tube opening into said chamber, said diaphragm being exposed on one side to the pressure in said casing and being responsive to the differential of pressure thereacross; a thrust rod operable to transmit movement from the diaphragm of said power element to rotate said lever in said one direction, a helical spring cooperable with said lever and alined oppositely to said power element to resist movement thereby and to urge said lever to rotate in the opposite direction, a second helical spring cooperable with said lever and alined-with said valve member and operable to urge said valve member toward closed position, and said bellows member being operable upon increase of pressure in said casing beyond a predetermined value to move said fulcrum member away from said pivot, said second spring being operable upon said last-named movement to move said valve member toward closed position inde endently of said ower element and said first-named spring.

8. In a refrigeration expansion valve, a valve casing having an inlet and an outlet, a valve member for controlling fluid flow through said inlet, a lever carrying said valve member and operable upon rotation to move the same toward open or toward closed position, a pivot for said lever, a movable fulcrum member for said lever holding the same against said pivot, thermostatic means operable to rotate said lever in a valve opening direction, said thermostatic means including a liquid charged" power element operating through a flexible and resilient diaphragm, said diaphragm being exposed on one side to the pressure in said casing and being responsive to the differential of pressure between said power element and said casing, means urging said lever in a valve closing direction, and means responsive to the pressure of the fluid in said casing and operable upon increase in said pressure beyond a predetermined value to move said fulcrum member, said movement by said last-named responsive means being operable to move said lever away from said pivot and toward valve closed position independently of the position of said thermostatic means.

9. In a refrigeration expansion valve, a valve casing having an inlet and an outlet, a valve member for controlling fluid flow through said inlet, lever means for moving said valve member, a movable fulcrum member for said lever means having a fixed initial position for normal operation, thermostatic means for rotating said lever means about said fulcrum member, said thermostatic means including a liquid charged" power element responsive to temperature ex ternal of said casing and operating through a movable means responsive to pressure in said casing, and pressure responsive means supporting said fulcrum member and operable upon occurrence of a pressure in excess of a predetermined maximum operating pressure within said casing to move said fulcrum member in a direction permitting said valve member to close.

10. In a refrigeration expansion valve, a valve casing having an inlet and an outlet, a valve member for controlling fluid flow through said inlet, lever means for moving said valve member, a movable fulcrum member for said lever means having a fixed initial position for normal operation, thermostatic means for rotating said lever means about said fulcrum member, said thermostatic means including a liquid charged" power element operating through a flexible and resilient diaphragm, said diaphragm being exposed on one side to the pressure in said casing and being responsive to the differential of pressure between said power element in said casing, and pressure responsive means supporting said fulcrum member and operable independently of said power element to move said fulcrum member in a direction permitting said valve member to close upon occurrence of a pressure within said casing in excess of a predetermined maximum operating pressure.

11. A refrigeration expansion valve, comprising a valve casing having an inlet and an outlet and a valve port, a valve member controlling flow through said port, a lever operable to actuate said valve member, spring means urging said lever in a valve closing direction, means responsive to temperature and pressure and acting on said lever to move said valve member, said means being responsive to pressure on the outlet 7 side of said port and including a liquid charged thermostatic power element responsive to temperature external of said valve casing, and means supporting said lever at a normally fixed point for movement by said temperature and pressure 5 responsive means and including means responsive to pressure in said valve casing, said supporting means being moved upon a predetermined maximum pressure in said casing to permit said spring means to move said lever in a 10 valve closing direction.

FRANKLYN Y. CARTER.

8 asmnnoes crrm The following references are of record in the file 01' this patent:

UNITED STATES PATENTS Number Name Date Bosse et al. Sept. 26, 1922 Hilgers Feb. 14. 1933 Otto Mar. 29, 1938 Butler et a1. Dec. 15, 1942 Holmes Oct. 30, 1945 Greenland Sept. 14, 1948