Means for securing flexible diaphragm in fluid actuator for valves

Claim 2

A valve and valve actuator assembly comprising, a valve body defining a valve chamber and a fluid passage in communication with the valve chamber, a gate valve mounted within the valve chamber, a stem connected to the gate valve, and a fluid actuator mounted on the valve body for moving said stem and gate valve between open and closed positions, said fluid actuator including a piston connected to said stem, an inner hydraulic cylinder in which the piston is mounted for movement and having opposed end members of a diameter greater than the diameter of said cylinder, said inner cylinder having a hydraulic fluid pressure chamber adjacent the outer side of the piston and a spring adjacent the inner side of the piston to return the piston and gate valve to a closed position, means to supply hydraulic fluid to said fluid pressure chamber to move the piston and gate valve to an open position, an outer cylindrical shroud member mounted on said end members in concentric relation to the hydraulic cylinder and forming an annular chamber between the inner cylinder and shroud member, said shroud member fitting about the outer end member and seating on the inner end member, a diaphragm disposed within the annular chamber adjacent the shroud member and forming a pressure balancing chamber for the inner side of said piston, means providing fluid communication between the annular chamber and the hydraulic cylinder on the inner side of the piston, means communicating the fluid pressure of the fluid medium in which the actuator is positioned outwardly of the flexible diaphragm, each of said end members having an annular outwardly facing groove therein and said shroud member having an opposed inwardly facing groove therein adjacent each end of the shroud member, annular gripping means positioned within each of said shroud member grooves, and means to move the gripping means inwardly when the shroud member is seated on said inner end member to grip the marginal end portions of said flexible diaphragm tightly against the opposed grooves in the end members.

Claim 3

A valve and valve actuator assembly as set forth in claim 1 wherein said annular gripping means comprises a resilient band in each of said shroud member grooves having separated opposed ends.

Claim 4

A valve and valve actuator assembly as set forth in claim 2 wherein radially spaced threaded openings are in communication with each of said shroud member grooves, and said means to move the resilient bands inwardly comprises studs threaded within said threaded openings and pressing the bands inwardly against the flexible diaphragm.

Claim 5

A valve and valve actuator assembly as set forth in claim 2 wherein said annular gripping means comprises a resilient band in each of said shroud member grooves and said means to move the gripping means inwardly contacts the resilient band for the outer end member and moves the resilient band within the associated groove on the outer end member, said resilient band when positioned within said associated groove on the outer end member abutting the adjacent surface defining said groove and thereby preventing outward movement of said shroud member.

Claim 6

A valve and valve actuator assembly comprising, a valve body defining a valve chamber and a fluid passage in communication with the valve chamber, a gate valve mounted within the valve chamber, a stem connected to the gate valve, and a fluid actuator mounted on the valve body for moving said stem and gate valve between open and closed positions, said fluid actuator including a piston connected to said stem, an inner hydraulic cylinder in which the piston is mounted for movement and having opposed end members of a diameter greater than the diameter of said cylinder, said inner cylinder having a hydraulic fluid pressure chamber adjacent the outer side of the piston and a spring adjacent the inner side of the piston to return the piston and gate valve to a closed position, means to supply hydraulic fluid to said fluid pressure chamber to move the piston and gate valve to an open position, an outer cylindrical shroud member mounted on said end members in concentric relation to the hydraulic cylinder and forming an annular chamber between the inner cylinder and shroud member, said outer shroud member fitting about the outer end member and seating on the inner end member, a diaphragm disposed within the annular chamber adjacent the outer shroud member and forming a pressure balancing chamber for the inner side of said piston, means providing fluid communication between the annular chamber and the hydraulic cylinder on the inner side of the piston, means communicating the fluid pressure of the fluid medium in which the actuator is positioned outwardly of the flexible diaphragm, each of said end members having an annular outwardly facing groove therein and said shroud member having an opposed inwardly facing groove therein adjacent each end of the shroud member, said shroud member having a plurality of radially spaced threaded openings communicating with each of the inwardly facing grooves, a resilient band with separated ends mounted within each of the inwardly facing grooves, and studs threaded within said openings when the shroud member is seated on said inner end member contacting and pressing said bands tightly against the flexible diaphragm and the adjacent end members.

Claim 7

A valve and valve actuator assembly comprising, a valve body defining a valve chamber and a fluid passage in communication with the valve chamber, a gate valve mounted within the valve chamber, a stem connected to the gate valve, and a fluid actuator mounted on the valve body for moving said stem and gate valve between open and closed positions, said fluid actuator including a piston connected to said stem, an inner hydraulic cylinder in which the piston is mounted for movement and having opposed end members of a diameter greater than the diameter of said cylinder, said inner cylinder having a hydraulic fluid pressure chamber adjacent the outer side of the piston and a spring adjacent the inner side of the piston to return the piston and gate valve to a closed position, means to supply hydraulic fluid to said fluid pressure chamber to move the piston and gate valve to an open position, an outer cylindrical shroud member mounted on said end members in concentric relation to the hydraulic cylinder and forming an annular chamber between the inner cylinder and shroud member, said outer shroud member fitting about the outer end member and seating on the inner end member, a diaphragm disposed within the annular chamber adjacent the outer shroud member and forming a pressure balancing chamber for the inner side of said piston, means providing fluid communication between the annular chamber and the hydraulic cylinder on the inner side of the piston, means communicating the fluid pressure of the fluid medium in which the actuator is positioned outwardly of the flexible diaphragm, each of said end members having an annular outwardly facing groove therein and said shroud member having an opposed inwardly facing groove therein adjacent each end of the shroud member, said shroud member having a plurality of radially spaced threaded openings communicating with each of the inwardly facing grooves, a resilient band with separated ends mounted within each of the inwardly facing grooves, and studs threaded within said openings when the shroud member is seated on said inner end member contacting and pressing said bands tightly against the flexible diaphragm and the adjacent end members.

Claim 8

A valve and valve actuator assembly as set forth in claim 5 wherein said resilient band adjacent the outer end member when positioned within the adjacent groove for the outer end member prevents outward movement of said shroud member.