Safety valve

Claim 2

A valve assembly comprising a main valve and an auxiliary valve, means biasing said main valve toward a closed position, a diaphragm one side of which is exposed to working pressure and the other side of which is exposed to a reference pressure, and a valve-operating member engageable with said main valve and movable with said diaphragm between two limiting positions within which said main valve is opened by said operating member of closed under the action of said biasing means, said valveoperating member engaging said auxiliary valve whereby to close said auxiliary valve upon movement of said operating member to either of said two limiting positions.

Claim 3

A valve assembly comprising: a. a chamber adapted to fluid flow therethrough, b. a main valve for controlling fluid flow into said chamber, means biasing said main valve toward a closed position, c. an auxiliary valve for controlling fluid flow out of said chamber, and having a first closed position, an intermediate open position and a second closed position, d. a diaphragm closing one end of said chamber one side of which is exposed to working pressure and the other side of which is exposed to a diaphragm biasing means, and e. a valve operating member engageable with said main and auxiliary valves and movable with said diaphragm whereby to move said auxiliary valve to said open position or to one of said closed positions in response to variations in pressure on said diaphragm and whereby to open said main valve against the action of said main valve biasing means or release said main valve for closure by said main valve biasing means.

Claim 4

A valve assembly comprising: a. a chamber adapted to fluid flow therethrough, b. a main valve for controlling fluid flow into said chamber, means biasing said main valve toward a closed position, c. an auxiliary valve for controlling fluid flow out of said chamber, and having a first closed position, an intermediate open position and a second closed position, d. a diaphragm closing one end of said chamber one side of which is exposed to working pressure and the other side of which is exposed to a diaphragm biasing means, and e. a valve operating member engageable with said main and auxiliary valves and movable with said diaphragm whereby to move said auxiliary valve to said open position or to one of said closed positions in response to variations in pressure on said diaphragm and whereby to open said main valve against the action of said main valve biasing means or release said main valve for closure by said main valve biasing means.

Claim 5

A valve assembly defined in claim 2 wherein said main valve comprises a poppet and a poppet seat and said main valve biasing means comprises a spring acting on one side of said poppet to urge said poppet against said seat, said operating means being engageable with the other side of said poppet to urge said poppet away from said seat.

Claim 6

A valve assembly as defined in claim 2 wherein said auxiliary valve comprises two axially spaced annular seats, two double-acting valve members each engageable with one of said seats upon movement of a predetermined distance in either direction, and an outlet from said chamber disposed between said seats.

Claim 7

A valve assembly as defined in claim 2, wherein said auxiliary valve comprises two axially spaced annular seats, an outlet from said chamber disposed between said seats, and two double-acting valve members mounted on said valve-operating member, each of said valve members being engageable with one of said seats upon movement of a predetermined distance in either direction whereby to close said outlet.

Claim 8

A valve assembly as defined in claim 2, wherein said diaphragm-biasing means comprises a compression spring acting against one side of said diaphragm.

Claim 9

A valve assembly as defined in clAim 2, wherein said diaphragm-biasing means is atmospheric pressure acting on said diaphragm outside of said chamber.

Claim 10

A valve assembly comprising a chamber adapted to fluid flow therethrough, a main valve controlling fluid flow out of said chamber consisting of a poppet valve and seat therefore, means resiliently biasing said poppet valve towards said seat, an auxiliary valve arranged to control fluid flow from said chamber consisting of two annular valve seats disposed in axial alignment with the seat of said main valve and two double-acting valve members, each engageable with one of said annular seats upon movement of a predetermined distance in either direction, a diaphragm closing one end of said chamber and having one side exposed to working pressure and the other side exposed to biasing means, a valve operating member engageable with said poppet and movable with said diaphragm between two limiting positions within which said poppet is spaced from said poppet seat or urged against said poppet seat under the action of said poppet valve biasing means, said valve-operating means carrying said double-acting valve members whereby to urge said double-acting valve members against said annular valve seats upon movement of said operating member to either of said two limiting positions.

Claim 11

A valve assembly comprising a chamber adapted to fluid flow therethrough, a main valve controlling fluid flow out of said chamber consisting of a poppet valve and seat therefore, means resiliently biasing said poppet valve towards said seat, an auxiliary valve arranged to control fluid flow from said chamber consisting of two annular valve seats disposed in axial alignment with the seat of said main valve and two double-acting valve members, each engageable with one of said annular seats upon movement of a predetermined distance in either direction, a diaphragm closing one end of said chamber and having one side exposed to working pressure and the other side exposed to biasing means, a valve operating member engageable with said poppet and movable with said diaphragm between two limiting positions within which said poppet is spaced from said poppet seat or urged against said poppet seat under the action of said poppet valve biasing means, said valve-operating means carrying said double-acting valve members whereby to urge said double-acting valve members against said annular valve seats upon movement of said operating member to either of said two limiting positions.