Safety control valve system for fluid actuated devices

Claim 1

In a safety control valve system for fluid actuated devices, housing means having a supply port, an outlet port and at least one exhaust port, first and second main valve means in said housing means, each main valve means having supply and exhaust valve members and being shiftable between an open position in which its supply valve member is open and its exhaust valve member closed, and a closed position in which its exhaust valve member is open and its supply valve member is closed, means connecting the supply valve members of said first and second main valve means in series between said supply and outlet ports, means connecting the exhaust valve members of said first and second main valve means in parallel between said outlet and exhaust ports, whereby movement of either main valve means to its closed position when the other main valve means remains partially or fully in its open position will result in a complete cutoff of fluid pressure from the supply to the outlet port and a direct connection from the outlet port to the exhaust port, fluid pressure actuated means directly connected to both valve members of each main valve means for simultaneously shifting both valve members from one position to the other position, resilient means constantly urging both members of each main valve means in the opposite direction, at least one main valve means being so constructed that its fluid pressure actuated means will shift it from its open position to its closed position and its resilient means will shift it from it''s closed position to its open position, and a solenoid operated pilot valve for each main valve means, each pilot valve being so constRucted that it will maintain its main valve means in its closed position when the solenoid is de-energized.