Fluid Actuated Or Retarded Patents (Class 251/12)
- Serial main line cut-off and manual valves (e.g., hydraulic "fuses") (Class 251/16)
- Auxiliary pilot valve overrides a first pilot valve (Class 251/19)
- Forced return of actuator to cut-off position (Class 251/20)
- Actuator connection released on opening of cut-off valve (Class 251/21)
- Control fluid released into closed build-up chamber (Class 251/22)
- Dashpot interconnects actuator and valve (Class 251/23)
- Alternative pressure sources or pilot valve (Class 251/26)
- Servo failure responsive control of main valve (Class 251/27)
- Fluid actuated pilot valve (Class 251/28)
- Electrically actuated pilot valve (Class 251/30.01)
- Double or oppositely acting motor units (Class 251/31)
- Latched pilot valve (Class 251/32)
- Choked pressure type servo motor (Class 251/33)
- With separate dashpot or choked fluid retarder (Class 251/47)