Abstract: Aspects of embodiments of the invention relate to a spring-return actuator comprising a first piston movable between a first and a second position by pressurized fluid to move a load; a safety system comprising a second piston movable by the pressurized fluid to arm the safety system and which returns the first piston from the second position to the first position when de-energizing the 3/2 pilot valve or when the pressure of the pressurized fluid drops below a safety pressure threshold; and a differential fluid channel for providing the pressurized fluid and configured so that the first piston while working to move the load remains substantially disengaged from the safety system being armed.

Abstract: Aspects of embodiments of the invention relate to a spring-return actuator comprising a first piston movable between a first and a second position by pressurized fluid to move a load; a safety system comprising a second piston movable by the pressurized fluid to arm the safety system and which returns the first piston from the second position to the first position when de-energizing the 3/2 pilot valve or when the pressure of the pressurized fluid drops below a safety pressure threshold; and a differential fluid channel for providing the pressurized fluid and configured so that the first piston while working to move the load remains substantially disengaged from the safety system being armed.

Abstract: Actuator controller comprising a body (12) with an inlet port (14) coupled to a source of pressurized fluid and in flow communication with primary and secondary spool bores (16, 20); primary and secondary spools (60, 62); first and second cross flow ports (48, 52) communicating said primary and secondary spool bores, compression and expansion outlet ports (53, 54) for applying pressurized fluid to a return-biased actuator (110); and a venting outlet port (23); wherein return action of the working piston of the actuator is facilitated with aid of pressurized fluid already gained in the system.

Abstract: Actuator controller comprising a body (12) with an inlet port (14) coupled to a source of pressurised fluid and in flow communication with primary and secondary spool bores (16, 20); primary and secondary spools (60, 62); first and second cross flow ports (48, 52) communicating said primary and secondary spool bores, compression and expansion outlet ports (53, 54) for applying pressurized fluid to a return-biased actuator (110); and a venting outlet port (23); wherein return action of the working piston of the actuator is facilitated with aid of pressurized fluid already gained in the system.