Abstract: A failsafe module comprising an input member (310), an output member (312), and a coupling mechanism for coupling the input member to the output member. The coupling mechanism comprises an intermediate member (316a) movable relative to the output member to energise an energy storage device and a latch mechanism (318, 320) to hold the energy storage device in an energised state. When the latch mechanism is engaged, the input and output members are coupled together and the energy storage device is held in an energised state and isolated from the coupling between the input and output members. When the latch mechanism is released, the energy storage device can release its energy to drive the output member to a predetermined position.

Abstract: A failsafe module comprising an input member (310), an output member (312), and a coupling mechanism for coupling the input member to the output member. The coupling mechanism comprises an intermediate member (316a) movable relative to the output member to energise an energy storage device and a latch mechanism (318, 320) to hold the energy storage device in an energised state. When the latch mechanism is engaged, the input and output members are coupled together and the energy storage device is held in an energised state and isolated from the coupling between the input and output members. When the latch mechanism is released, the energy storage device can release its energy to drive the output member to a predetermined position.

Abstract: The present invention provides a motorized valve actuator wherein the drive from the motor to the output shaft of the actuator is via a worm and worm wheel or other gear mesh which is incapable of being back driven, the actuator having an alternative manual drive, the manual drive comprising a hand wheel and a clutch and lever to change from motor power drive to hand drive mode, the actuator further having an intermediate shaft between the motor and output shaft, the hand wheel being carried by or at least operatively linked to the intermediate shaft to drive the intermediate shaft, the clutch mechanism being associated with/mounted on the intermediate shaft, the intermediate shaft being positioned between the motor and the worm/worm wheel drive whereby the clutch mechanism associated with/mounted on the intermediate shaft operates substantially freely when the lever is operated to bring the actuator into hand drive mode, the output shaft torque generated by the previous motor powered run and locked into the