Patent ID: 7114697

Claim:
A quick-acting valve actuator comprising: an actuator body; and a valve actuator member movable in the actuator body between a valve closed position and a valve open position; the actuator further comprising: a drive device in the actuator body; a driven member driven by the drive device relative to the actuator body, the drive device being suitable for causing the driven member to pass via a first stroke to a first trigger position; prestress means for prestressing the actuator member relative to the driven member in order to exert a repulsion force thereagainst when the driven member passes along its first stroke to its first trigger position, said force tending to cause the actuator member at least to pass from a first determined position selected from the valve-open and valve-closed positions to the second determined position selected from the valve-open and valve-closed positions; and locking-and-trigger means stationary relative to the actuator body and co-operating with the driven member and the actuator member so that: during the first stroke, the actuator member is stationary in the first determined position relative to the locking-and-trigger means and the driven member moves relative to the locking-and-trigger means; and when the driven member reaches the first trigger position, the driven member is stationary relative to the locking-and-trigger means and the actuator member is urged by the prestress means relative to the locking-and-trigger means so that the actuator member passes from the first determined position to the second determined position.