Hermetically sealed actuator

摘要

An actuator connected to receive high pressure gas from a pyrotechnic initiator incorporates a primary piston and a secondary piston mounted for limited movement along cylindrical bores in a housing; the pistons are held in a fixed inactive position and are restrained from movement within the housing by a tension screw connected to the primary piston and the housing. The tension screw incorporates a calibrated reduced diameter section that ruptures at a predetermined applied force to permit the pistons to move within the housing. Gaseous products resulting from initiation are trapped and maintained within the housing by an expandable bellows secured internally of the housing at one end of the bellows and secured at the opposite end of the bellows to the interior of the housing. A calibration/test port extends through the housing into the bore externally of the bellows to permit calibration and testing of the actuator without initiating the pyrotechnic device.