Patent ID: 6113145
Filing Date: 2000-09-05
Classification: B60R

Abstract:
A pyrotechnic pretensioner for a vehicle safety restraint comprising:engaging means for engaging a belt webbing;a cable attached to the engaging means;a piston slidably movable within a cylinder and attached to one end of the cable;driving means for driving the piston along the cylinder to pull the cable and tension the webbing; andlocking means which allows free movement of the piston in the cylinder in a webbing tensioning direction and operates to engage the piston with the cylinder in response to movement of the cable in a webbing loosening direction,wherein the internal surface of the cylinder has a tooth profile cooperating with the locking means and the piston has two circumferential radially extending resilient sealing members for cooperating with the tooth profile to seal the spaces between teeth, wherein the two radially extending sealing members are spaced apart by an odd integral number of half pitches of the teeth.