Patent ID: 9145108
Filing Date: 2015-09-29
Classification: B60R,B64D

Abstract:
1. A pretensioner for tightening an occupant restraint, the pretensioner interconnected to an inertial reel, the inertial reel locking the occupant restraint when provided with a locking signal, the pretensioner comprising: a pretensioner body having an internal cylindrical bore with proximal and distal ends, a fluid port at the proximal end and an opening at the distal end, a removable end cap frictionally fitted within the opening; a rack comprising an elongated shaft having proximal and distal ends and upper and lower surfaces, the upper surface portion of the shaft having teeth formed there along, the lower surface of the shaft having a horizontally planar portion and an obtusely angled surface portion adjacent the proximal end, a piston formed at the proximal end of the shaft, a shear pin mounted to the distal end of the shaft, the rack having un-extended and extended orientations; an initiator and pressure chamber housed in said pretensioner body adjacent the proximal end of the bore, the pressure chamber being perpendicular to the bore and in communication with the fluid port, the initiator having an activated state wherein fluid is delivered into the pressure chamber, through the fluid port, and against the piston, whereby the rack is moved from the un-extended to the extended orientation, movement of the rack to the extended orientation severing the shear pin and ejecting the end cap; a pinion held on a pinion shaft rotatably supported within the pretensioner body, the pinion shaft being connectable to the inertial locking reel, the pinion being disengaged from the rack with the rack in the un-extended and extended orientations, the pinion engaging the rack as the rack is moved between the un-extended to the extended orientation; a fixed deceleration ramp positioned within the bore and in slidable contact with the lower surface of the rack, the deceleration ramp having an angled surface in a first orientation, the angled surface of the deceleration ramp interfering with the lower surface of the rack, whereby as the angled surface of the deceleration ramp engages the obtusely angled surface portion of the rack, the rack is slowed prior to reaching the extended orientation and whereby as the rack reaches its extended orientation the fixed deceleration ramp remains in the first orientation and locks the rack in the extended orientation while minimizing bounce back of the rack.