Patent ID: 6676161
Filing Date: 2004-01-13
Classification: B60R

Abstract:
A linear pretensioning drive for tightening a vehicle seat belt comprising:a guide tube; a piston that is located inside the guide tube and can be driven along a longitudinal axis of the guide tube in a drive direction; and a reverse movement lock comprising locking elements arranged on a ring around the longitudinal axis of the guide tube, the locking elements, on movement of the piston in an opposite direction to the drive direction, assume a locking position between the piston and the guide tube, which locks the further return stroke of the piston against the drive direction, in the drive direction in front of the reverse movement lock at least one support part is provided which, in the locking position, lies against an inner wall of the guide tube with a greater supporting surface than each locking element of the reverse movement lock, wherein the at least one support part and the reverse movement lock can be moved into the locking position along a tapered surface that is provided on the piston.