Motor vehicle occupant seat safety belt tightening drive device

摘要

A device to move components in a motor vehicle, such as to tension one or more safety belts, with a piston guided linearly in a pressure tube has pyrotechnic items which can be ignited one after another to drive the piston. By the linear movement of the piston following a primary ignition, successive ignitions are released for the drive. By the linear movement of the piston, pressure channels (12) are uncovered through which the subsequent ignitions are triggered by the igniter, activated by the pressure. The subsequent ignitions are triggered mechanically. The primary ignition is triggered either electrically or mechanically. In the pressure tube are a single piston and two pistons moving in opposite directions towards the tube ends.