Belt tightener for vehicle safety belt

摘要

The tightener has at least two drive units (20,21) movable in guides located in a housing. The drive units can be brought into active engagement with a winding shaft of a safety belt winder in a timed sequence and are offset in a belt tightening rotational direction. The tightener has a sun gear (4) rotationally coupled to the winding shaft in order to tighten the belt, and a planet gear (11) which is brought into engagement with the sun gear by action of a coupling unit. In the engaged position, the planet gear follows a circular path of movement about the sun gear. Each drive unit is coupled with the planet gear for a certain movement section of the planet gear, in order to transfer their drive movement.