Belt retractor for vehicle safety seat belt, has pre-load drive and belt winder, where force flows between drive and winder when drive is in one of two motor operating conditions, and power transmission element is in one of two positions

摘要

The retractor (4) has a power transmission element movable between two different positions. Force is limited from flowing between a pre-load drive (10) and a belt winder (8) when the pre-load drive is in a motor operating condition and the power transmission element is in one of the positions, and force flows between the pre-load drive and the belt winder when the pre-load drive is in another motor operating condition, and the power transmission element is in the other position. The power transmission element arrives from the former position into the latter position by abrupt acceleration.