Patent ID: 8042835

Claim:
A belt tensioner for a safety belt system, comprising a drive unit ( 32 ) and; a one-piece power transmission element ( 26 ), which engages on and moves a drive element ( 18 ) when the drive unit ( 32 ) is activated, the power transmission element ( 26 ) engaging the drive element ( 18 ) through the entire path of movement of the drive element ( 18 ), the power transmission element ( 26 ) being a non-rigid medium, the medium being an elastic solid, the power transmission element ( 26 ) having a constant cross-section over its entire length and being received in a hollow section of a guide ( 29 ), said guide having a first portion ( 30 ) and a second portion ( 28 ), said second portion ( 28 ) of the guide receiving the power transmission element ( 26 ) before the drive unit ( 32 ) is activated and being at least substantially filled by said power transmission element ( 26 ) before the drive unit ( 32 ) is activated.