Vehicle seat belt tensioner

摘要

The vehicle seat belt tensioner has the torque producing device (18) comprising a flexible steel tensioning band (21) which is partly coiled onto the drive roller (22). A band extension chamber (23) is divided into two chambers (23',23") by the tensioning band. Under pressure actuation the band is uncoiled by the rotation of the drive roller. The radial extension of the band chamber is adjustable in the direction of rotation of the drive roller. The radial extension as the band starts to uncoil increases in the direction of rotation from a base coil radial size, and then remains approximately constant or pref. decreases again.