Patent ID: 9145107
Filing Date: 2015-09-29
Classification: B60R

Abstract:
1. A belt tightening drive for tightening a safety belt which can be wound up around a winding shaft, comprising (i) an electric motor, a spindle shaft and an output wheel coupled with the winding shaft, and (ii) a worm gear by way of which the output wheel is driven by the spindle shaft, wherein for the formation of the worm gear an external helical gear of the output wheel is combing with a worm drive supported torsionally rigid on the spindle shaft; further comprising wherein the external gear of the output wheel comprises at least two gear sections, wherein a first gear section comprises a gear with constant geometry and a following second gear section is designed with an increasing root circle diameter, and wherein the second gear section is mounted on the output wheel such that in the event of high passive loads, said second gear section, including the increasing root circle diameter, is pushed toward the worm drive such that a mechanical jamming linkage is created between the output wheel and the worm drive.