Patent ID: 6848644
Filing Date: 2005-02-01
Classification: B60R

Abstract:
1. A belt tensioner of a seat belt for an occupant on a seat in a vehicle, comprising: a retraction device configured to automatically shorten the belt; an extraction lock configured to act in accordance with predetermined parameters; an irreversible tensioning device configured to irreversibly tighten the belt with a powerful force to maintain a desired sitting position of the occupant for a short period of time in response to receipt of a crash signal generated by a sensory system; two parallel clutches; and a retraction motor configured to operate and drive the retraction device, the retraction device one of connected and connectable to the retraction motor by the two parallel clutches, the retraction motor switchable between two power ranges; wherein a first one of the clutches is configured to operate with a constant limited frictional connection to transmit one of a small force and a small torque and a second one of the clutches is arranged as a normally-open clutch and configured to close in response to a high-power range of the retraction motor switched on.