Tensioning drive for a safety belt device

摘要

A tensioning drive for a safely belt device. The tensioning drive includes a gas generator, a drive wheel and a supply pipe which connects the gas generator and the drive wheel. A plurality of pushing members is included in the supply pipe. The pushing members are accelerated after the gas generator has been activated. The pushing members drive the drive wheel, and at least one of the pushing members completely or at least partially seals the supply pipe. The sealing action of the at least one sealing pushing member is ended or reduced after a predetermined distance has been travelled.

主权项

1. A tensioning drive for a safety belt device comprising:
a gas generator; a drive wheel; a supply pipe which connects the gas generator and the drive wheel; a plurality of pushing members provided in the supply pipe; the plurality of pushing members including a sealing pushing member that at least partially seals the supply pipe; and at least one through-hole which extends through the sealing pushing member or between the sealing pushing member and an inner wall of the supply pipe which is sealed by a pushing member located upstream of the sealing pushing member; wherein the tensioning drive is configured so that:
the pushing members are accelerated after the gas generator has been activated in order to drive the drive wheel,the sealing action of the sealing pushing member is ended or reduced after the sealing pushing member has travelled a predetermined distance,the sealing pushing member loses its sealing action when introduced into a bent portion of the supply pipe, andthe sealing pushing member remains fixed at a predetermined location in the bent portion of the supply pipe, and is separated from the pushing member located upstream of the sealing pushing member thereby resulting in the through-hole being unsealed.