| 摘要 |
A belt tightener with a pyrotechnic piston-cylinder drive has a vehicle-sensitive weight which is formed by a pivotably mounted casing block (14), a gas generator (18) inserted into the latter and a piston-cylinder unit (20). In order to ensure that the casing block (14) is freely pivotable, the piston (24) is accommodated in the cylinder (22) with axial and radial play. The piston (24) is provided with an annular groove (50) in which there is arranged an annular seal (52). When not subjected to the pressure of the gas, the annular seal (52) is not in contact with the inside wall of the cylinder (22). The pressure of the gas causes the annular seal (52) to move axially along the conically rising bottom (56) of the annular groove (50) and expand radially at the same time, until it engages with the inside wall of the cylinder (22) in a sealing manner. …<IMAGE>… |
