Patent ID: 7500632
Filing Date: 2009-03-10
Classification: B60R

Abstract:
1. A seat belt device comprising: a gas generator for generating a high pressure gas when a vehicle is in emergency; a cylinder for conducting the high pressure gas from the gas generator; a piston received movably within the cylinder and pressed and moved by the high temperature and pressure gas; a drive unit for rotating a winding shaft of a seat belt retractor in a direction of removing a slack of a belt, using the movement of the piston; an energy absorbing mechanism, for reversely rotating the winding shaft when a tension acting on the belt exceeds a predetermined value after removing the slack of the belt; and a venting mechanism having a gas passageway for exhausting the high temperature and pressure gas from a space filled with the high temperature and pressure gas to the outside of the space, wherein gas passageway exists before said gas generator generates said high temperature and pressure gas, and wherein at least a part of the gas passageway that is made of synthetic resin gradually melts and expands as the high temperature and pressure gas is exhausted.