| 摘要 |
PURPOSE: To provide a lightweight belt tensioner of a vehicular seat belt, which can be manufactured at low cost. CONSTITUTION: In a belt tensioner for a vehicular seat belt retractor, a belt reel of a belt retractor is rotated through a step-up gear by a linear driving device. The driving device is provided with a cylinder tube 42 closed at both ends and having breakage resistance and a hollow piston 44 movable in it. Propellant 50 by explosive technique, having an igniter 52 is housed in the hollow piston. The belt tensioner is a linear driving device capable of safely handled and has a compact shape, the light weight and low manufacturing cost. |
