Patent ID: 6089492
Filing Date: 2000-07-18
Classification: B60R

Abstract:
A pretensioner for a webbing retractor comprising:a winding shaft onto which a webbing is wound;a cylinder into which a fluid is supplied when a vehicle makes a sudden deceleration;a piston which is disposed so as to be able to move inside said cylinder, and which is moved inside said cylinder by the pressure of said fluid so as to rotate said winding shaft in the direction in which said webbing is retracted;a seal holding portion which is formed integrally with the surface of said piston nearest the bottom portion of said cylinder, and which protrudes in the shape of a cylinder;and a sealing member which has elastic properties, which is fitted onto the external periphery of said seal holding portion, which seals the gap between the internal wall of said cylinder and said piston, and which abuts said bottom portion of said cylinder so as to prevent said piston and said bottom portion of said cylinder from coming into contact.