Patent ID: 7624940

Claim:
A webbing retractor comprising: a take-up shaft rotatably mounted between two sides of said retractor around which a webbing for restraining a vehicle occupant is wound so as to be able to be taken-up thereon and pulled-out therefrom; an acceleration detecting mechanism provided at one of said sides of the retractor, and detecting a moving acceleration of the webbing retractor and/or a pull-out acceleration of the webbing, and causing a lock member to engage with the take-up shaft on the basis of results of said detection; a pretensioner mechanism provided on the same one of said sides of the retractor and in a vicinity of the acceleration detecting mechanism, and having a piston disposed within a cylinder and movable along an axis by gas pressure toward an open end of the cylinder and rotating the take-up shaft in a take-up direction, wherein exhaust gases of said pretensioner mechanism are blown out of said open end of said cylinder; a cover plate housing said pretensioner mechanism, and a blocking wall provided between said open end of said cylinder and the acceleration detecting mechanism that directs exhausted gas blown out of said open end of said cylinder away from the acceleration detecting mechanism, wherein said cover plate has an open portion at a lower side thereof that is attached to one of said sides of said retractor, said pretensioner mechanism is accommodated between said one of said sides of said retractor and said cover plate, said blocking wall is positioned at the open portion of said cover plate, and the open portion of said cover plate is closed by said blocking wall except for a portion corresponding to said open end of the cylinder such that exhaust gas blown out from the open end of the cylinder is directed away from the acceleration detecting mechanism.