GAS EXHAUST STRUCTURE FOR PRETENSIONER OF SEAR BELT RETRACTOR

摘要

A gas exhaust structure for a pretensioner of a seat belt retractor is provided to seal securely between a cylinder and a piston by attaching a seal member to the piston. A gas exhaust structure for a pretensioner of a seat belt retractor comprises a piston cap(20) having a gas exhaust port. The piston cap is coupled to a lower portion of a coupling section(16) to adjust pressure of gas generated from a gas generator(18). A perforation hole, which is communicated with the gas exhaust port, is formed at an outer portion of the piston cap. A seal member(40) is coupled with the piston cap to seal between a cylinder and the piston cap. The gas generator is disposed below a piston(14) to move the piston.