Pretensioner

摘要

An improved pretensioner which achieves more stable operation and reduction in power loss. The pretensioner includes a gas generator, a pipe containing a plurality of balls and a piston, and a clutch for connecting the pretensioner to a spool for a seat belt. A gas release hole is formed in the pipe in such a position that before the piston moves the hole is between the piston and the first ball and when the coupling of the clutch is completed by the movement of the accelerated balls and the hole is located between the gas generator and the piston.