| 摘要 |
PROBLEM TO BE SOLVED: To efficiently carry out degassing after operation while reducing output loss of a pretensioner unit in the operation.SOLUTION: A retractor 10 for a seat belt includes a take-up drum 30 to be wound with a weaving 12 and a pretensioner unit 40. The pretensioner unit 40 includes a driven body capable of rotating interlocking with the take-up drum 30, a cylinder 42, and a driving body which includes a seal part 43s, is housed in the cylinder 42 to move between an initial position Pa and an ongoing position Pb, and makes the take-up drum 30 rotate for winding through the driven body, and a gas generation part 41 which jets a gas into a gas jet space S of the cylinder 42. The cylinder 42 has a plurality of through-hole parts 42f, 42g, linking the gas jet space S to the outside in a state in which the driving body is at the ongoing position Pb, formed at different position in the length direction of the cylinder 42, at least one of the through-hole parts being formed at a position nearer to a tip side from the seal part 43s of the driving body at the initial position Pa. |
