| 摘要 |
PROBLEM TO BE SOLVED: To provide the retractor for a seat belt with a pretensioner providing a favorable clutch mechanism which can be combined with an energy absorption mechanism easily. SOLUTION: The clutch mechanism 30 of a pretensioner is provided with a sleeve 14 arranged on the shaft part 4 of a bobbin, a cam surface 12b in which a clutch rotor 12 supported relatively and rotatably around an axial center constitutes a nearly wedge shape space between a sleeve outer periphery surface and a roller pin 10 arranged in the wedge shape space and movable in a sleeve engaging direction. When the shaft part 4 is rotated in a webbing extension direction, an one way clutch means 70 for obstructing the rotation in the webbing extension direction of a clutch plate 45 for a base side wall 11a through a clutch ring 46 obstructs the rotation of a roller pin 10 rotating in the webbing extension direction along with the shaft part 4 and releases the engagement of the clutch rotor 12 with the sleeve 14 and makes a clutch mechanism 30 in a non-connection state. |
