Abstract: A seatbelt retractor includes a torsion bar (23) which is twisted and deformed depending on a load in a webbing-pull-out direction in case of vehicle collision. One end of the torsion bar is housed in a cylindrical hollow portion which is a hollow extending from an opening provided at an one-end side of a take-up drum (21) to an other-end side thereof co-axially to an axis of rotation, and via a first coupling member (23C), coupled with a concave coupling portion provided on an inner wall surface of the other-end side of the take-up drum with relative rotation of the torsion bar and the take-up drum being disabled.

Abstract: A seat belt retractor includes a take-up drum with webbing wound therearound, a torsion bar coupled to a first end of the take-up drum non-rotatably relative thereto, and a ratchet wheel coupled to a second end of the torsion bar non-rotatably relative thereto. The seat belt retractor further includes a deformable member provided on a second end of the take-up drum for rotating integrally therewith, an internal tooth element (8) provided non-rotatably relative to the torsion bar, and planet gears in mesh with a gear surface of the internal tooth element and in engagement with the deformable member, the planet gears being assembled non-rotatably relative to the torsion bar. The planet gears revolve around the deformable member while biting into the surface of the deformable member to plastically deform the deformable member when the webbing is paid out to cause the sun element and the internal tooth element to rotate relative to each other after an emergency locking member is locked.

Abstract: A seat belt retractor (1) includes a take-up drum (2) with webbing (6) wound therearound, a torsion bar (4) coupled to a first end of the take-up drum (2) non-rotatably relative thereto, and a ratchet wheel (5) coupled to a second end of the torsion bar (4) non-rotatably relative thereto. The seat belt retractor (1) further includes a deformable member (7) provided on a second end of the take-up drum (2) for rotating integrally therewith, an internal tooth element (8) provided non-rotatably relative to the torsion bar (4), and planet gears (13) in mesh with a gear surface of the internal tooth element (8) and in engagement with the deformable member (7), the planet gears (13) being assembled non-rotatably relative to the torsion bar (4).