A pretensioner includes a drive wheel provided with a plurality of engaging teeth for rotating a spool, the spool for winding up a webbing for fastening a passenger; and an elongated resin component that transmits power to the drive wheel during an emergency, wherein the plurality of teeth is positioned such that, when one engaging tooth is caused to contact a tip of the elongated resin component in an approximately planer manner, another engaging tooth adjacent to the one engaging tooth in a direction opposite to a rotation direction can contact a side surface of the elongated resin component.

A pretensioner includes a driving wheel and a power transmission unit. A spool is rotatably disposed in the driving wheel. The spool winds a webbing. The power transmission unit transmits power to the driving wheel. The power transmission unit includes a resin-made long body and a passage of the resin-made long body. The resin-made long body rotates the driving wheel. The passage is formed in an outer circumference of the driving wheel. The passage includes a wall surface, a cover member and a stopper. The wall surface is disposed on one side surface of the driving wheel. The cover member is fixed in the wall surface from the other side surface of the driving wheel. The stopper stops a tip portion of the resin-made long body which has rotated the driving wheel. The stopper is configured by a fastening member connecting the cover member and the wall surface.

An increase in structural complexity is suppressed in a webbing take-up device provided with a force limiter load switching mechanism and a pre-tensioner mechanism. The webbing take-up device includes a spool that takes up a webbing, a pre-tensioner mechanism that takes up the webbing onto the spool by rotating the spool in the take-up direction in a vehicle emergency, and a lock mechanism that restricts pull-out direction rotation of the spool in a vehicle emergency. The webbing take-up device further includes a force limiter mechanism that permits pull-out direction rotation of the spool at a force limiter load or greater when the lock mechanism has restricted pull-out direction rotation of the spool, and a force limiter load switching mechanism that switches a force limiter load value by being input with a portion of an actuation force that actuates the pre-tensioner mechanism.

A seatbelt retractor includes a base, a spool, a cylinder, a transfer plate, and a cylinder lock. The spool is rotatably coupled to the base and has a piston portion. The cylinder is engaged with the piston portion and therewith defines a chamber. The piston portion is movable from a first position to a second position. The transfer plate is translateably disposed in the first chamber. The cylinder lock in a first condition rotatably fixes the cylinder to the base. Damping fluid is in the chamber.

A seat belt system for protecting an occupant of a vehicle, the system having seat belt webbing connected to a seat belt retractor that includes (a) a frame; (b) a spool with the seat belt webbing wound around, wherein the spool is rotatably mounted to the frame and configured to rotate in a webbing extraction direction and a webbing retraction direction; (c) an energy absorbing device for absorbing energy when the spool is rotated in the webbing extraction direction after an emergency event has occurred; and (d) a mechanism for selectively cancelling the operation of the energy absorbing device by preventing motion of the spool in the webbing extraction direction.

A seatbelt retractor includes a base, a spool, a cylinder, a sleeve and a cylinder lock. The spool is rotatably coupled to the base and has a piston portion. A smaller initialization piston extends from the piston portion. The cylinder is engaged with the piston portion and therewith defines a first chamber. The sleeve is within the cylinder and receives the initialization piston. The sleeve and the initialization piston define an initialization chamber. The cylinder lock in a first condition rotatably fixes the cylinder to the base. Damping fluid is disposed in the chamber.

Provided is a webbing take-up device including (i) a spool onto which webbing worn by an occupant is taken up as a result of the spool being rotated in a take-up direction, (ii) a rotating body that is provided so as to be integrally rotatable with the spool, has plural teeth disposed an interval apart from each other along a circumferential direction of rotation of the spool, and is rotated as a result of a moving member being moved and becoming engaged with the plural teeth so that the spool is rotated in the take-up direction, and (iii) a regulating portion that opposes the plural teeth in an axial direction of rotation of the spool, is provided so as to be integrally rotatable with the rotating body, and regulates movement, in a direction away from the plural teeth, of the moving member engaged with the plural teeth.

A webbing take-up device is provided with (i) a spool and (ii) a rotor rotatable integrally with the spool having a base portion and radially-extending engaging teeth. A webbing to be applied to a vehicle occupant is wound around the spool. Each engaging tooth protrudes from the base portion in a rotation axis direction of the spool, and is tapered along the rotation axis direction such that a thickness dimension in a rotation circumference direction of the spool of a portion of the engaging tooth at the opposite side thereof from the base portion becomes smaller toward the base portion side thereof. The axially-tapered shape of the engaging teeth reduces stresses and improves transmission efficiency between the rotor teeth and the teeth of a moving member engaged thereto.

A seatbelt device for a vehicle comprises a belt which restrains an occupant, a retractor which supports the belt so as to wind up one end of the belt, a frictional-force applier which is configured to apply a frictional force to the belt by contacting the belt, and an actuator to actuate the frictional-force applier so as to change the frictional force.

A pretensioner and safety belt assembly may include includes a base member fixed to a vehicle, a torsion shaft having a first side and a second side rotatably supported on the base member, a torsion tube having a first end portion fixed on an external surface of the torsion shaft and a second end portion rotatably supported on the external surface of the torsion shaft wherein a belt configured to restrain an occupant is wound around an external surface of the torsion tube, a traction wire wound around an end portion of the torsion shaft on an opposite side to where the torsion tube is fixed to the torsion shaft in an opposite direction to a direction in which the belt is wound, and a pulling device configured to pull the traction wire to rotate the torsion shaft.