In a seat belt retractor (12) for a vehicle, comprising a frame (14) in which a belt reel (10) is supported which includes a reel body (26) as wed as a first flange (32) and a second flange (34), said flanges being provided at the axial ends (28, 30) of the reel body (26) and each being arranged in a seat (22) of the frame (14), wherein the first flange (32) is rotatable relative to the reel body (26) and wherein between the first flange (32) and the reel body (26) a force limiter is provided, and at the seat (22) locking teeth (24) are provided and at the first flange (32) a toothing corresponding to the locking teeth is provided, the second flange (34) is rotatable relative to the reel body (26) and at the second flange (34) and/or at the reel body (26) interacting stops (50, 54, 58) are provided for limiting rotation of the second flange (34) relative to the reel body (26). Furthermore, the second flange (34) Includes a peripheral wall (44) which encloses the axial end (30) of the reel body (26) facing the second flange (34) in the peripheral direction.

A fluid damper for modulating a retaining force of a seat belt is provided. The fluid damper includes an outer cylinder and an inner cylinder. The inner cylinder encloses an inner space. The fluid damper includes a piston shiftable in the inner space. The fluid damper includes a duct. The duct conductively connects a front fluid chamber disposed in front of the piston to a rear fluid chamber disposed behind the piston and/or a reservoir for the damping fluid. The duct includes an outer duct portion and an inner duct portion. The inner cylinder is deflectable from a rest position by a force acting on the piston so that the deflection of the inner cylinder causes an adjustment of an overlap of the outer duct portion and the inner duct portion depending on the magnitude of the force.

A webbing take-up device includes: a spool that enables pull-out and take-up of a webbing; a rotor disposed opposite from the spool, rotation of the rotor being impeded at a time of emergency; a wire of which a proximal end portion is retained at the rotor, at least a distal end portion of the wire being retained at the spool, the wire being disposed between the rotor and the spool, wherein the webbing is pulled out at a time of emergency of a vehicle, the wire being deformed and being wound onto a winding portion of the spool; and a retreat portion provided at the winding portion, the distal end portion of the wire being disposed at the retreat portion in a case in which the wire is wound onto the winding portion.

A retractor includes a spool, a torsion bar and a torsion tube rotationally fixed to the spool, and a locking member aligned with the torsion bar. The torsion bar and the torsion tube extend coaxially from the spool to respective first ends, and the torsion bar has a key. The locking member is movable from an unlocked position rotationally disengaged with the torsion bar to a locked position wherein the key rotationally fixes the locking member to the first end of the torsion bar. When the locking member is in the unlocked position, the torsion bar may be plastically deformed to limit the load applied by webbing against an occupant. If sufficient force is applied to the webbing, the locking member moves to the locked position in which both torsion bar and the torsion tube are locked together and, in tandem, limit the load applied by the webbing.

Provided is a pretensioner that can be easily and accurately assembled and manufactured, a seat belt retractor, and a seat belt apparatus provided with the seat belt retractor. A pretensioner has at least a gas generator for generating gas in the event of an emergency, a case, a pipe mounted to the case, a predetermined number of drive transmission members that are movably provided in the pipe and moved by receiving gas pressure to transmit force for rotating the spool in the seat-belt retracting direction, a piston that is movably provided in the pipe and moved by receiving gas pressure to push the drive transmission members, a ring gear that is at least rotatably provided in the case, has, on the outer periphery thereof, a plurality of pressed portions pressed by the drive transmission members, and rotates the spool by the pressing force, and an elastic member attached to the gas generator side of the piston.

In a webbing take-up device, in a state in which a stopper of a force limiter stopper mechanism has been brought into abutting contact with a stopper abutment portion resulting in rotation of a spool in a pull-out direction having become limited, the stopper is disposed on the inside of a flywheel hole portion of a flywheel body of a flywheel of a second force limiter mechanism. For this reason, deformation of the stopper outward in its radial direction can be suppressed by the flywheel body of the flywheel.

Provided are a seat belt retractor and a seat belt device with which it is possible to improve an occupant-restraining property and energy absorption characteristics. A seat belt retractor 1 including a spool 2 that winds up a webbing W for restraining an occupant, a shaft 3 inserted through an axial center of the spool 2, and a locking base 4 connected to the shaft 3 and capable of switching between a rotating state and a non-rotating state, further includes an energy absorption device 5 capable of changing an energy absorption amount according to a relative rotation speed between the spool 2 and the shaft 3, and a load adjustment member 6 that blocks or reduces load transmission when a load equal to or greater than a threshold is applied to the shaft 3 or the spool 2. The spool 2, the shaft 3, the locking base 4, the energy absorption device 5, and the load adjustment member 6 are serially connected.

A seat belt retractor that has a simple structure, easy to manufacture and operates accurately is provided, and a seat belt apparatus provided with the seat belt retractor is also provided. The seat belt retractor includes energy absorbing mechanisms that absorb and alleviate the energy of a vehicle occupant by limiting a load applied to a seat belt. The energy absorbing mechanisms is coaxially incorporated in a spool, whose one end portion is retained by the spool and the other end can be locked by the lock mechanism, and obtains a rotational force when being twisted. The second energy absorbing mechanism includes a first rotating member rotatable together with the spool, an abutting member relatively rotatable with respect to the first rotating member by a predetermined angle, a second rotating member relatively rotatable with respect to the abutting member, and an energy absorbing member whose one end portion is fixed to and supported by the second rotating member and the other end portion abuts against the abutting member.

A webbing take-up device in which, when a pretensioner mechanism is activated and turning of a pinion relative to a spool is allowed, a lock pawl is turned by the pinion and a trigger wire is sheared by the lock pawl. Thereafter, the pinion turns more relative to the lock pawl and shears a lock pin of the lock pawl. Hence, the lock pawl turns and activates an activation mechanism. Therefore, the activation mechanism may be activated without a torsion shaft of a force limiter mechanism allowing turning of a lock base in the take-up direction relative to the spool.

A switching mechanism (100) in a force limiter mechanism of a seat belt retractor including: a locking mechanism including a locking element (68) that locks a torque tube (64) with respect to a spindle (61) so that the torque tube (64) rotates together with the spindle (61) and a spindle ring (70); a switch ring (120) rotatable to unlock the locking mechanism; and a switch housing (101) that stores the switch ring (120), a switch piston (115) adapted to activate the switch ring (120). A switching gas generator (116) generates gas for pushing out the switch piston (115) upon activation of the switching mechanism. The switch housing (101) of the switching mechanism (100) has a protrusion (110) that protrudes in an incoming direction of an operated part (122) at an abutment part hit by the switch ring (120) rotated by the switch piston (115) to control movement of the switch ring.