A seat belt retractor including a spool and a measurement mechanism for determining a measure of the amount of seat belt webbing unwound from the spool. The measurement mechanism includes cycloidal gear transmission. A sensor is provided for detecting movement of a magnet mounted on a sensing gear and a controller may be provided for determining a measure indicating the amount of rotation of the spool and the amount of webbing withdrawal based on the movement of the magnet.

A webbing take-up device is provided with a spool, a first rotor and a second rotor. A webbing to be applied to a vehicle occupant is taken up onto the spool by the spool rotating in a take-up direction. The first rotor is provided to be rotatable together with the spool, includes first engaging teeth with which a moving member that is moved engages, and is rotated when the moving member that is moved engages with the first engaging teeth. The second rotor is provided to be rotatable together with the spool, includes second engaging teeth with which the moving member that is moved engages, and is rotated when the moving member that is moved engages with the second engaging teeth. The second engaging teeth are disposed so as to overlap with the first engaging teeth in a rotation circumference direction of the first rotor.

The invention relates, inter alia, to a belt retractor (10) for a safety belt device, with a belt reel (20) for winding up and unwinding the safety belt, a pretensioner drive (40) and a pyrotechnic tensioner drive (30), wherein the pretensioner drive (40) has a force-flux-control element (100) which, in a deactivation position, interrupts the force flux between pretensioner drive (40) and belt reel (20). It is provided that the pyrotechnic tensioner drive (30) has one or more drive elements (33) which, after activation of the pyrotechnic tensioner drive (30), is or are set into motion, and, after activation of the pyrotechnic tensioner drive (30), the force-flux-control element (100) is adjusted directly or indirectly by the drive element (33) orin the case of a plurality of drive elements (33)by at least one of the drive elements (33) of the pyrotechnic tensioner drive (30) into the deactivation position.

Provided are a pretensioner, a retractor, and a seat belt device which can achieve both securing of the strength of a power transmission member in an initial driving stage and reduction of the sliding resistance against the power transmission member in a steady driving stage. The retractor 1 includes a spool 2 for winding up webbing for restraining an occupant and a pretensioner 3 for winding up the webbing in an emergency to remove slack. The pretensioner 3 includes a ring gear 31 connected to the spool 2 and a power transmission device 32 for transmitting power to the ring gear 31 in an emergency. The power transmission device 32 includes a rod-shaped power transmission member 32a which transmits power to the ring gear 31 while being plastically deformed. A tip end of the power transmission member 32a has an enlarged portion 32b formed thicker than other portions of the power transmission member 32a. The enlarged portion 32b is made of the same material as the power transmission member 32a.

A belt tightener for tightening a safety belt in a vehicle includes an impulse screw drive unit to generate a greater torque than can be achieved by a mechanical coupling between a motor and the belt tightener.

A seatbelt pretensioning retractor assembly for use in a vehicle is provided. The seatbelt pretensioning retractor assembly includes a housing adapted for being mounted to a frame and having an interior cavity, a pretensioner tube having an arcuate and curved shape, a sprocket rotatably mounted to the housing and fixedly coupled to a spindle, a polymer rod disposed within the tube and a guide plate having a guide portion and a rod guide. The polymer rod exits the tube along a perimeter of the sprocket, and toward an arcuate landing surface of the guide portion. In addition, the rod guide is configured for preventing the polymer rod from trapping before engaging with the sprocket or after pretensioning.

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.

Provided are a seat belt retractor and a seat belt device capable of stably supplying components and avoiding an increase in cost even when an injection body made of resin is used.

A spool 2 which winds up webbing which restrains an occupant, a base frame 3 which accommodates the spool 2 so as to be rotatable, a spring unit 4 which biases the spool 2 in a winding direction, a pretensioner 5 capable of winding up the webbing in an emergency, and a lock mechanism 6 capable of stopping withdrawal of the webbing are provided, the pretensioner 5 including a rotating body 51 concentrically connected to the spool 2 and an injection body 52a made of resin which rotates the rotating body 51, the rotating body 51 made of metal having a wall thickness T half a diameter D of the injection body 52a or smaller.

In a vehicle emergency, rotation of a lock base in a pull-out direction opposite to a take-up direction is restricted. A first pinion-configuring portion formed at an outer circumferential portion of the lock base configures one width direction side of a pinion section that is rotated in the take-up direction by a rack that moves due to fluid pressure in a vehicle emergency. A coupling member disposed between the lock base and the torsion shaft is fixed to the lock base and to a torsion shaft. A second pinion-configuring portion that configures a width direction other side of the pinion section is formed alongside the first pinion-configuring portion at an outer circumferential portion of the coupling member.

A webbing retractor includes a spool, a motor, a force limiter mechanism, a first rotating body, a second rotating body, a ratchet gear, a pawl body and a control section. The ratchet gear is provided at one of the first rotating body or the second rotating body. The pawl body is provided at another of the first rotating body or the second rotating body. The pawl body can engage with the ratchet gear in a case in which the first rotating body rotates toward one side, and engagement of the pawl body with the ratchet gear being cancelled in a case in which the first rotating body rotates toward another side. The control section drives the motor to rotate in reverse, such that the first rotating body rotates toward another side in a case in which a physical amount relating to load of the passenger exceeds a predetermined value during forward rotational driving.