In a webbing retractor, due to a moving member being moved toward an axial direction distal end side, and first teeth and second teeth of a rotating member piercing the moving member, the rotating member is rotated in a take-up direction. Here, at the moving member, a sectional surface area, in a direction orthogonal to an axis, of a small diameter portion that is at an axial direction distal end side is made to be small as compared with a moving member main body that is at an axial direction proximal end side. Therefore, resistance to movement of the moving member can be reduced.

A seatbelt retractor for a seat belt device in a vehicle. The retractor including a frame and a spool. The spool is configured to be fixed to one end of a webbing which is wound around the spool. A pretensioner device configured to rotate the spool in response to an excessive acceleration of the vehicle. The pretensioner device comprises a power transmission element carried in a pretensioner tube that is driven by a piston located in the pretensioner tube. The pretensioner device includes a gas generator for driving the piston into the power transmission element. The pretensioner device includes a seal system that includes a stopper tube located in a downstream end of the pretensioner tube to create a stop location for the piston to prevent operating gas from exiting the end of the pretensioner tube.

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 rod disposed within the tube and a guide plate having a guide portion and a rod guide. The rod exits the tube along a perimeter of the sprocket, and toward an arcuate landing surface of the guide portion. In addition, the guide plate further includes a couple of tabs and ribs for avoiding rattling of the pretensioner tube in normal use of the retractor assembly.

A seatbelt pretensioning retractor assembly for use in a vehicle is provided. The pretensioning assembly includes a tube in fluid communication with a gas generator and a driving element disposed therein that travels in a first direction in response to actuation of the gas generator. The driving element includes a polymer rod. A stopper is coupled to an end portion of the polymer rod. In one example, a seal member disposed between the gas generator and the stopper includes a head section and a skirt section. In another example, the tube has an opening that is adjacent to an exit to facilitate venting gas from the gas generator.

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 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 rod disposed within the tube and a guide plate having a guide portion and a rod guide. The rod exits the tube along a perimeter of the sprocket, and toward an arcuate landing surface of the guide portion. In addition, the guide plate further includes a couple of tabs and ribs for avoiding rattling of the pretensioner tube in normal use of the retractor assembly.

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.

In a webbing retractor, due to a moving member being moved toward an axial direction distal end side, and first teeth and second teeth of a rotating member piercing the moving member, the rotating member is rotated in a take-up direction. Here, at the moving member, a sectional surface area, in a direction orthogonal to an axis, of a small diameter portion that is at an axial direction distal end side is made to be small as compared with a moving member main body that is at an axial direction proximal end side. Therefore, resistance to movement of the moving member can be reduced.

A webbing take-up device is provided with a spool that takes up a webbing, a lock base, and a cover plate that covers an outer periphery of the lock base. A tooth portion is formed at the outer periphery of the lock base. The lock base rotates the spool when a rack contacts the tooth portion. The webbing take-up device is further provided with a guide provided at the cover plate. The guide supports the lock base to be rotatable. Thus, contacting together of the ratchet teeth and the lock base is restricted.

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.