A belt retractor (40) having a belt reel (14), a seat belt (12) which can be wound thereon to form a belt reel, and at least one first assembly, the first assembly being arranged coaxially with the axis of rotation of the belt reel (14) and in series with the belt reel (14). The belt retractor is especially adapted for mounting inside the frame member of a motor vehicle seat.

A tensioner tube (18) for guiding a load transmission element (20) for a belt tensioner comprises an exit end (32) and a tube section (34) adjacent to the exit end (32), the tube section (34) being configured and arranged so that the longitudinal axis (L) of the tube section (34) is substantially tangent to the drive gear (14), wherein an elongate projection (36) protruding into the interior of the tube, the longitudinal axis (I) of which is inclined in relation to the longitudinal axis (L) of the tube section (34), is formed in the tube section (34) adjacent to the exit end (32). A belt tensioner for a seat belt system comprises a pyrotechnically movable load transmission element (20) and a drive gear (14) which can be driven by the movable load transmission element (20). The load transmission element (20) is guided in a tensioner tube (18) of the above-mentioned type.

In a webbing take-up device, a moving member is moved while being guided along a cylinder in order to rotate a spool in a take-up direction. A urging plate of a guide member urges a flange at an axial direction leading end portion of the cylinder toward a restricting direction side, and a leg plate of a frame restricts rotation of the flange toward the restricting direction side. This enables rattling of the axial direction leading end portion of the cylinder about the axial direction of the cylinder to be suppressed.

A seatbelt pretensioner system for use in a seatbelt retractor assembly having a spindle and a frame includes a housing adapted for being mounted to the frame and having an interior cavity, a pretensioner tube including a body portion and an exit portion, and having a first tube end in fluid communication with a gas generator and a second tube end in fluid communication with the interior cavity of the housing, a pinion being rotatably mounted in the housing and fixedly coupled to the spindle adapted for taking up seatbelt webbing during pretensioning, a pretensioner rod disposed inside the pretensioner tube, and a stopper disposed between the gas generator and the pretensioner rod. Further, the exit portion of the tube is formed to neck down such that the exit portion is configured to prevent the stopper from passing therethrough.

A seatbelt pretensioner system for use in a seatbelt retractor assembly having a spindle and a frame includes a housing adapted for being mounted to the frame and having an interior cavity, a pretensioner tube having a first tube end in fluid communication with a gas generator and a second tube end in fluid communication with the interior cavity of the housing, a pinion being rotatably mounted in the housing and fixedly coupled to the spindle adapted for taking up seatbelt webbing during pretensioning, and a pretensioner rod disposed inside the pretensioner tube. Further, the pretensioner rod has a proximal end disposed towards the gas generator and a distal end disposed away from the gas generator. In addition, the housing is formed with at least two levels including an inboard portion and an outboard portion to store the pretensioner rod after pretensioning.

A seatbelt pretensioner system for use in a seatbelt retractor assembly having a spindle includes a frame assembly having a frame and an attachment bracket adapted to be interlocked to have an inner space for receiving the spindle, a housing adapted for being mounted to the frame and having an interior cavity, a pretensioner tube having a first tube end in fluid communication with a gas generator and a second tube end in fluid communication with the interior cavity of the housing, a pinion being rotatably mounted in the housing and fixedly coupled to the spindle adapted for taking up seatbelt webbing during pretensioning, and a pretensioner rod disposed inside the pretensioner tube. Further, the pretensioner rod has a proximal end disposed towards the gas generator and a distal end disposed away from the gas generator.

A belt retractor having a belt shaft having a shaft body, a profile head and a torsion bar, wherein the torsion bar arranged in the shaft body is connected on one end to the shaft body and on a second end to the profile head, and the profile head can be securely attached to the vehicle, and having a belt pretensioner, wherein a pretensioner drive wheel of the belt pretensioner is directly connected in a rotationally fixed manner to the profile head of the belt shaft, and mass bodies can be engaged with the pretensioner drive wheel so as to transmit force to drive the belt shaft in winding direction. The pretensioner drive wheel (16) is configured by means of two parts, the profile head (1) of the belt shaft and a push-on ring (2) that is pushed onto the profile head (1) and is positively and non-positively connected thereto, wherein respectively mutually opposite dome-shaped partial receiving socket segments (3), which form together receiving sockets for the mass bodies, are formed on the profile head (1) and on the push-on ring (2).

Provided are a pretensioner, a retractor, and a seat belt device that can effectively reduce kinetic energy of an injected power transmission member. A power transmission unit includes a power transmission member that is engageable with external teeth of the ring gear, a pipe that contains the power transmission member, a gas generator that is disposed at an end of the pipe, a piston that receives gas generated from the gas generator to press the power transmission member, a first stopper that is disposed on an upstream side of the power transmission member, a second stopper that is disposed between the power transmission member and the piston, and a pretensioner cover that defines a passage for the power transmission member.

A belt retractor (10) for a seat belt comprising a belt reel (20), a belt tensioner (44) adapted to drive the belt reel (20) in a winding direction and an extension limiter (16) adapted to restrict the number of revolutions of the belt reel (20) in an unwinding direction in the activated state. The extension limiter (16) is communicated with the belt tensioner (44) so that the extension limiter (16) can only be activated after the belt tensioner (44) has been activated.

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.