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 driving element as a pretensioner rod disposed within the tube and a guide plate having a guide portion and a rod guide. The pretensioner rod extends in a longitudinal direction from a proximal end portion to a distal end portion. In addition, the pretensioner rod forms a recessed portion or a recessed section to facilitate engaging with the sprocket during pretensioning.

A power transmission member including a base resin that has a water absorption characteristic that a water absorption rate is 1% or less when Method 1 of ISO 62 (a method for measuring a weight increasing rate after being immersed in water at 23? C. for 24 hours) is used and an elastomer that imparts mechanical characteristics to the power transmission member 32a, in which as the mechanical characteristics, tensile yield stress (ISO 527) is 40 to 54 MPa, tensile fracture strain (ISO 527) is 50% or more, tensile elastic modulus (ISO 527) is 1200 to 1900 MPa, bending elastic modulus (ISO 178) is 1100 to 1700 MPa, and unnotched Charpy impact strength (ISO 179) is no fracture at ?30? C. or higher.

A seatbelt pretensioning retractor assembly for use in a passenger 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 is disposed between the gas generator and the stopper. In another example, the tube has an opening that is adjacent to an exit to facilitate venting gas from the gas generator.

A seatbelt tensioner for a seat belt retractor, having a pipe (1) with a tensioner drive wheel. A pyrotechnical gas generator (10), a piston (3), and at least one mass body (4) in the pipe (1), wherein the at least one mass body (4) is drivable by the pressure generable by the gas generator (10) and acting on the piston (3) between the gas generator (10) and a mass body (4), and which can be made to mesh in a force-transmitting manner with the tensioner drive wheel, thus driving a belt shaft of the seat belt retractor in a belt tensioning direction. The pipe (1) has a receiving section (5) with a first inner diameter (2), in which the piston (3) in its initial state is arranged with an initial-state outer diameter (8) prior to the ignition of the gas generator (10). The pipe (1) has a guide section (6) which adjoins the receiving section (5) and which has a second inner diameter (7). The second inner diameter (7) is smaller than the first inner diameter (2) and smaller than the initial-state outer diameter (8) of the piston (3).

A belt tensioner (10) for a seatbelt system comprises a tensioner tube (20) having an open outlet end and a force transmission element (22) which is guided in the tensioner tube (20) and which leaves the tensioner tube (20) via the open outlet end, a gas generator (18) providing compressed gas for displacing the force transmission element (22) within the tensioner tube (20) as well as a drive wheel (16) rotated by the force transmission element (22) leaving the tensioner tube (20). There is provided a guiding component (24) surrounding the drive wheel (16) into which guiding component the force transmission element (22) enters upon leaving the tensioner tube (20). At the guiding component (24) an energy-dissipating structure (50) is provided which the force transmission element (22) contacts when it has at least substantially completely left the tensioner tube (20).

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).

A seatbelt pretensioning retractor assembly for use in a passenger 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 with a recessed portion. A stopper is coupled to an end portion of the polymer rod. The tube includes a projection extending within the tube adjacent to the exit to define a constriction portion. The constriction portion is sized to permit the recessed portion of the polymer rod to pass therethrough while preventing the stopper from passing therethrough. The polymer rod has a retention feature for releasably engaging the projection.

A webbing take-up device has a pretensioner mechanism that rotates a spool in a take-up direction owing to a micro-gas generator being operated at a time of an emergency of a vehicle. A micro-gas generator mounting portion of the pretensioner mechanism is formed in a shape of a tube into which the micro-gas generator is inserted. The micro-gas generator mounting portion has recessed portions, whose micro-gas generator sides are open, and convex portions that are formed along the recessed portions, and that are formed in shapes that are convex toward the micro-gas generator side, and on which a portion of the micro-gas generator is anchored.

Provided are a pretensioner, a retractor, and a seat belt device in which strength and slidability of a rod-shaped power transmission member may both be achieved. A pretensioner includes a ring gear on which the spool is rotatably disposed, and power transmission units for transmitting power to the ring gear in an emergency. The power transmission units includes a rod-shaped power transmission member for transmitting power to the ring gear while being plastically deformed, a tip reinforcing member disposed on a tip side of the power transmission member, a pipe for containing the power transmission member, and a gas generator disposed at an end of the pipe. The tip reinforcing member has higher strength than the power transmission member.

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.