A seatbelt pretensioner is provided including an inner tube with a gas generator housed therein, an intermediate sleeve extending over the inner tube, and a spool portion housing the sleeve and the tube. The spool portion includes spiraling flutes thereon that correspond to a protruding member in the form of flutes or pegs extending from the intermediate sleeve. In response to the gas generator firing, the sleeve will be driven longitudinally, causing the protruding member to act on the spiraling flutes of the spool, thereby causing the spool to rotate. The intermediate sleeve can include a spiraling slot that receives a peg from the inner tube, so that the intermediate sleeve will rotate to compound the spool rotation.

In a coupling (18) for a belt tensioner (10) in a vehicle comprising an input element (26), an output element (34), a coupling element (28) which is movably supported between an initial position and an activated position and in the activated position couples the input element (26) to the output element (34), and a control element (36) which upon movement of the input element (26) relative to the control element (36) moves the coupling element (28) between the initial position and the activated position, the control element (36) is coupled to an inertia mass (36).

A webbing take-up device is obtained capable of restricting movement of a clutch member in the axial direction of a second gear. In the webbing take-up device, a movement prevention portion is formed, on a rotor side, at an intermediate bottom portion of a large gear portion, and a clutch spring attached to the rotor abuts the movement prevention portion, thereby preventing any movement of the clutch spring further to the intermediate bottom portion side. Movement of the clutch spring in the axial direction of the rotor can accordingly be suppressed, enabling movement of the clutch spring in the axial direction of the rotor to be restricted.

A pretensioner having a fracture connection-type rack gear includes: a housing having a receiving space; a pinion gear provided in the receiving space, connected to a rotating shaft of a spool around which a webbing of a seat belt is wound, and rotated by rotation of the spool; a micro gas generator generating explosive power by impact from the outside; a conveying pipe having one side connected with the micro gas generator and the other side having an opening and connected to the receiving space; ball members provided in the conveying pipe, and conveyed toward the receiving space by the explosive power; and a rack gear provided to be fixed into the receiving space by a fixing unit, meshing with the pinion gear when the fixing unit is fractured, and rotating the pinion gear, by residual thrust of the ball members, in a direction in which the webbing is retracted.

The invention relates to a belt tensioner (10) for a seat belt system comprising a belt shaft housing (18) and a belt shaft (12) pivoted in the belt shaft housing (18) about an axis (A), wherein prior to activation of the belt tensioner (10) the belt shaft (12) is retained in a torsionally fixed manner relative to the belt shaft housing (18) in at least one direction of rotation.

A webbing take-up device is obtained capable of suppressing slight axial direction movement of a gear configuring a mechanism to release overload. A large gear portion of a two-step gear configuring an overload release mechanism of the webbing take-up device is sandwiched between a small gear portion end face of a small gear portion and a bottom portion of a rotor. This thereby enables rattling which is slight axial direction movement of the large gear portion to be suppressed.

A controllable clutch (18) for a belt tensioner (16) comprises a drive member (32), a driven element (24) and a clutch pawl (40) that is movably supported on the input side (30) between a home position and an engaged position and in the engaged position couples the drive member (32) to the driven element (24), wherein the clutch pawl (40) is tension-loaded in the engaged position.

An end fitting tensioner (10) for a seat belt system includes a rotatable belt shaft (12) to which one end (14) of a webbing (16) is fixed, a belt shaft housing (18) in which the belt shaft (12) is supported, a rope reel (36) which is arranged at an axial end of the belt shaft (12) and is connected to the belt shaft (12) in a rotationally fixed manner, as well as a pull rope (41) which is secured by one rope end (45) on the rope reel (36) and can at least partly be wound onto the rope reel (36). The rope reel (36) includes a winding surface (62) for the pull rope (41) that is conically tapered in the axial direction.

An adaptive load-limiting seatbelt assembly for a passenger vehicle includes a rotatable spool drum storing a length of seatbelt webbing and a piezoelectric device defining an interference fit between a pair of members of the piezoelectric device. The spool drum is operatively disconnected from the piezoelectric device during normal operation of the seatbelt assembly to permit free rotation of the spool drum and is operatively connected to the piezoelectric device during a dynamic event such as a vehicle crash so that the interference fit resists rotation of the spool drum in the pay-out direction to dynamically or statically control pay-out of the seatbelt webbing during the dynamic event.

A seat belt device includes a spindle (11) for retracting a seat belt (13), an electric actuator (55), a pre-tensioner (14) and a power transmission mechanism (20), wherein the power transmission mechanism (20) can reversibly switch the connection and disconnection between the electric actuator (55) and the spindle (11) before the pre-tensioner (14) is activated, while when the pre-tensioner (14) is activated. The power transmission mechanism (20) non-reversibly interrupts the connection between the electric actuator (55) and the spindle (11) via an elastic piece (60) when a torque difference between an actuator-side gear (80) and a spindle-side gear (82) becomes larger than a predetermined value.