A switching mechanism (100) in a force limiter mechanism of a seat belt retractor including: a locking mechanism including a locking element (68) that locks a torque tube (64) with respect to a spindle (61) so that the torque tube (64) rotates together with the spindle (61) and a spindle ring (70); a switch ring (120) rotatable to unlock the locking mechanism; and a switch housing (101) that stores the switch ring (120), a switch piston (115) adapted to activate the switch ring (120). A switching gas generator (116) generates gas for pushing out the switch piston (115) upon activation of the switching mechanism. The switch housing (101) of the switching mechanism (100) has a protrusion (110) that protrudes in an incoming direction of an operated part (122) at an abutment part hit by the switch ring (120) rotated by the switch piston (115) to control movement of the switch ring.

Provided are a seat belt retractor and a seat belt device with which it is possible to improve energy absorption characteristics and a restraining property. The seat belt retractor includes a spool that performs winding of a webbing for restraining an occupant, a shaft inserted through an axial center of the spool, and a locking base connected to the shaft and capable of switching between a rotating state and a non-rotating state. The seat belt retractor further includes a load adjustment member disposed between the shaft and the locking base and that blocks or reduces load transmission in a case where a load equal to or greater than a threshold is applied to the shaft, and an energy absorption device disposed between the spool and the locking base and capable of changing an energy absorption amount according to a relative rotation speed between the spool and the locking base. The energy absorption device is connected in parallel with the load adjustment member.

In a webbing take-up device, a first rotation section and a second rotation section are coupled by forming a first detachment prevention portion at a vehicle rear side end portion of a circular cylinder portion of the second rotation section. Moreover, a mounting portion of a torsion bar is inserted inside the vehicle rear side end portion of the circular cylinder portion in this state. This enables deformation of the vehicle rear side end portion of the circular cylinder portion to be suppressed, and enables deformation of the first detachment prevention portion to be suppressed.

A seatbelt retractor for a seat belt device in a vehicle. The retractor includes a frame and a spool configured to be fixed to one end of a seat belt webbing so that the webbing may be wound around the spool. The spool is rotatably mounted at both ends to the frame and configured to rotate in a webbing extraction direction and a webbing retraction direction. The retractor includes primary and secondary torsion bars positioned end to end in the spool along an axis of rotation of the spool. The primary and secondary torsion bars are configured to be locked at second ends of the torsion bars opposite to the first end. The first ends of the torsion bars are configured to rotate relative to the second ends so that the primary and secondary torsion bars deform to absorb force when a vehicle acceleration exceeds a predetermined value.

A seat belt retractor includes a housing including a pair of side walls facing each other, a winding drum configured to wind up a webbing, a locking base prevented from being rotated in the pull-out direction, in an emergency of a vehicle, an impact energy absorbing member including a first end side coupled to the winding drum and a second end side coupled to the locking base, the impact energy absorbing member connecting the winding drum and the locking base so as to be integrally rotatable, in a normal state, at least one impact energy absorbing wire housed in at least one slot that is provided in the winding drum, and a stopper member configured to define an allowable amount of relative rotation between the winding drum and the locking base in a case where the impact energy absorbing member absorbs the impact energy.

A seat belt retractor includes a housing including a first side wall and a second side wall facing each other, a winding drum configured to wind up a webbing, a locking base, a torsion bar including one end side, which is opposite to the locking base, coupled to the winding drum without being rotatable relative to the winding drum, and the other end side coupled to the locking base without being rotatable relative to the locking base, a pretensioner including: a pretensioner casing attached to the first side wall; and a drive wheel attached to the locking base, a lock member located in the locking base, and a stopper member being screwed onto a male screw of the locking base.

A belt retractor for a safety belt, having a belt reel for winding or unwinding the safety belt, and a belt force limiting installation which comprises a first and second torsion bar for limiting belt force. The belt retractor has a free-wheeling transmission which operates depending on the rotation angle and which after activation of the belt force limiting installation initially leaves the second torsion bar so as to be inactive, while the first torsion bar for limiting belt force is already being twisted, and the free-wheeling transmission activates the second torsion bar as soon as the free-wheeling transmission has been rotated about a predefined maximum free-wheeling rotation angle.

[Object] To provide a seat belt retractor that is capable of generating a more stable load when restricting a load acting on the seat belt and when absorbing energy, and a seat belt apparatus including the same. [Solution] A seat belt retractor 3 includes a frame 11, a seat belt 4, a spool 12 that is rotatably supported by the frame 11 and that retracts the seat belt 4, a lock mechanism 60 that allows rotation of the spool 12 while not in operation and that prevents rotation of the spool 12 in a seat belt withdrawing direction while in operation, and an energy absorption mechanism 20 that restricts a load acting on the seat belt 4 and that absorbs energy of an occupant. In the seat belt retractor 3, the energy absorption mechanism 20 includes a first energy absorption member 21 that absorbs energy through a rotational difference between the spool 12 and the lock mechanism 60, a first energy transmission member 22 that is attached on one end side of the first energy absorption member 21, a second energy transmission member 23 that meshes with the first energy transmission member 22, and a second energy absorption member 24 that absorbs energy through a rotational difference between the second energy transmission member 23 and the spool 12.

A seat belt retractor includes a housing including a pair of side walls facing each other, a winding drum configured to wind up a webbing, a locking base being prevented from being rotated in the pull-out direction, in an emergency of a vehicle, an impact energy absorbing member connecting the winding drum and the locking base so as to be integrally rotatable in a normal state, an impact energy absorbing wire housed in a slot provided in the winding drum so as to form an opening in the first end surface of the winding drum, a ring provided integrally with or separately from the locking base, and a stopper member being configured to define an allowable amount of relative rotation between the winding drum and the locking base in a case where the impact energy absorbing member absorbs the impact energy.

A seat belt retractor includes a housing including a pair of side walls facing each other, a winding drum configured to wind up a webbing, a locking base prevented from being rotated in the pull-out direction, in an emergency of a vehicle, an impact energy absorbing member including a first end side coupled to the winding drum and a second end side coupled to the locking base, the impact energy absorbing member connecting the winding drum and the locking base so as to be integrally rotatable, in a normal state, at least one impact energy absorbing wire housed in at least one slot that is provided in the winding drum, and a stopper member configured to define an allowable amount of relative rotation between the winding drum and the locking base in a case where the impact energy absorbing member absorbs the impact energy.