A webbing take-up device includes a spool that takes up a webbing worn by an occupant, and that is rotated in a pull-out direction due to the webbing being pulled out, and a lock base that limits pull-out direction rotation of the spool in a vehicle emergency. The webbing take-up device further includes an energy absorbing wire that undergoes deformation so as to permit pull-out direction rotation of the spool at or above a force limiter load when the lock base has limited pull-out direction rotation of the spool, and a second force limiter mechanism that adjusts the pressing force of the energy absorbing wire according to a remaining take-up amount of the webbing on the spool.

An increase in structural complexity is suppressed in a webbing take-up device provided with a force limiter load switching mechanism and a pre-tensioner mechanism. The webbing take-up device includes a spool that takes up a webbing, a pre-tensioner mechanism that takes up the webbing onto the spool by rotating the spool in the take-up direction in a vehicle emergency, and a lock mechanism that restricts pull-out direction rotation of the spool in a vehicle emergency. The webbing take-up device further includes a force limiter mechanism that permits pull-out direction rotation of the spool at a force limiter load or greater when the lock mechanism has restricted pull-out direction rotation of the spool, and a force limiter load switching mechanism that switches a force limiter load value by being input with a portion of an actuation force that actuates the pre-tensioner mechanism.

A pretensioner for introducing a webbing wound in a spool by explosive power obtained by exploding gunpowder when an impact is applied from the outside, the pretensioner includes: a hollow cylinder having one side surface for inserting a portion of a pinion connected to the spool; a micro gas generator (MGG) mounted in an upper end portion of the cylinder and for transferring explosive power into the cylinder while gunpowder provided at the inside explodes when an impact is applied from the outside; a rack mounted in a length direction at the inside of the cylinder and having one end portion disposed toward the MGG and having the other end portion disposed opposite to the pinion and having gear teeth provided in one side surface separated not to engage with the pinion before receiving explosive power from the MGG; and a roller for receiving explosive power from the MGG and rotatably mounted at the other side surface opposite to one side surface of the cylinder in which a portion of the pinion is inserted so that the gear teeth of the rack engage with the pinion when the rack falls toward a lower end portion of the cylinder and for guiding the separated rack to move toward the pinion.

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.

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 pretensioner mechanism of a webbing take-up device, a sealing member seals a communicating hole of a piston. When a force limiter mechanism is operated and rotating of a spool in a pull-out direction is allowed, the piston is moved to an upper side in a state in which the sealing member is pressed and contacted against a cylinder. As a result, the sealing member is turned and the sealing of the communicating hole by the sealing member is released. In consequence, a number of components may be reduced and assembly characteristics of the pretensioner mechanism may be improved.

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 seatbelt retractor is provided that can be formed in a smaller size yet properly operated, and capable of smoothly providing seatbelt tension, and a seatbelt assembly including such a seatbelt retractor. The seatbelt retractor includes a frame, a seatbelt, a spool that takes up the seatbelt, the spool being rotatably supported by the frame, a lock mechanism that allows the spool to rotate in a non-activated state and restricts, upon being activated, the spool from rotating in the seatbelt withdrawal direction, and an energy absorption mechanism that limits the load applied to the seatbelt to thereby absorb and alleviate energy of the occupant, and the energy absorption mechanism includes a first torsion bar concentrically enclosed in the spool with one end portion retained by the spool and the other end portion disposed to be locked by the lock mechanism, and disposed to be rotated by torsional force, a second torsion bar eccentrically enclosed in the spool with one end portion 24a disposed to be locked by the lock mechanism, and disposed to be rotated by torsional force, and a moving member that rotates interlocked with the spool, and moves between the first position for retaining the other end portion of the second torsion bar and the second position spaced from the other end portion of the second torsion bar.

The invention relates to a belt retractor for a seatbelt of a motor vehicle, comprising a belt shaft which is rotatably mounted in a housing frame, a profile head which can be locked with respect to the housing frame, a multi-stage first force-limiting device, wherein the first force-limiting device is coupled to the profile head and to the belt shaft, wherein the first force-limiting device allows a force-limited relative rotation of the belt shaft with respect to the locked profile head, and comprising at least one second force-limiting device, wherein, in an initial state, the second force-limiting device is decoupled, so that the force-limited relative rotation of the belt shaft with respect to the locked profile head takes place without a force-limited involvement of the second force-limiting device.

Force absorbing shoulder belt assemblies for vehicle seats, especially aircraft seats, are provided. The shoulder belt assemblies will include a box structure defining an interior space having an open rear end and adapted to being fixed to adjacent vehicle structure, a block of a compressible material positioned within the interior space of the box structure, a rear plate in pressing contact with the rear face of the block of compressible material, and an inertial reel assembly carried by the rear plate and including a shoulder web strap which extends through the rear plate, the block of compressible material and the box structure. When a deceleration force of predetermined magnitude is exerted on the shoulder web strap of the inertial reel, the rear plate will responsively be forcibly pressed against the block of compressible material thereby compressively crushing the compressible material within the box structure to thereby absorb shock force of the shoulder web strap against vehicle seat occupant's torso.