A reinforced spool assembly has a shaft, a spool member coaxially mounted around the shaft, and two ratchets mounted on two axial ends of a combination of the shaft and the spool member. Each one of two ratchets has a body having an inner surface. The two inner surfaces of the two bodies face each other. In each one of the ratchets, the body has a reinforced supporting structure. The reinforced supporting structure is located between the shaft and the spool member and is offset from the inner surface of the body. A reference plane is defined on and extends along the inner surface of the body, is perpendicular to a central axis of the shaft, and passes through the reinforced supporting structure. Mechanical strength of the reinforced spool assembly is increased by the reinforced supporting structure.

A webbing take-up device includes a spool on which a webbing worn by an occupant is taken up, and a motor that includes a rotor with a rotation shaft and a motor housing covering part of the rotor, the rotor being urged toward one axial direction side of the rotation shaft with respect to the motor housing. The webbing take-up device further includes a second transmission mechanism that includes an A-gear fixed to the rotation shaft, and a B-gear meshed together with the A-gear and rotated by the A-gear being rotated toward one side together with the rotation shaft such that the spool is rotated. A helix angle of respective outer teeth of the A-gear is set such that an axial direction force toward the one axial direction side of the rotation shaft acts on the A-gear when the rotation shaft is rotated toward the one side.

A webbing take-up device includes a spool on which a webbing worn by an occupant is taken up, and a motor that includes a rotation shaft and a first boss portion disposed coaxially with the rotation shaft. The webbing take-up device further includes an A-gear that is fixed to the rotation shaft, and a B-gear that meshes together with the A-gear and that is rotated by the A-gear being rotated such that the spool is rotated. The webbing take-up device further includes a gear housing that includes a B-gear support portion on which the B-gear is supported, and an engaged hole engaged by the first boss portion so as to have tightening margin therebetween, and to which the motor is fixed in a state in which the first boss portion has engaged with the engaged hole.

The present invention relates to a belt retractor comprising a belt shaft, which is mounted rotatably in a frame and on which a safety belt can be wound, and a force-limiting unit which, when activated, enables a rotational movement of the belt shaft in the extension direction of the safety belt, wherein the force-limiting unit comprises an electric motor and a first blocking device, and the first blocking device is configured to release and again block, in a manner actuated by the activation of the electric motor, a rotational movement of the belt shaft in the extension direction in a repeating sequence.

An engagement and disengagement device used in a seat belt retractor includes a first rotating member and a second rotating member configured to be coaxial, and a transmission member disposed between the first and second rotating members. The first rotating member defines an engagement portion on a radial inner surface thereof, and the distance from the engagement portion to an axis of rotation gradually increases in a first direction of rotation. The transmission member can rotate between an engagement position and a non-engagement position relative to the first rotating member.

An engagement and disengagement device used in a seat belt retractor including a first rotating member capable of being driven to rotate about a rotation axis thereof, a second rotating member provided coaxially with the first rotating member and connected to a reel of the seat belt retractor in an anti-torsion manner, and a transmission member provided between the first and second rotating member. The first rotating member is capable of transmitting torque to the second rotating member by means of the transmission member. The transmission member includes a holder and a transmission element in the holder. A first elastic component elastically holds the transmission element by radially exerting a force that enables the transmission element to be located away from the first or the second rotating member, and the first elastic component is integrated on the holder.

A subassembly includes a belt reel for a seat belt retractor and a drive wheel on which a belt tensioner can act to drive the belt reel in a winding direction of the seat belt, wherein between the drive wheel and the belt reel there is provided an overload clutch which includes plural shear elements, especially shear pins, each of which is inserted in an opening of the belt reel and/or of the drive wheel, the opening extending in the axial direction starting from a front side of the belt reel.

In a webbing take-up device, an angle from one end portion toward another end portion of a second clutch spring in a direction of winding of a coil portion from the one end portion toward the another end portion of the second clutch spring is 270°. Therefore, in a case in which the one end portion of the second clutch spring is rotated toward a side of the direction of the winding of the coil portion, one end side portion of the second clutch spring is displaced so as to bulge-out toward a side opposite to a side toward which another end side portion bulges-out.

A webbing take-up device including: a spool; a rotating member configured such that the spool is rotated in a take-up direction by the rotating member being rotated toward one side; a cylinder open at an axial direction leading end side; a fluid supplier provided at an axial direction base end side of the cylinder and supplying a fluid inside the cylinder in a vehicle emergency; a moving member provided inside the cylinder, moved toward the axial direction leading end side of the cylinder due to pressure of the fluid, and rotating the rotating member toward the one side by being moved in a state in which a tooth of the rotating member has bitten into or pierced the moving member; and a stopper provided further toward a movement direction side of the moving member than a section where the tooth of the rotating member has bitten into or pierced the moving member, the stopper being pressed by a portion of the moving member where the biting into or piercing of the rotating member has been disengaged, the stopper being engaged by teeth of the rotating member, and the stopper suppresses rotation of the rotating member toward the one side by the stopper being moved toward the section where teeth of the rotating member bite into or pierce the moving member.

A seatbelt retractor that includes a locking mechanism to prevent rotation of a spool in an extracting direction, a ratchet gear 7 and a locking gear 30 that integrally rotate with the spool, a clutch 50 that moves a pawl 9 from a rest position to an engaging position with respect to the ratchet gear 7, a clutch biasing member that biases the clutch 50 in a retracting direction and in a extracting direction, and a connecting mechanism to connect the clutch 50 to the locking gear 30. When extraction of the webbing is locked, a direction of biasing to rotate of the clutch 50 is maintained in the extracting direction so that the amount of retraction of the webbing required to release the lock is reduced to achieve quick release of the lock.