A seatbelt pretensioner assembly includes a body. The seatbelt pretensioner assembly includes a shaft rotatably supported by the body. The seatbelt pretensioner assembly includes a spring operatively engaged between the body and the shaft. The seatbelt pretensioner assembly includes a solenoid supported by the body and movable between a first position inhibiting rotation of the shaft relative to the body and a second position permitting rotation of the shaft relative to the body.

A seatbelt pretensioner assembly includes a body. The seatbelt pretensioner assembly includes a shaft rotatably supported by the body. The seatbelt pretensioner assembly includes a spring operatively engaged between the body and the shaft. The seatbelt pretensioner assembly includes a solenoid supported by the body and movable between a first position inhibiting rotation of the shaft relative to the body and a second position permitting rotation of the shaft relative to the body.

A seatbelt pretensioning retractor assembly for use in a passenger vehicle is provided. The pretensioning assembly includes a one-piece tread head pinion including a ring portion having a plurality of teeth and a pair of flanges on each side of the teeth. The tread head pinion is formed as a single piece and includes a shaft extending from a side and a bearing portion extending from a second side. A bending element mounting portion extends from the bearing portion. The one-piece tread head pinion is attached to a spindle via a torsion bar, and the spindle bears against the bearing portion when the spindle rotates relative to the tread head pinion. The one-piece tread head pinion may include a staking cavity extending into the bearing portion with a staking wall that is deformable toward a digressive bending element inserted into the staking cavity.

A seatbelt pretensioning retractor assembly for use in a passenger vehicle is provided. The pretensioning assembly includes a one-piece tread head pinion including a ring portion having a plurality of teeth and a pair of flanges on each side of the teeth. The tread head pinion is formed as a single piece and includes a shaft extending from a side and a bearing portion extending from a second side. A bending element mounting portion extends from the bearing portion. The one-piece tread head pinion is attached to a spindle via a torsion bar, and the spindle bears against the bearing portion when the spindle rotates relative to the tread head pinion. The one-piece tread head pinion may include a staking cavity extending into the bearing portion with a staking wall that is deformable toward a digressive bending element inserted into the staking cavity.

The present application discloses a child safety seat and a safety belt adjustment system thereof. The safety belt adjustment system includes: an automatic retracting device including a retracting shaft and a retractor, the retracting shaft being configured to be connected to a safety belt, the retractor driving the retracting shaft to perform a retracting rotation, so as to tension the safety belt in a buckled state; and a first locking device including a drive button and a locking member; the drive button being configured to drive the retracting shaft to perform a release rotation. The locking member has a locked position. In the locked position, the locking member locks the retracting rotation of the retracting shaft.