US Patent 7392957 Seatbelt retractor system and seatbelt system

A seatbelt retractor system allowing optimization of energy absorbing characteristics, includes a spool for retracting a seatbelt; a torsion bar made of a twistable material; a locking mechanism for stopping the rotation of the spool at least in a seatbelt withdrawing direction; a substantially disk shaped ring disposed in the inner periphery of an axial end of the spool; and a plastically deformable energy absorbing member. The energy absorbing member may have a substantially circular cross section. A first end of the energy absorbing member may be fixed to an outer periphery of the substantially disc-shaped ring, while a second end of the energy absorbing member may be detachably engaged with an inner periphery of the spool.