Patent ID: 6416008
Filing Date: 2002-07-09
Classification: B60R

Abstract:
A seatbelt retractor comprising at least:a spool for taking up a seatbelt; a lock mechanism having a locking member whereby rotation in the direction of extracting the seatbelt is obstructed in the event of an emergency; a torsion bar rotatably linking said spool and said locking member, and capable of being deformed by twisting; and a seatbelt load restricting mechanism for restricting the load placed upon said seatbelt wherein said torsion bar deforms by twisting at the time that the rotation of said locking member in the direction of said seatbelt being extracted is obstructed and said spool rotates relative to the extracting direction of said seatbelt; wherein the restriction load properties of said seatbelt load restricting mechanism comprise a relatively small restriction load due to twisting deformation of said torsion bar alone, and a relatively great restriction load made up of a restriction load due to twisting deformation of said torsion bar and a restriction load due to another member, and wherein said relatively great restriction load is set to have properties which change in at least two steps; wherein said seatbelt load restricting mechanism further comprises a predetermined number of share pins provided between said spool and said locking member such that a shearing load is placed thereupon at the time of said relative rotation of said spool, wherein said restriction load initially greatly increases the shearing load on said share pins and is set to a constant load by the twisting load of said torsion bar following the shearing destruction of said share pins; and wherein an indented portion is formed in said share pins, and the relative rotation position of said spool is set such that said share pins break under shearing at this indented portion.