US 6,474,587 B2Granted

Seat belt retractor

AssigneeTakata Corporation

InventorsYasushi Kanamori, Joji Mishina, Masahiro Shiotani

Life of this patent

Estimating the term…

Loading patent…

Abstract

A seat belt retractor with a torsion bar which can receive a large torque and can be easily formed by forging is provided. A reel assembly of the seat belt retractor includes a reel, a torsion bar, and a locking member. A first connection part of the torsion bar non-rotatably couples with concavities of a locking base of the locking member. A second connection part non-rotatably couples with concavities of the reel. The outer peripheries of the connection parts and are torx-shaped having a plurality of concavities and convexities formed in a wave-shape. A ratio R1/R2 of the distance between the tops of the wave-shaped convexities of the connection parts and the axial center of the torsion bar (radius R1) to the distance between the bottoms of the concavities and the axial center of the torsion bar (radius R2) is set to 1.2 to 1.3.

Claims5

Dependent claims

A seat belt retractor comprising:

a reel for spooling a seat belt;
a locking mechanism for locking the rotation of the reel;
and
a forged torsion bar having a first connection part non-rotatably connected to the reel at one end of the torsion bar and a second connection part non-rotatably connected to the locking mechanism at the other end of the torsion bar,
wherein the first and second connection parts are torx-shaped having a plurality of concavities and convexities formed in a wave-shape, and
wherein concavities are formed in the reel and the locking mechanism structure for locking the rotation of the reel are formed in a torx-shape corresponding to the shape of the connecting parts with which the reel and the structure for locking the rotation of the reel are respectively connected;
and
wherein a ratio R1/R2 of the distance between the tops of the convexities formed in the wave-shape and the axial center of the torsion bar (radius R1) to the distance between the bottoms of the concavities and the axial center of the torsion bar (radius R2) is between 1.1 and 1.3.

5 more elements

Dependencies are inferred from the claim text.