Granted Patent B2

US 9,555,766 · App. 15/021,637 · Granted Jan 31, 2017

Abstract

Claims (30)

1. A seatbelt retractor comprising:

a frame;

a seatbelt;

a spool that takes up the seatbelt, the spool being rotatably supported by the frame;

a lock mechanism that allows the spool to rotate in a non-activated state and restricts, upon being activated, the spool from rotating in a seatbelt withdrawal direction; and

an energy absorption mechanism that limits a load applied to the seatbelt to thereby absorb and alleviate energy of an occupant,

wherein the energy absorption mechanism includes:

a first torsion bar concentrically enclosed in the spool with one end portion retained by the spool and an opposite end portion disposed to be locked by the lock mechanism, and disposed to be rotated by torsional force;

a second torsion bar eccentrically enclosed in the spool with one end portion disposed to be locked by the lock mechanism, and disposed to be rotated by torsional force; and

a moving member that rotates interlocked with the spool, and moves between a first position for retaining an opposite end portion of the second torsion bar and a second position spaced from the opposite end portion of the second torsion bar.

2. The seatbelt retractor according to claim 1 ,

wherein the energy absorption mechanism includes:

a first gear that retains the other end portion of the first torsion bar, the first gear being disposed to be locked by the lock mechanism; and

a second gear meshed with the first gear and retaining the one end portion of the second torsion bar.

3. The seatbelt retractor according to claim 1 ,

wherein the energy absorption mechanism includes:

a pressing member that moves the moving member to the first position and the second position;

a drive mechanism that drives the pressing member; and

a housing movably supporting the pressing member and accommodating therein the drive mechanism.

4. The seatbelt retractor according to claim 3 ,

wherein the housing includes a cam portion spaced from the pressing member before the drive mechanism is activated, and contacted by the pressing member when the drive mechanism is activated.

5. The seatbelt retractor according to claim 4 , further comprising:

an occupant information acquisition unit that acquires occupant information; and

a control unit that decides whether the information acquired by the occupant information acquisition unit satisfies a predetermined condition, and moves the moving member, depending on a decision result, to the first position for retaining the opposite end portion of the second torsion bar and the second position spaced from the opposite end portion of the second torsion bar.

6. The seatbelt retractor according to claim 5 , further comprising a pretensioner mechanism that rotates the spool in a seatbelt retracting direction in an emergency case,

wherein the control unit decides whether the information acquired by the occupant information acquisition unit satisfies the predetermined condition, after activating the pretensioner mechanism in the emergency case.

7. A seatbelt assembly comprising at least:

the seatbelt retractor of claim 1 that withdrawably retracts the seatbelt and restricts the seatbelt from being withdrawn upon being activated in an emergency case;

a tongue slidably supported by the seatbelt withdrawn from the seatbelt retractor; and

a buckle attached to a vehicle body or a vehicle seat to be removably engaged with the tongue.

Assignments (7)