Seat belt retractor

Patent metadata

Field	Value
Publication number	US-10836347-B2
Application number	US-201816230513-A
Country	US
Kind code	B2
Filing date	Dec 21, 2018
Priority date	Dec 21, 2018
Publication date	Nov 17, 2020
Grant date	Nov 17, 2020

Abstract

A seat belt retractor that includes a torsion bar is positioned in a spool. The second end of the torsion bar is engaged with a locking mechanism mounted to the frame. The torsion bar is configured to be locked at the second end while the first end rotates with the spool so that the torsion bar deforms to absorb force. The locking mechanism includes a lock base and a locking hub that is mounted to the second end of the torsion bar and is releasably connected to the lock base to prevent the second end of the torsion bar from rotating. The locking hub is configured to be released and rotate relative to the lock base to thereby permit rotation of the second end of the torsion bar with the first end of the torsion bar and the spool.

First claim

What is claimed is:

1. A seatbelt retractor for a seat belt device in a vehicle, the retractor comprising:
a frame;
a spool configured to be fixed to one end of a webbing so that the webbing may be wound around the spool, the spool being rotatably mounted at both ends to the frame and configured to rotate in a webbing extraction direction and a webbing retraction direction;
a primary torsion bar positioned in the spool having a first end coupled to the spool and a second end configured to be locked; and
a secondary torsion bar positioned in the spool, a first end of the secondary torsion bar being coupled to the spool and a second end of the secondary torsion bar being engaged with a locking mechanism mounted to the frame;
a pretensioner configured to rotate the spool in a webbing retraction direction when the pretensioner activates in response to an acceleration of the vehicle greater than a predetermined high acceleration;
wherein the secondary torsion bar is configured to be locked at the second end and the first end being configured to rotate relative to the second end so that the secondary torsion bar deforms to absorb force; and
wherein the locking mechanism includes a lock base and a locking hub, wherein the lock base is locked to the frame when the vehicle experiences an acceleration greater than a predetermined value, and wherein the locking hub is mounted to the second end of the secondary torsion bar and is releasably connected to the lock base to prevent the second end of the secondary torsion bar from rotating when the lock base is locked;
wherein the locking hub is configured to be released and rotate relative to the lock base in response to a predetermined condition to thereby permit rotation of the second end of the secondary torsion bar with the first end of the secondary torsion bar and the spool.

2. The seat belt retractor of claim 1 , wherein the locking hub is prevented from rotating relative to the lock base by a release ring and a locking wedge.

3. The seat belt retractor of claim 2 , wherein the locking wedge engages a groove in the locking hub to prevent rotation of the second end of the secondary torsion bar relative to the lock base.

4. The seat belt retractor of claim 3 , wherein the release ring is connected to the lock base and includes an inward projection that contacts the locking wedge and prevents the locking wedge from moving outwardly to disengage from the groove.

5. The seat belt retractor of claim 4 , wherein the release ring is connected to the lock base by a shear pin so that when the shear pin is severed the release ring may rotate relative to the lock base.

6. The seat belt retractor of claim 5 , further comprising a movable release rod that is configured to drive the release ring with enough force to sever the shear pin thereby allowing the release ring to rotate.

7. The seat belt retractor of claim 6 , further comprising a pyrotechnic actuator for producing thrust to force the release rod into the release ring.

8. The seat belt retractor of claim 6 , wherein the release ring is configured to rotate to a position in which the inward projection no longer blocks outward movement of the locking wedge and wherein an edge of the groove is angled so that rotation of the locking hub with the second end of the secondary torsion bar forces the locking wedge to more outwardly out of engagement with the groove thereby allowing rotation of the second end of the secondary torsion bar with the first end of the secondary torsion bar and the spool.

9. The seat belt retractor of claim 1 , wherein the lock base includes a movable locking pawl that engages the frame in response to a predetermined vehicle acceleration to thereby prevent rotation of the locking base relative to the frame.

10. A seatbelt retractor for a seat belt device in a vehicle, the retractor comprising:
a frame;
a spool configured to be fixed to one end of a webbing so that the webbing may be wound around the spool, the spool being rotatably mounted at both ends to the frame and configured to rotate in a webbing extraction direction and a webbing retraction direction;
a primary torsion bar positioned in the spool, a first end of the primary torsion bar being coupled to a torsion bar cam, wherein the torsion bar cam is configured to engage the spool;
a secondary torsion bar positioned in the spool, a first end of the secondary torsion bar being connected to the torsion bar cam and a second end of the torsion bar being engaged with a locking mechanism mounted to the frame;
wherein a second end of the primary torsion bar is configured to be locked and the second end of the secondary torsion bar is configured to be locked and wherein the first end of the primary torsion and the first end of the secondary torsion bar are both configured to rotate so that the primary and secondary torsion bars twist and deform to absorb force;
wherein the locking mechanism includes a lock base and a locking hub, wherein the lock base is locked to the frame when the vehicle experiences an acceleration greater than a predetermined value, and wherein the locking hub is mounted to the second end of the secondary torsion bar and is releasably connected to the lock base to prevent the second end of the secondary torsion bar from rotating when the lock base is locked;
wherein the locking hub is configured to be released and rotate relative to the lock base in response to a predetermined condition to thereby permit rotation of the second end of the secondary torsion bar with the first end of the secondary torsion bar and the spool.

11. The seat belt retractor of claim 10 , wherein the locking hub includes a groove that is engaged with a locking wedge that prevents the locking hub and second end of the secondary torsion bar from rotating relative to the lock base.

12. The seat belt retractor of claim 11 , further comprising a release ring connected to the lock base and including an inward projection that contacts the locking wedge and prevents the locking wedge from moving outwardly to disengage from the groove.

13. The seat belt retractor of claim 12 , wherein the release ring is connected to the lock base by a shear pin so that when the shear pin is severed the release ring may rotate relative to the lock base.

14. The seat belt retractor of claim 13 , further comprising a movable release rod that is configured to drive the release ring with enough force to sever the shear pin thereby allowing the release ring to rotate relative to the lock base.

15. The seat belt retractor of claim 14 , further comprising a pyrotechnic actuator for producing thrust to force the release rod into the release ring.

16. The seat belt retractor of claim 15 , wherein the release ring is configured to rotate to a position in which the inward projection no longer blocks outward movement of the locking wedge and wherein an edge of the groove is angled so that rotation of the locking hub with the second end of the secondary torsion bar forces the locking wedge to more outwardly out of engagement with the groove thereby allowing rotation of the second end of the secondary torsion bar with the first end of the secondary torsion bar and the spool.

17. The seat belt retractor of claim 10 , further comprising a pretensioner for driving the spool in the webbing retraction direction and locking the second end of the primary torsion bar.

18. A seatbelt retractor for a seat belt device in a vehicle, the retractor comprising:
a frame;
a spool configured to be fixed to one end of a seat belt webbing so that the webbing may b

Assignees

• Joyson Safety Systems Acquisition Llc

Inventors

• Gray Mark

Classifications

• B60R22/3413

  operating between belt reel and retractor frame (B60R22/4676 takes precedence) · CPC title

• B60R22/28

  incorporating energy-absorbing devices {(belt anchors provided with energy-absorbing means for protecting the occupants in case of physical contact therewith B60R21/055; belt retractors comprising energy-absorbing means B60R22/341, B60R22/4676)} · CPC title

• B60R22/40 Primary

  responsive only to vehicle movement · CPC title

• B60R2022/3421

  with means for locking the belt reel in a non-use position, e.g. for seat mounted retractor when the seat is in a non-locked condition · CPC title

• B60R22/4676 Primary

  comprising energy-absorbing means operating between belt reel and retractor frame · CPC title