Seatbelt pretensioner

• US 9,669,799 B2
• Filed: 03/15/2013
• Issued: 06/06/2017
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Original Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Inventors: Hoffman, Isaac, Nelson, Earl Henry, Kock, Hans-Otto
• Primary Examiner(s): KIM, SANG K
• Application Number:
  US13/833,992
• Publication Number:
  US 20140263809A1
• Time in Patent Office: 1,544 Days
• CPC Class Codes: B60R 2022/4638 comprising a piston moving along or in parallel to the reel axis
• CPC Class Codes: B60R 2022/468 characterised by clutching means between actuator and belt reel
• CPC Class Codes: B60R 22/4633 Linear actuators, e.g. comprising a piston moving along reel axis and rotating along its own axis

Abstract

A seatbelt pretensioner is provided including an inner tube with a gas generator housed therein, an intermediate sleeve extending over the inner tube, and a spool portion housing the sleeve and the tube. The spool portion includes spiraling flutes thereon that correspond to a protruding member in the form of flutes or pegs extending from the intermediate sleeve. In response to the gas generator firing, the sleeve will be driven longitudinally, causing the protruding member to act on the spiraling flutes of the spool, thereby causing the spool to rotate. The intermediate sleeve can include a spiraling slot that receives a peg from the inner tube, so that the intermediate sleeve will rotate to compound the spool rotation.

Claims

1. A seatbelt pretensioning system for acting on a seatbelt of an occupant restraint system of a motor vehicle, the system comprising:

a rotatable spool having a generally cylindrical sidewall defining a central longitudinal axis and a cavity centered on the longitudinal axis;

a longitudinally translatable sleeve having a generally cylindrical sidewall that is coaxially aligned with the longitudinal axis and defining a cavity therein, the sleeve being mounted within the cavity of the spool for longitudinal translation therein;

a spiraling flute formed by either the spool sidewall within the cavity or the translatable sleeve, and a follower member formed by the other of the spool sidewall or translatable sleeve, wherein the follower member is coupled to the spiraling flute;

a tube member having a generally cylindrical sidewall and defining a cavity therein, the tube being mounted within the sleeve sidewall, wherein the sleeve is translatable along the tube, wherein the cavity of the tube extends from a first end of the generally cylindrical sidewall of the tube member to a second end of the generally cylindrical sidewall of the tube member;

a gas generator fluidly coupled to the tube cavity and being configured to produce an increase in pressure within the tube cavity, wherein the sleeve translates longitudinally away from the gas generator and along the tube in response to the increase in pressure caused by the gas generator, wherein the gas generator is in fluid communication with the cavity of the tube member from the first end to the second end thereof such that gas generated by the gas generator will fill the cavity of the tube member; and

wherein the longitudinal translation of the sleeve causes the spool to rotate in response in accordance with the shape of the spiraling flute and its coupling to the follower member to cause the seatbelt to be pretensioned.

2. The system of claim 1, wherein the spiraling flute is formed by the spool and the follower member is formed on the sleeve, and the follower member extends into the spiraling flute.

3. The system of claim 2, wherein the follower member comprises a second spiraling flute.

4. The system of claim 2, wherein the protrusion comprises a round peg.

5. The system of claim 1, wherein the tube includes a protrusion extending therefrom, the sleeve includes a slot that receives the protrusion, and the sleeve is rotationally controlled by the protrusion and the slot.

6. The system of claim 5, wherein the slot spirals about the sleeve and the sleeve rotates in response to longitudinal translation thereof.

7. The system of claim 5, wherein the slot extends longitudinally along the sleeve and the sleeve is generally limiting from rotation in response to longitudinal translation thereof.

8. The system of claim 1, wherein the spool includes an opening at one end and the sleeve partially extends out of the opening when the sleeve has translated longitudinally.

9. The system of claim 1, wherein the spool rotates relative to the tube via a bearing connection therebetween.

10. The system of claim 9, wherein the bearing connection comprises a plain bearing.

11. The system of claim 9, wherein the spool is disposed within a head portion of the tube and the spool bears against an inner surface of the head portion.

12. The system of claim 9, wherein the spool includes a cylindrical recess, and a head portion of the tube is disposed within the recess and bears against an inner surface of the recess.

13. A seatbelt pretensioning system for acting on a seatbelt of an occupant restraint system of a motor vehicle, the system comprising:

a rotatable spool having a generally cylindrical sidewall defining a central longitudinal axis and a cavity centered on the longitudinal axis;

a longitudinally translatable sleeve having a generally cylindrical sidewall that is coaxially aligned with the longitudinal axis and defining a cavity therein, the sleeve being mounted within the cavity of the spool for longitudinal translation therein;

a spiraling flute formed by either the spool sidewall within the cavity or the translatable sleeve, and a follower member formed by the other of the spool sidewall or translatable sleeve, wherein the follower member is coupled to the spiraling flute;

a tube member having a generally cylindrical sidewall and defining a cavity therein, the tube being mounted within the sleeve sidewall, wherein the sleeve is translatable along the tube;

a gas generator fluidly coupled to the tube cavity and being configured to produce an increase in pressure within the tube cavity, wherein the sleeve translates longitudinally away from the gas generator and along the tube in response to the increase in pressure caused by the gas generator; and

wherein the longitudinal translation of the sleeve causes the spool to rotate in response in accordance with the shape of the spiraling flute and its coupling to the follower member to cause the seatbelt to be pretensioned;

wherein the sleeve includes a first end and a second end of the sidewall of the sleeve, the first end being open and the second end being closed by an endwall, wherein the second end of the sleeve is disposed longitudinally further from the gas generator than the first end.

14. A seatbelt pretensioning device comprising:

a rotatable spool member having a generally cylindrical sidewall defining a central longitudinal axis and a spool cavity;

a spiraling flute spiraling in a first direction formed in the spool sidewall within the cavity;

a longitudinally translatable intermediate sleeve having a generally cylindrical sidewall and defining a drive member cavity therein, the intermediate sleeve being mounted within the spool cavity and coupled to the spiraling flute;

a spiraling slot having a helical shape and extending through the sidewall of the intermediate sleeve that spirals in a second direction that is generally opposite the direction of the spiraling flute;

a peg extending radially outward from the sidewall of the intermediate sleeve and extending into the spiraling flute of the spool;

a tube having a generally cylindrical sidewall and defining a tube cavity therein, the tube being disposed at least partially within the drive member cavity, wherein the intermediate sleeve is translatable and rotatable relative to the tube;

a second peg extending radially outward from the sidewall of the tube and extending into the spiraling slot of the intermediate sleeve;

a gas generator fluidly coupled to the tube cavity and being configured to produce an increase in pressure within the tube cavity to force the intermediate sleeve away from the gas generator; and

wherein the intermediate sleeve, in response to the increase in pressure within the tube cavity, translates away from the gas generator and rotates in a first direction due to the interaction between the second peg and the spiraling slot of the intermediate sleeve, and the first peg of the intermediate sleeve acts on the spiraling flute of the spool thereby rotating the spool to pretension the seatbelt.

15. The device of claim 14, wherein the intermediate sleeve is limited from translating and rotating when the second peg of the inner tube contacts an end of the spiraling slot of the intermediate sleeve.

16. The device of claim 14, wherein the spool portion includes an open end and the intermediate sleeve extends at least partially out of the open end when then sleeve has stopped rotating and translating.

17. The device of claim 14, wherein the intermediate sleeve has a first non-deployed condition with the first peg disposed a first longitudinal distance from the second peg and a second deployed condition with the first peg disposed a second longitudinal distance from the second peg that is smaller than the first longitudinal distance, wherein the device transitions from the first non-deployed condition to the second deployed condition when the gas generator is activated to translate the intermediate sleeve.

18. The system of claim 14, wherein the intermediate sleeve includes a first end and a second end of the sidewall of the sleeve, wherein the first end is open and the second end is closed by an endwall disposed at the second end of the of the sidewall, the endwall being further from the gas generator than the first end.