Retractor pretensioner assembly

Patent metadata

Field	Value
Publication number	US-9475455-B2
Application number	US-201414286087-A
Country	US
Kind code	B2
Filing date	May 23, 2014
Priority date	May 23, 2014
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

A pretensioner assembly for motor vehicle belt restraint systems is provided. The pretensioner assembly includes a tube in fluid communication with a gas generator and a polymer rod disposed therein that travels in a first direction in response to actuation of the gas generator. The polymer rod is plastically deformable and engages a sprocket to rotate the sprocket in response to the travel of the rod, where rotation of the sprocket causes pretensioning. The rod has a non-constant cross-section along its length. The rod becomes locked after actuation to prevent travel in an opposite direction. The system further includes a seal member and slug member disposed between the rod and the gas generator, where the seal member is relatively flexible and the slug member is relatively hard.

First claim

The invention claimed is:

1. A seatbelt pretensioning retractor assembly for use in a passenger vehicle, the system comprising:
a housing adapted for being mounted to a vehicle structure;
a tube having an arcuate and curved shape having a first end in fluid communication with a gas generator and an exit in fluid communication with an interior cavity of the housing;
a sprocket rotatably mounted to the housing and fixedly coupled to a spindle adapted for taking up seatbelt webbing during pretensioning, the sprocket having a plurality of vanes;
a curved guide of the housing disposed on an opposite side of the sprocket from the exit of the tube;
a polymer rod disposed within the tube and having a non-constant cross-section with a main body portion and an enlarged portion, wherein the polymer rod is plastically deformable;
wherein the polymer rod exits the tube, along a perimeter of the sprocket, and toward the curved guide in response to an actuation by the gas generator to rotate the sprocket and spindle to take up seatbelt webbing; and
wherein the curved guide includes a plurality of one-way teeth.

2. The seatbelt pretensioning retractor assembly of claim 1
wherein the polymer rod includes a proximal end and a distal end, wherein the proximal end is disposed toward the gas generator and the distal end is disposed away from the gas generator, and the enlarged portion is disposed at the proximal end for receiving a load in response to actuation of the gas generator; and
wherein the polymer rod includes a constant cross-section extending from an end of the enlarged portion to the distal end of the polymer rod, wherein the enlarged portion has a solid cross-section.

3. The assembly of claim 1 , wherein the one-way teeth permit translation of the rod from the tube in a first direction and limit translation of the rod in a second direction opposite the first direction.

4. The assembly of claim 1 , wherein the vanes of the sprocket plastically deform the polymer rod in response to the polymer rod engaging the sprocket.

5. The assembly of claim 1 , wherein the tube defines a passageway extending therethrough from the first end to the second end and includes a constriction adjacent the exit of the tube, where the constriction reduces a width of the passageway.

6. The assembly of claim 1 , further comprising a seal member disposed within the tube between the generator and the enlarged end of the polymer rod, and further comprising a stopper member disposed between the seal member and the polymer rod, wherein the seal member and the stopper member have a ball shape, and the seal member has a greater diameter than the stopper member.

7. The assembly of claim 1 , further comprising a seal member disposed within the tube between the generator and the enlarged end of the polymer rod, and further comprising a stopper member disposed between the seal member and the polymer rod, wherein the seal member is made of rubber and the stopper member is made of aluminum.

8. The assembly of claim 1 , further comprising a seal member disposed within the tube between the generator and the enlarged end of the polymer rod, and further comprising a stopper member disposed between the seal member and the polymer rod, wherein the seal member and the stopper member are fixed to each other, the seal member comprising a rubber portion and the stopper member comprising an aluminum portion, where the aluminum portion is disposed between the rubber portion and the polymer rod.

9. The assembly of claim 1 , wherein the vanes each have a base portion that tapers down radially outward and the base has a first radius on one side of the vane and a second radius on the other side of the vane.

10. A seatbelt pretensioning retractor assembly for use in a passenger vehicle, the system comprising:
a housing adapted for being mounted to a vehicle structure;
a tube having an arcuate and curved shape having a first end in fluid communication with a gas generator and an exit in fluid communication with an interior cavity of the housing;
a sprocket rotatably mounted to the housing and fixedly coupled to a spindle adapted for taking up seatbelt webbing during pretensioning, the sprocket having a plurality of vanes;
a curved guide of the housing disposed on an opposite side of the sprocket from the exit of the tube;
a polymer rod disposed within the tube and having a non-constant cross-section with a main body portion and an enlarged portion, wherein the polymer rod is plastically deformable;
wherein the polymer rod exits the tube, along a perimeter of the sprocket, and toward the curved guide in response to an actuation by the gas generator to rotate the sprocket and spindle to take up seatbelt webbing; and
wherein the polymer rod welds to the curved guide in response to the actuation by the gas generator and translation of the polymer rod into engagement with the curved guide at an interface, and the polymer rod and a portion of the guide along the interface are made of the same material, such that heat generated between the polymer rod and the guide at the interface locks and welds the polymer rod to the curved guide.

11. The seatbelt pretensioning retractor assembly of claim 10 , wherein the polymer rod includes a proximal end and a distal end, wherein the proximal end is disposed toward the gas generator and the distal end is disposed away from the gas generator, and the enlarged portion is disposed at the proximal end for receiving a load in response to actuation of the gas generator; and
wherein the polymer rod includes a constant cross-section extending from an end of the enlarged portion to the distal end of the polymer rod, wherein the enlarged portion has a solid cross-section.

12. The assembly of claim 10 , wherein the vanes of the sprocket plastically deform the polymer rod in response to the polymer rod engaging the sprocket.

13. The assembly of claim 10 , wherein the tube defines a passageway extending therethrough from the first end to the second end and includes a constriction adjacent the exit of the tube, where the constriction reduces a width of the passageway.

14. The assembly of claim 10 , further comprising a seal member disposed within the tube between the generator and the enlarged end of the polymer rod, and further comprising a stopper member disposed between the seal member and the polymer rod, wherein the seal member and the stopper member have a ball shape, and the seal member has a greater diameter than the stopper member.

15. The assembly of claim 10 , further comprising a seal member disposed within the tube between the generator and the enlarged end of the polymer rod, and further comprising a stopper member disposed between the seal member and the polymer rod, wherein the seal member is made of rubber and the stopper member is made of aluminum.

16. The assembly of claim 10 , further comprising a seal member disposed within the tube between the generator and the enlarged end of the polymer rod, and further comprising a stopper member disposed between the seal member and the polymer rod, wherein the seal member and the stopper member are fixed to each other, the seal member comprising a rubber portion and the stopper member comprising an aluminum portion, where the aluminum portion is disposed between the rubber portion and the polymer rod.

17. The assembly of claim 10 , wherein the vanes each have a base portion that tapers down radially outward and the base has a first radius on one side of the vane and a second radius on the other side of the vane.

18. A seatbelt retracto

Assignees

• Autoliv Asp
• Autoliv Asp Inc

Inventors

• Gray Mark F
• Kohlndorfer Kenneth H

Classifications

• B60R22/4628 Primary

  characterised by fluid actuators, e.g. pyrotechnic gas generators (actuating a cable B60R22/4619) · CPC title

• B60R2022/468

  characterised by clutching means between actuator and belt reel · CPC title

• B60R2022/4642

  the gas directly propelling a flexible driving means, e.g. a plurality of successive masses, in a tubular chamber · CPC title