Belt retractor for a seat-belt

Patent metadata

Field	Value
Publication number	US-9796356-B2
Application number	US-201314431334-A
Country	US
Kind code	B2
Filing date	Sep 25, 2013
Priority date	Sep 27, 2012
Publication date	Oct 24, 2017
Grant date	Oct 24, 2017

Abstract

A belt retractor ( 10 ) for a seat belt comprising a belt reel ( 20 ), a belt tensioner ( 44 ) adapted to drive the belt reel ( 20 ) in a winding direction and an extension limiter ( 16 ) adapted to restrict the number of revolutions of the belt reel ( 20 ) in an unwinding direction in the activated state. The extension limiter ( 16 ) is communicated with the belt tensioner ( 44 ) so that the extension limiter ( 16 ) can only be activated after the belt tensioner ( 44 ) has been activated.

First claim

The invention claimed is:

1. A belt retractor ( 10 ) for a seat belt comprising a belt reel ( 20 ), a locking mechanism ( 12 ) and a force limiter ( 14 ), a belt tensioner ( 44 ) adapted to drive the belt reel ( 20 ) in a winding direction and an extension limiter ( 16 ) adapted to limit the number of revolutions of the belt reel ( 20 ) after the locking mechanism ( 12 ) is triggered in an unwinding direction in the activated state, the extension limiter ( 16 ) being communicated with the belt tensioner ( 44 ) so that the extension limiter ( 16 ) can only be activated after the belt tensioner ( 44 ) has been activated.

2. The belt retractor ( 10 ) according to claim 1 , wherein the extension limiter ( 16 ) includes a stop catch ( 32 ) and a retaining member ( 30 ) adjustable between a retaining position in which the stop catch ( 32 ) is held in a deactivated position and a release position in which the stop catch ( 32 ) is released.

3. The belt retractor ( 10 ) according to claim 2 , wherein a spring ( 34 ) is provided for loading the stop catch ( 32 ) from the deactivated position to an engaged position.

4. The belt retractor ( 10 ) according to claim 2 , wherein the extension limiter ( 16 ) includes a limiting ring ( 62 ) which is arranged to be twistable to a limited extent and in which the stop catch ( 32 ) can engage.

5. The belt retractor ( 10 ) according to claim 2 , wherein an actor ( 84 ) for the stop catch ( 3 ) is provided which is triggered by the trigger signal for a belt tensioner ( 44 ).

6. The belt retractor ( 10 ) according to claim 1 , wherein a switch element ( 28 ) is provided which is adjusted upon activation of the belt tensioner ( 44 ).

7. The belt retractor ( 10 ) according to claim 6 , wherein the switch element ( 28 ) is spring-loaded and can be adjusted from a home position in which the extension limiter ( 16 ) is deactivated to a release position in which the extension limiter ( 16 ) is activated.

8. The belt retractor ( 10 ) according to claim 6 , wherein the switch element ( 28 ) is a pin that is movably supported in the belt reel ( 20 ).

9. The belt retractor ( 10 ) according to claim 6 , wherein in the home position the switch element ( 28 ) is supported on a force transmission element ( 42 ) of the belt tensioner ( 44 ).

10. The belt retractor ( 10 ) according to claim 9 , wherein the force transmission element ( 42 ) includes a force transmission wheel ( 48 ) and a switch wheel ( 46 ) which are rotatable relative to each other.

11. The belt retractor ( 10 ) according to claim 10 , wherein the switch wheel ( 46 ) is provided with recesses ( 56 ), the switch element ( 28 ) being adapted to immerse into one of the recesses ( 56 ).

12. The belt retractor ( 10 ) according to claim 10 , wherein the switch wheel ( 46 ) is loaded by the belt tensioner ( 44 ).

13. The belt retractor ( 10 ) according to claim 10 , wherein the force transmission wheel ( 48 ) is loaded by the belt tensioner ( 44 ).

14. The belt retractor ( 10 ) according to claim 6 , wherein the belt tensioner ( 44 ) includes at least one push element ( 54 ) being adjusted after triggering of the belt tensioner ( 44 ) so as to drive the belt reel ( 20 ) in the winding direction, and in that the switch element ( 28 ) is adjusted by the push element ( 54 ).

15. The belt retractor ( 10 ) according to claim 6 , wherein the switch element ( 28 ) is a lever which can be adjusted from a home position in which the extension limiter ( 16 ) is deactivated to a release position in which the extension limiter ( 16 ) is activated.

16. The belt retractor ( 10 ) according to any claim 6 , wherein the switch element ( 28 ) is supported on the frame ( 18 ) of the belt retractor ( 10 ).

17. The belt retractor ( 10 ) according to claim 6 , wherein the switch element ( 28 ) is pivoting about an axis extending in parallel to the central axis of the belt reel ( 20 ).

18. The belt retractor ( 10 ) according to claim 1 , wherein a retaining member ( 30 ) is provided which is supported to be rotatable on the belt reel ( 20 ), the retaining member ( 30 ) being detachably held in a retaining position by a locking device ( 76 ).

19. The belt retractor ( 10 ) according to claim 18 , wherein the retaining member ( 30 ) is an inertia element which is rotatably arranged on the belt reel ( 20 ).

20. The belt retractor ( 10 ) according to claim 18 , wherein the locking device ( 76 ) is a locking tab the locking effect of which is overcome, when a predetermined torque acts between the retaining member ( 30 ) and the belt reel ( 20 ).

21. The belt retractor ( 10 ) according to claim 18 , wherein the locking device ( 76 ) is adapted to hold the retaining member ( 30 ) in a release position.

Assignees

• Trw Automotive Gmbh

Inventors

• Hertäg Beate
• Dambacher Steffen
• Landbeck Adrian

Classifications

• B60R22/46 Primary

  {Reels} with means to tension the belt in an emergency {by forced winding up}(electrical circuits for triggering safety arrangements B60R21/01 {; tensioners using reels only guiding the belt during normal use, e.g. splitted reels B60R22/195}) · 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

• B60R22/341

  comprising energy-absorbing means · CPC title

• 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