Seat belt retractor

• US 6,290,159 B1
• Filed: 11/03/1999
• Issued: 09/18/2001
• Est. Priority Date: 01/22/1999
• Status: Expired due to Term

• Current Assignee: Key Safety Systems, Inc. (Ningbo Junsheng Investment Group Co., Ltd.)
• Original Assignee: Breed Automotive Technology, Inc. (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Specht, Martin, Kilian, Thomas, Krauss, Walter
• Primary Examiner(s): Jillions, John M.
• Application Number:
  US09/433,169
• Time in Patent Office: 685 Days
• Field of Search: 242/379.1, 242/383, 280/805, 280/806, 297/470, 297/471, 297/472, 180/268, 180/45, 701/47
• US Class Current: 242/379.1
• CPC Class Codes: B60R 2022/282 using fluids or vico-elastic materials
• CPC Class Codes: B60R 2022/284 using electric or magnetic braking means
• CPC Class Codes: B60R 2022/285 using friction surfaces
• CPC Class Codes: B60R 2022/287 of torsion rods or tubes
• CPC Class Codes: B60R 2022/288 with means to adjust or regulate the amount of energy to be absorbed
• CPC Class Codes: B60R 22/3413 operating between belt reel and retractor frame B60R22/4676 takes precedence

Abstract

A seat belt retractor has a belt reel for the seat belt webbing. A load limiter allows limited extraction of the belt webbing with energy absorption when the belt reel is blocked. The absorption of energy is adjustable as a function of crash-related data and the rotating movement of the belt reel is scanned for this purpose when the extraction of the belt webbing is limited.

Claims

1. A seat belt retractor comprising a belt reel for a seat belt webbing, a load limiter which allows limited extraction of the belt webbing with energy absorption when the belt reel is blocked, an adjusting device which adjusts the load limiter as a function of crash-related data, and a scanner for generating a measurement signal derived from a rotating movement of the belt reel, wherein said scanner measures an extracted length of belt webbing and/or a velocity of extraction of belt webbing and/or an acceleration of extraction of belt webbing;

wherein the crash-related data is indirectly determined by the rotating movement of the belt reel, wherein the scanner scans co-rotating components of the belt reel, said co-rotating components are markings or teeth of a set of blocking teeth of the belt reel applied to the belt reel at equal angular intervals.

2. The seat belt retractor according to claim 1, wherein the co-rotating components are at identical rotational angle intervals from one another.

3. The seat belt retractor according to claim 1 wherein the measurement signal is compared with a belt force characteristic field and the load limiter is adjusted as a function of the comparison.

4. The seat belt retractor according to claim 1 wherein the load limiter comprises at least one energy absorber with variable energy absorption that is adjusted as a function of the measurement signal or of the measurement signals.

5. The seat belt retractor according to claim 4 wherein the variable energy absorber is a hydraulic pump, an electric motor or as a rotary cam adjuster.

6. The seat belt retractor according to claim 4 wherein the variable energy absorber is a hydraulic pump.

7. The seat belt retractor according to claim 4 wherein the variable energy absorber is an electric motor.

8. The seat belt retractor according to claim 4 wherein the variable energy absorber is a rotary cam adjuster.

9. The seat belt retractor according to claim 1 wherein the load limiter comprises at least one energy absorber with predetermined energy absorption.

10. The seat belt retractor according to claim 1 wherein the load limiter comprises a plurality of selectively cumulatively switchable energy absorbers.

11. The seat belt retractor according to claim 1 wherein the energy absorption of the load limiter can be adjusted stepwise as a function of the belt reel rotational speed.

12. The seat belt retractor according to claim 1 wherein the load limiter is a hydraulic pump.

13. The seat belt retractor according to claim 12 wherein a fluid is displaced by the hydraulic pump through a cross section of flow which can be adjusted by a controllable valve.

14. The Seat belt retractor according to claim 13 wherein the fluid displaced by the hydraulic pump is displaced in a closed circuit containing the valve.

15. The seat belt retractor according claim 13 wherein the valve is adjusted as a function of crash-related data.

16. The seat belt retractor according claim 14 wherein the valve is adjusted as a function of crash-related data.