Method and device for a safety belt

• US 6,637,772 B1
• Filed: 01/30/2001
• Issued: 10/28/2003
• Est. Priority Date: 05/20/1998
• Status: Expired due to Fees

• Current Assignee: Saab Automobile AB (China Evergrande Group)
• Original Assignee: Saab Automobile AB (China Evergrande Group)
• Inventors: Hedlund, Alf, Fägerhag, Mats, Viano, David C., Wiklund, Kristina
• Primary Examiner(s): CULBRETH, ERIC D
• Application Number:
  US09/700,584
• Time in Patent Office: 1,001 Days
• Field of Search: 280/806, 280/805, 180/268, 297/470, 297/476, 297/477, 297/478, 297/479, 297/480
• US Class Current: 280/806
• CPC Class Codes: B60R 2021/01311 monitoring the braking system, e.g. ABS
• CPC Class Codes: B60R 2022/285 using friction surfaces
• CPC Class Codes: B60R 2022/4609 using a plurality of tensioners
• CPC Class Codes: B60R 2022/4666 characterised by electric actuators
• CPC Class Codes: B60R 2022/468 characterised by clutching means between actuator and belt reel
• CPC Class Codes: B60R 2022/469 reusable
• CPC Class Codes: B60R 21/0134 responsive to imminent contact with an obstacle , e.g. using radar systems
• CPC Class Codes: B60R 22/46 Reels with means to tension the belt in an emergency by forced winding upelectrical circuits for triggering safety arrangements B60R21/01 ; tensioners using reels only guiding the belt during normal use, e.g. splitted reels B60R22/195
• CPC Class Codes: B60R 22/4628 characterised by fluid actuators, e.g. pyrotechnic gas generators actuating a cable B60R22/4619
• CPC Class Codes: B60R 22/4676 comprising energy-absorbing means operating between belt reel and retractor frame

Abstract

For a safety belt (2) in a vehicle, the belt is tightened in the event of a collision for at least 300 ms, at the same time as the maximum pull on the safety belt is limited to a predetermined value during the whole tightening process. This is made possible by a tightening device (15) being arranged to be able to operate for at least 300 ms and by there being a load-limiting device (14) between the tightening device (15) and the belt.

Claims

1. A method for restraining a belt wearer in a vehicle in the event of a collision by means of a safety belt comprising the steps of:

reaching a predetermined retardation level for the vehicle;

tightening the safety belt, wherein the step of tightening occurs for a period of at least 300 ms and begins after the beginning of the collision; and

limiting a maximum pull on the safety belt to a predetermined value during a whole tightening process, wherein the limited maximum pull reduces a risk of injury to the belt wearer.

2. The method according to claim 1, wherein the step of tightening occurs for at least 800 ms.

3. The method according to claim 1, wherein the step of tightening comprises a tightening force that is at least as great as the limited maximum pull on the safety belt.

4. The method according to claim 1, wherein the limited maximum pull on the safety belt is within a range of 2.0 kN to 3.5 kN.

5. The method according to claim 1, wherein the step of tightening is preceded by a step of preparatory tightening which is initiated before the collision.

6. The method according to claim 5, wherein the step of preparatory tightening is initiated as a function of the retardation of the vehicle.

7. The method according to claim 5, wherein the step of preparatory tightening is initiated as a function of a distance to an object in front of the vehicle.

8. The method according to claim 5, wherein the step of preparatory tightening is continual and there is a continual transition into the step of tightening.

9. The method according to claim 5, wherein the step of preparatory tightening is preceded by a step of gentle tightening that is initiated as a function of the vehicle'"'"'s driving situation with a lower tightening force than during the preparatory tightening.

10. The method according to claim 1, wherein the step of tightening is preceded by a step of gentle tightening that is initiated as a function of the vehicle'"'"'s driving situation with a lower tightening force than during the step of tightening.

11. The method according to claim 1, wherein the step of tightening is carried out in a part of the safety belt which passes over a shoulder of the belt wearer.

12. A device for a safety belt in a vehicle, where the safety belt is acted upon by a tightening device and is arranged to be tightened around a belt wearer, comprising:

a load-limiting device for limiting a maximum pull on the safety belt;

wherein the tightening device can be activated in the event of a collision to tighten the safety belt and the tightening device is arranged to be able to operate for a period of at least 300 ms starting after the beginning of the collision and that the load-limiting device is arranged to operate between the belt and the tightening device.

13. The device according to claim 12, wherein the tightening device is arranged to be able to operate for at least 800 ms.

14. The device according to claim 12, wherein the tightening device is arranged to exert a tightening force which is at least as large as the maximum permitted pull on the safety belt.

15. The device according to claim 12, wherein the load-limiting device is a friction connection.

16. The device according to claim 12, wherein the tightening device is arranged to be able to tighten the safety belt at a speed of 5-10 m/s and to be able to wind up at least 140 mm of safety belt.

17. The device according to claim 15, wherein the load-limiting device is arranged to permit a maximum pull on the safety belt within a range of 2.0 kN to 3.5 kN.

18. The device according to claim 12, wherein the tightening device is initially operated by a gas.

19. The device according to claim 18, wherein the tightening device is operated by gas throughout the whole of its period of operation.

20. The device according to claim 12, wherein the tightening device comprises an electric motor.

21. The device according to claim 12, wherein the tightening device is activated before a collision, for a preparatory tightening.

22. The device according to claim 21, wherein the tightening device is activated as a function of a retardation of the vehicle.

23. The device according to claim 22, wherein a gentle tightening is activated as a function of a driving situation of the vehicle and the gentle tightening is performed with a lower force than during the preparatory tightening.

24. The device according to claim 21, wherein the tightening device is activated as a function of a distance to an object in front of the vehicle.

25. The device according to claim 21, wherein the tightening device is operated by electricity at least during the preparatory tightening.

26. The device according to claim 12, wherein the tightening device causes a gentle tightening as a function of the driving situation of the vehicle, wherein the gentle tightening comprises a lower force than during a main tightening.

27. The device according to any of claim 12, further comprising a part of the safety belt which passes over a shoulder of the belt wearer.