Safety-belt arrangement

• US 20040113409A1
• Filed: 11/19/2003
• Published: 06/17/2004
• Est. Priority Date: 02/06/2001
• Status: Active Grant

• Current Assignee: Autoliv AB (Autoliv Incorporated)
• Original Assignee: Autoliv AB (Autoliv Incorporated)
• Inventors: Wigström, Fredrik, Ingemarsson, Anders
• Granted Patent: US 7,140,641 B2
• Time in Patent Office: Days
• US Class Current: 280/806
• CPC Class Codes: B60R 2021/01272 Belt tensioners
• CPC Class Codes: B60R 2021/01279 Load limiters
• CPC Class Codes: B60R 2022/288 with means to adjust or regulate the amount of energy to be absorbed
• CPC Class Codes: B60R 2022/289 Energy-absorption curves
• CPC Class Codes: B60R 2022/4825 for sensing amount of belt winded on retractor
• CPC Class Codes: B60R 2022/4858 for sensing pressure on seat
• CPC Class Codes: B60R 21/0134 responsive to imminent contact with an obstacle , e.g. using radar systems
• CPC Class Codes: B60R 21/01532 using electric or capacitive field sensors
• CPC Class Codes: B60R 22/341 comprising energy-absorbing means

Abstract

A safety-belt arrangement for use in a motor vehicle has a safety-belt (5), one end of which is connected to a retractor (8), a sensor (11) generates a signal representative of the amount of safety-belt paid-out from the retractor. A force limiter (10) is associated with the retractor to permit safety-belt to be paid-out with a variable force limiting effect. A control arrangement (12) changes the level of force applied by the force limiter (10) in dependence upon the length of safety-belt paid-out from the retractor.

Claims

1. A safety-belt arrangement for use in a motor vehicle, the safety-belt arrangement comprising a safety-belt, one end of which is connected to a retractor, a sensor adapted to generate a signal representative of the amount of the safety-belt paid-out from the retractor, a force limiter associated with the retractor adapted to permit the safety-belt to be paid-out with a variable force limiting effect, means to change the level of force applied by the force limiter, and a control unit to receive a signal from the sensor and to generate, at least partially in response to said signal, an output signal to control the means which change the level of force.

2. An arrangement according to claim 1 wherein the retractor incorporates a pretensioner.

3. An arrangement according to claim 2 wherein the control unit generates said output signal in response to the amount of safety-belt paid-out in excess of the amount of webbing paid-out prior to activation of the pretensioner.

4. An arrangement according to claim 2 wherein the control unit generates said output signal in response to the amount of safety-belt paid-out in excess of the amount of safety-belt paid-out immediately after the pretensioner has been activated.

5. An arrangement according to claim 2 wherein means are provided to lock the safety-belt in response to a sensed parameter and wherein the control unit generates said output signal at least partly in response to a predetermined amount of safety-belt being paid-out in excess of a reference length, means being provided to determine the reference length at or shortly after the instant of locking of the safety-belt.

6. An arrangement according to claim 5 wherein a crash detector is provided and the means to determine the reference length are adapted to be actuated a predetermined period of time after the crash detector detects the crash.

7. An arrangement according to claim 6 wherein the predetermined period is 20 to 30 ms.

8. An arrangement according to claim 7 wherein the period is 20 ms.

9. An arrangement according to any one of claims 5 to 8 wherein the control unit is adapted to generate the control signal a predetermined period of time after the predetermined amount of safety-belt has been paid out.

10. An arrangement according to claim 9 wherein means are provided to select the predetermined period of time and the predetermined amount of safety-belt in response to a signal indicative of the severity of the crash.

11. An arrangement according to any one of the preceding claims wherein a further sensor is provided to generate a signal representative of a parameter of the occupant, which signal is supplied to the control unit, the output signal of the control unit also being related to the signal from the second sensor.

12. An arrangement according to claim 11 wherein the further sensor determines the weight of the occupant of the seat.

13. An arrangement according to claim 11 wherein the further sensor is a capacitative sensor adapted to determine the water content of the occupant of the seat.

14. An arrangement according to claim 11 wherein the further sensor is an optical sensor adapted to determine a size parameter of the occupant of the seat.

15. An arrangement according to any one of claims 11 to 14 wherein the control unit is adapted to categorise an occupant, in response to the signal representative of a parameter, into one of a plurality of categories, the length of safety-belt necessary to be withdrawn to cause the change in the force limiting effect being dependent upon the category of the occupant of the seat.

16. An arrangement according to any one of the preceding claims wherein the said variable force limiting effect comprises a plurality of discrete force levels.

17. An arrangement according to claim 16 wherein the force levels comprise two discrete force levels.

18. An arrangement according to any one of the preceding claims wherein a crash sensor is provided adapted to generate a signal representative of the crash severity, and the force limiting effect is adjusted to be a function of crash severity.