Variable energy-absorbing steering column

• US 6,170,874 B1
• Filed: 05/19/1999
• Issued: 01/09/2001
• Est. Priority Date: 11/21/1996
• Status: Expired due to Term

• Current Assignee: AB Volvo
• Original Assignee: AB Volvo
• Inventors: Fosse, Tore
• Primary Examiner(s): English, Peter C.
• Application Number:
  US09/308,432
• Time in Patent Office: 601 Days
• Field of Search: 280/777, 180/268, 744/92, 188/371
• US Class Current: 280/777
• CPC Class Codes: B62D 1/195 Yieldable supports for the steering column

Abstract

Apparatus and methods for protecting the occupant of a motor vehicle including a seat belt for restraining the occupant and a stress-bearing structure are disclosed. The apparatus includes a steering shaft, a steering column supporting the steering shaft, the steering column displaceably mounted with respect to the stress-bearing structure, a first energy absorber for absorbing energy upon displacement of the steering column with respect to the stress-bearing structure by the occupant, a sensor for detecting a condition in which the occupant is restrained by the seat belt, a second energy absorber for absorbing energy upon displacement of the steering column with respect to the stress-bearing structure by the occupant, and a lock for permitting absorption of energy by the second energy-absorbing unit by displacement of the steering column with respect to the stress-bearing structure by the occupant when the condition is detected by the sensor.

Claims

1. Apparatus for protecting the occupant of a motor vehicle including a seatbelt for restraining said occupant and a stress-bearing structure, said apparatus comprising a steering shaft, a steering column supporting said steering shaft, said steering column displaceably mounted with respect to said stress-bearing structure, a first energy-absorbing unit for absorbing energy upon displacement of said steering column with respect to said stress-bearing structure by said occupant, a sensor for detecting a condition in which said occupant is restrained by said seatbelt, a second energy-absorbing unit for absorbing energy upon displacement of said steering column with respect to said stress-bearing structure by said occupant, and a locking member for permitting said absorption of energy by said second energy-absorbing unit by displacement of said steering column with respect to said stress-bearing structure by said occupant when said condition is detected by said sensor.

2. The apparatus of claim 1 wherein said locking member prevents absorption of energy by said second energy-absorbing unit by displacement of said steering column with respect to said stress-bearing structure by said occupant when said condition is not detected by said sensor.

3. The apparatus of claim 1 wherein the energy capable of being absorbed by said first energy-absorbing unit is less than the energy capable of being absorbed by said second energy-absorbing unit.

4. The apparatus of claim 1 wherein said second energy-absorbing unit comprises a first carriage fixedly mounted with respect to said steering column, a second carriage fixedly mounted with respect to said stress-bearing structure, said first and second carriages being displaceably mounted with respect to each other, and a second energy-absorbing element for absorption of said energy upon displacement of said first carriage with respect to said second carriage.

5. The apparatus of claim 4 wherein said locking member comprises an electrically operated solenoid.

6. The apparatus of claim 5 wherein said electrically operated solenoid is mounted on one of said first and second carriages, said electrically operated solenoid including a piston, and wherein the other of said first and second carriages includes a recess cooperating with said piston.

7. The apparatus of claim 6 wherein said electrically operated solenoid is mounted on said second carriage and said other of said first and second carriages comprises said first carriage.

8. The apparatus of claim 4 wherein said second energy-absorbing element comprises a strip including a first end and a second end, said first end of said strip being affixed to said first carriage and said second end of said strip being affixed to said second carriage.

9. A method for protecting the occupant of a motor vehicle including a seatbelt for restraining said occupant, a stress-bearing structure, a steering shaft, and a steering column supporting said steering shaft, said steering column being displaceably mounted with respect to said stress-bearing structure, said method comprising detecting a condition in which said occupant is restrained by said seatbelt, absorbing energy through a first energy-absorbing unit upon displacement of said steering column with respect to said stress-bearing structure by said occupant, and absorbing energy through a second energy-absorbing unit upon displacement of said steering column with respect to said stress-bearing structure when said condition is detected.

10. The method of claim 9 including preventing absorption of said energy by said second energy-absorbing unit by displacement of said steering column with respect to said stress-bearing structure by said occupant when said condition is not detected.

11. The method of claim 9 wherein the energy capable of being absorbed by said first energy-absorbing unit is less than the energy capable of being absorbed by said second energy-absorbing unit.

12. The method of claim 10 wherein said second energy-absorbing unit includes a locking member having a first actuated condition for permitting said absorption of energy by said second energy-absorbing unit, and a second non-actuated condition for preventing said absorption of energy by said second energy-absorbing unit, whereby said locking member is actuated when said condition is detected, said method including feeding a current to an electrically operated solenoid for actuating said locking member.

13. The method of claim 9 wherein a second carriage is affixed to said stress-bearing structure, and a first carriage is affixed to said steering column, said first and second carriages being displaceably affixed to each other, said absorbing of said energy through said second energy-absorbing unit comprising displacement of said first carriage with respect to said second carriage.