Adaptive collapsible steering column

• US 6,296,280 B1
• Filed: 11/02/1999
• Issued: 10/02/2001
• Est. Priority Date: 11/02/1999
• Status: Expired due to Fees

• Current Assignee: TRW Inc. (Northrop Grumman Corporation)
• Original Assignee: TRW Inc. (Northrop Grumman Corporation)
• Inventors: Faigle, Ernst M., Struble, Rex R.
• Primary Examiner(s): CULBRETH, ERIC D
• Application Number:
  US09/433,594
• Time in Patent Office: 700 Days
• Field of Search: 280/777, 280/779, 744/92
• US Class Current: 280/777
• CPC Class Codes: B62D 1/195 Yieldable supports for the steering column

Abstract

An apparatus for supporting a steering wheel (22) of a vehicle (10) comprises a first steering column part (32) and a second steering column part (34). The apparatus also comprises supporting structure (46) supporting the first steering column part (32) and the vehicle steering wheel (22) for movement relative to the second steering column part (34) along an axis (36) of the steering column (12). The apparatus further comprises an energy absorbing device (20) interposed between the first steering column part (32) and the second steering column part (34) for resisting movement of the first part relative to the second part. The energy absorbing device (20) comprises a fluid (50) having a shear strength which varies in response to an energy field acting on the fluid. The apparatus also includes means (54, 60) for varying the shear strength of the fluid (50) by varying the energy field to vary the resistance to movement of the first steering column part (32) relative to the second steering column part (34).

Claims

1. An apparatus for supporting a steering wheel of a vehicle, said apparatus comprising:

a first steering column part;

a second steering column part;

supporting structure supporting said first steering column part and the vehicle steering wheel for movement relative to said second steering column part along an axis;

an energy absorbing device interposed between said first steering column part and said second steering column part for resisting movement of said first part relative to said second part, said energy absorbing device comprising a fluid having a shear strength which varies in response to an energy field acting on said fluid; and

means for varying the shear strength of said fluid by varying said energy field to vary the resistance to movement of said first steering column part relative to said second steering column part.

2. An apparatus as set forth in claim 1 wherein said fluid is an electrorheological fluid whose shear strength varies in response to a change in voltage varying an electric field acting on said fluid.

3. An apparatus as set forth in claim 1 wherein said fluid is an electrorheological magnetic fluid whose shear strength varies in response to a change in magnetic field acting on said fluid.

4. An apparatus as set forth in claim 1 wherein said means for varying the shear strength of said fluid by varying said energy field comprises:

at least one vehicle condition sensor operative to sense a vehicle condition and to provide a first output signal;

at least one occupant condition sensor operative to sense an occupant condition and to provide a second output signal; and

a controller for receiving said first output signal and said second output signal and for, in response, controlling said energy field to control the resistance to movement of said first steering column part relative to said second steering column part.

5. An apparatus as set forth in claim 4 wherein said controller is operative to vary said energy field prior to onset of a vehicle crash condition and is operative to vary said energy field in response to conditions sensed after the onset of the vehicle crash condition.

6. An apparatus as set forth in claim 1 wherein said second steering column member comprises an annular capsule containing said fluid and said first steering column part comprises a member fixed for movement with the vehicle steering wheel and that extends through said capsule.

7. An apparatus as set forth in claim 6 wherein said means for varying the shear strength of said fluid comprises a coil extending around said capsule of fluid and a controller for controlling flow of electric current through said coil to vary said energy field.

8. An apparatus as set forth in claim 1 wherein said energy absorbing device comprises a shear capsule containing said fluid, a coil extending around said shear capsule and generating said energy field acting on said fluid, and a controller for controlling flow of electric current through said coil to vary said energy field.

9. An apparatus for supporting a steering wheel of a vehicle, said apparatus comprising:

a first steering column part;

a second steering column part;

supporting structure supporting said first steering column part and the vehicle steering wheel for movement relative to said second steering column part along an axis;

an energy absorbing device interposed between said first steering column part and said second steering column part for resisting movement of said first part relative to said second part, said energy absorbing device comprising a fluid having a shear strength which varies in response to an energy field acting on said fluid; and

means for varying the shear strength of said fluid by varying said energy field to vary the resistance to movement of said first steering column part relative to said second steering column part,

wherein said energy absorbing device comprises a shear bolt containing said fluid, and wherein said means for varying the shear strength of said fluid comprises a coil extending around said shear bolt and generating said energy field acting on said fluid, and a controller for controlling flow of electric current through said coil to vary said energy field.