Travel limiter for a vehicle steering column

Patent metadata

Field	Value
Publication number	US-11808325-B2
Application number	US-202217587927-A
Country	US
Kind code	B2
Filing date	Jan 28, 2022
Priority date	Jan 29, 2021
Publication date	Nov 7, 2023
Grant date	Nov 7, 2023

Abstract

A travel limiter for a rotatable steering column of a vehicle comprises: a housing; an elongate threaded member rotatably mounted about its longitudinal axis within the housing; a nut member threadedly mounted on the elongate threaded member, the exterior of the nut member comprising a toothed gear; connector for connection of a rotatable steering column of a vehicle to the elongate threaded member, whereby the steering column and the threaded member are constrained to rotate together; end stops which engage with the nut member to define the maximum axial displacement of the nut member along the elongate threaded member in both directions; a drive motor having an output shaft configured to rotate an output gear member meshed with the gear on the exterior of the nut member; and a controller configured to control the operation of the drive motor.

First claim

The invention claimed is:

1. A travel limiter for a rotatable steering column of a vehicle, comprising:
a housing;
an elongate threaded member rotatably mounted about its longitudinal axis within the housing;
a nut member threadedly mounted on the elongate threaded member, an exterior of the nut member comprising a toothed gear;
a connector for connection of the rotatable steering column of the vehicle to the elongate threaded member, whereby the steering column and the threaded member are constrained to rotate together;
end stops which engage with the nut member to define a maximum axial displacement of the nut member along the elongate threaded member in both directions;
a drive motor having an output shaft configured to rotate an output gear member meshed with the gear on the exterior of the nut member; and
a controller that operates to control the operation of the drive motor.

2. The travel limiter as claimed in claim 1 , wherein the end stops comprise a clutch or brake.

3. The travel limiter as claimed in claim 2 , wherein each clutch or brake comprises a plurality of plates.

4. The travel limiter as claimed in claim 2 , wherein each clutch or brake comprises a first plate mounted on a first plate carrier located within the housing, the first plate being engageable with a second plate mounted on a second plate carrier configured to rotate with the elongate threaded member.

5. The travel limiter as claimed in claim 2 , wherein each clutch or brake comprises a plurality of plates mounted on the first plate carrier and a plurality of plates mounted on the second plate carrier, the plates on the first and second carriers being interleaved.

6. The travel limiter as claimed in claim 4 , wherein the first plate carriers of the clutch or brake are displaceable with respect to the housing.

7. The travel limiter as claimed in claim 6 , wherein the first plate carriers of the clutch or brake are displaceable with respect to the housing in a direction parallel to the longitudinal axis of the elongate threaded member.

8. The travel limiter as claimed in claim 7 , comprising a biasing arrangement for biasing the first plate carriers of the clutch or brake away from each other.

9. The travel limiter as claimed in claim 8 , wherein the biasing arrangement comprises one or more springs for biasing the first plate carriers of the clutch or brake away from each other.

10. The travel limiter as claimed in claim 4 , further comprising a ratchet arrangement which permits rotation of each of the first plate carriers with respect to the housing in one direction and which inhibits rotation of each of the first plate carriers with respect to the housing in the opposite direction.

11. The travel limiter as claimed in claim 10 , wherein each of the first plate carriers comprises a plurality of ratchet teeth engaged with ratchet teeth which are fixed with respect to the housing.

12. The travel limiter as claimed in claim 1 , further comprising an engagement mechanism which permits rotation of each of the first plate carriers with respect to the housing through a predetermined angle.

13. The travel limiter as claimed in claim 12 , wherein the engagement mechanism comprises a projection engaged in a slot.

14. The travel limiter as claimed in claim 12 , wherein the engagement mechanism comprises a plurality of projections fixed with respect to the housing, each of which is received in a respective slot in one of the first plate carriers.

15. The travel limiter as claimed in claim 1 , wherein the teeth of the gear on the exterior of the nut member are straight cut and are aligned with the longitudinal axis of the elongate threaded member.

16. The travel limiter as claimed in claim 15 , wherein the output gear member rotated by the drive motor comprises a worm screw.

17. The travel limiter as claimed in claim 16 , wherein a rotational axis of the worm screw is inclined respect to the teeth of the gear on the exterior of the nut member by the same angle as a helix angle of the worm screw.

18. The travel limiter as claimed in claim 1 , wherein the engagement of the output gear member with the gear on the exterior of the nut member is non-reversible.

19. The travel limiter as claimed in claim 1 , wherein the engagement of the output gear member with the gear on the exterior of the nut member is reversible.

20. The travel limiter as claimed in claim 1 , further comprising a first and second spring, which apply a longitudinal force on the nut member in opposite directions to each other.

21. The travel limiter as claimed in claim 20 , wherein the first and second spring comprise helical springs through which the elongate threaded member passes.

22. The travel limiter as claimed in claim 1 , wherein the elongate threaded member is tubular.

23. The travel limiter as claimed in claim 22 , wherein the tubular threaded member comprises a key for engagement with a complementarily-shaped portion of the steering column.

24. The travel limiter as claimed in claim 23 , wherein the tubular threaded member comprises an internally splined portion for engagement with a complementarily splined portion of the steering column.

Assignees

• Zf Automotive Uk Ltd

Inventors

• Wilkes Mark Anthony
• Wilson-Jones Russell

Classifications

• F16H19/02 Primary

  for interconverting rotary {or oscillating} motion and reciprocating motion · CPC title

• B62D1/16

  Steering columns · CPC title

• B62D5/043

  characterised by clutch means between driving element, e.g. motor, and driven element, e.g. steering column or steering gear · CPC title

• B62D5/046

  Controlling the motor · CPC title

• B62D5/0409 Primary

  Electric motor acting on the steering column · CPC title