Steering column assembly

Patent metadata

Field	Value
Publication number	US-10654513-B2
Application number	US-201716087132-A
Country	US
Kind code	B2
Filing date	Mar 23, 2017
Priority date	Mar 23, 2016
Publication date	May 19, 2020
Grant date	May 19, 2020

Abstract

A steering column assembly comprises a telescopic shroud having an outer shroud portion and an inner shroud portion, a clamp rail fixed to an upper face of the inner shroud portion including a slot, a clamp bolt that extends perpendicular to the shroud, a rocker comprising a body from which extends a lever arm, the body having an opening through which the clamp bolt passes, the rocker converting a rotation of the clamp bolt about its axis in a first direction into an upward motion of the lever arm and into a downward motion when the clamp bolt is rotated in the opposing second direction, a toothed block having two opposed racks of locking teeth that is connected to a carrier element, the carrier element in turn being connected to the lever of the rocker arm such that movement of the lever arm up and down causes movement of the carrier element up and down between an upper position and a lower position. When the carrier element is in one of the upper position and the lower position, the toothed block is located within the slot such that one of the rows of teeth of the block engages a row of teeth of the slot, and whereby, with the carrier element in the other of the upper position and the lower position, the teeth of toothed block are held clear of the slot, and in which the connection between the clamp bolt and the carrier defines a lost motion mechanism that prevents some of the rotational movement of the clamp bolt from being converted into movement of the toothed block.

First claim

The invention claimed is:

1. A steering column assembly comprising:
a telescopic shroud having an outer shroud portion and an inner shroud portion, an end of the inner shroud portion extending into the outer shroud portion,
a clamp rail fixed to an upper face of the inner shroud portion including a slot that extends axially along the inner shroud portion, the slot defining two opposing walls which each carry a rack of locking teeth,
a clamp bolt that extends perpendicular to the telescopic shroud that is configured to be rotated around a long axis thereof by operation of a locking lever,
a rocker comprising a body from which extends a lever arm, the body having an opening through which the clamp bolt passes, the rocker converting a rotation of the clamp bolt about the long axis in a first direction into an upward motion of the lever arm and into a downward motion when the clamp bolt is rotated in an opposing second direction,
a toothed block having two opposed racks of locking teeth that is connected to a carrier element, the carrier element in turn being connected to the lever arm of the rocker such that movement of the lever arm up and down causes movement of the carrier element up and down between an upper position and a lower position,
whereby, with the carrier element in one of the upper position and the lower position, the toothed block is located within the slot such that one of the two opposed racks of locking teeth of the toothed block engages the locking teeth of the slot, and whereby, with the carrier element is the other of the upper position and the lower position, the two opposed racks of locking teeth of toothed block are held clear of the slot, and
in which the connection between the clamp bolt and the carrier element defines a lost motion mechanism that prevents some of the rotational movement of the clamp bolt from being converted into movement of the toothed block.

2. The steering column assembly as claimed in claim 1 , wherein the lost motion mechanism permits an angular movement of the clamp bolt of at least 20 degrees, whilst achieving a linear movement of the toothed block between raised and lowered conditions of less than 20 mm.

3. The steering column assembly as claimed in claim 1 , wherein the lost motion mechanism provides for rotational lost motion between the clamp bolt and the rocker.

4. The steering column assembly as claimed in claim 1 , wherein the lost motion mechanism is arranged to lose up to 5 degrees, of angular movement of the clamp bolt at a first/last/intermediate stage of a clamping/unclamping thereof.

5. The steering column assembly as claimed in claim 1 , wherein the lost motion mechanism provides for linear lost motion between the rocker and the carrier element.

6. The steering column assembly as claimed in claim 1 , wherein the lost motion mechanism is provided by free play between the opening in the rocker and a shape of a corresponding portion of the clamp bolt, such that the free play has to be taken up by an amount of rotation of the clamp bolt before the clamp bolt acts upon the rocker.

7. The steering column assembly as claimed in claim 6 , wherein the corresponding portion of the clamp bolt comprises a non-circular cross section, the opening of the rocker also being non-circular in cross-section.

8. The steering column assembly as claimed in claim 1 , wherein the lever arm of the rocker is connected to the carrier element through a further lost motion mechanism.

9. The steering column assembly as claimed in claim 1 , wherein the carrier element comprises a rigid block including an opening in which the lever arm is located.

10. The steering column assembly as claimed in claim 8 , wherein the opening in the carrier element is oversized to provide some lost motion.

11. The steering column assembly as claimed in claim 9 , further comprising a spring which acts between the lever arm and the carrier element or the lever arm and the toothed body, the spring being compressed by the rocker arm as the toothed block engages the locking teeth of the slot, to provide some lost motion.

12. The steering column assembly as claimed in claim 10 , wherein the lever arm is bounded on one side by the spring and on the other side by a portion of the carrier element, a width of the opening being greater than a width of the rocker arm within the opening so as to provide some additional lost motion in addition to the lost motion provided by compression of the spring.

13. The steering column assembly as claimed in claim 11 , wherein the spring is arranged to be compressed as the lever arm of the rocker approached a lowest position thereof such that the spring applies a compressive force between the toothed block and a lever arm, when clamped.

14. The steering column assembly as claimed in claim 11 , wherein the spring is a leaf spring.

15. The steering column assembly as claimed in claim 14 , wherein the leaf spring is a bent metal or composite strap that is secured to the carrier element.

16. The steering column assembly as claimed in claim 1 , wherein the carrier element is free to move from side to side to permit the toothed block to move from side to side within the slot.

17. The steering column assembly as claimed in claim 1 , wherein the carrier element is connected to the toothed block by a connecting pin.

18. The steering column assembly as claimed in claim 17 , wherein the connecting pin is frangible such that a crash load as expected during a crash will cause the connecting pin to break, permitting the block to move freely relative to the carrier element.

19. The steering column assembly as claimed in claim 1 , wherein the lost motion mechanism is arranged to lose up to 10 degrees, of angular movement of the clamp bolt at a first/last/intermediate stage of a clamping/unclamping thereof.

20. The steering column assembly as claimed in claim 1 , wherein the lost motion mechanism is arranged to lose up to 20 degrees, of angular movement of the clamp bolt at a first/last/intermediate stage of a clamping/unclamping thereof.

Assignees

• Trw Ltd
• Trw Automotive Gmbh

Inventors

• Dite Jan
• Davies Niclas
• Lingemann Markus

Classifications

• B62D1/184 Primary

  Mechanisms for locking columns at selected positions · CPC title

• B62D1/185

  adjustable by axial displacement, e.g. telescopically (B62D1/183, B62D1/187, B62D1/19 take precedence) · CPC title

• B62D1/195

  Yieldable supports for the steering column · CPC title