Steering column assembly

Patent metadata

Field	Value
Publication number	US-11014595-B2
Application number	US-201816487560-A
Country	US
Kind code	B2
Filing date	Feb 23, 2018
Priority date	Feb 23, 2017
Publication date	May 25, 2021
Grant date	May 25, 2021

Abstract

A steering column assembly comprises a shroud having an upper shroud part and a lower shroud part movable telescopically relative to one another, and a steering shaft. The upper shroud part carries an energy absorbing device which in normal use moves together with the upper shroud part. A blocking device is fixed to the lower shroud part or to a part of the vehicle that is fixed relative to the lower shroud part; and a connecting rod is connected at a first end to the blocking device and at a second end to a spring which is in turn connected to the lower shroud part or to the fixed part of the vehicle. An initiator module engages with a part of the connecting rod or spring when the blocking mechanism is in the unlocked position thereby to isolate the blocking device from the force of the spring.

First claim

The invention claimed is:

1. A steering column assembly comprising:
a shroud having an upper shroud part located towards an end of the column assembly nearest a steering wheel, and a lower shroud part located at an end of the column assembly furthest from the steering wheel, the two parts being movable telescopically relative to one another in the event of a crash to shorten the overall length of the shroud, a steering shaft that is supported by the shroud, and
the upper shroud part carrying an energy absorbing device which in normal use moves together with the upper shroud part,
characterised by further comprising a blocking mechanism that comprises:
a blocking device fixed to the lower shroud part or to a part of the vehicle that is fixed relative to the lower shroud part;
a connecting rod connected at a first end to the blocking device and at a second end to a spring which is in turn connected to the lower shroud part or to the fixed part of the vehicle,
an initiator module which engages with a part of the connecting rod or spring when the blocking mechanism is in the unlocked position thereby locating the connecting bar in a fixed position whereby the blocking device is substantially isolated from the force of the spring and is held clear of energy absorbing device, the initiator module holding the spring under compression or in tension,
and in which, in the locked position, the initiator module moves clear of the connecting rod whereby the force stored in the spring is released, causing the spring to move the connecting rod in turn to move the blocking device into positive engagement with the energy absorbing mechanism carried by the upper shroud portion.

2. The steering column assembly according to claim 1 , wherein the connecting rod includes a recess or hole or protrusion which receives or engages the initiator module.

3. The steering column assembly according to claim 1 , wherein the connecting rod comprises an elongate wire.

4. The steering column assembly according to claim 3 , wherein the elongate wire is rigid.

5. The steering column assembly according to claim 3 , wherein the wire includes a full or partial loop which defines a boundary of a space which receives the part of the initiator module and from which the initiator module is withdrawn when the locking mechanism is unlocked.

6. A steering column assembly according to claim 5 , wherein the loop is located close to the end of the connecting rod which is connected to the spring.

7. A steering column assembly according to claim 3 , wherein the wire includes a hook portion on the end of the wire that extends orthogonally to the axis of the shroud and is received in a bore in the blocking device to connect the connecting rod to the blocking device.

8. A steering column assembly according to claim 7 , wherein the spring comprises a helical spring.

9. A steering column assembly according to claim 8 , wherein the helical spring comprises a coiled elongate wire.

10. A steering column assembly according to claim 9 , wherein the helical spring is integrally formed with the connecting rod.

11. A steering column assembly according to claim 10 , wherein the spring, in the locking position, is held in tension by the connecting rod, which is, in turn, fixed by the part of the initiator module, and when in the unlocked position the spring relaxes to reduce the length of the spring thereby pulling on the connecting rod to move the blocking device.

12. A steering column assembly according to claim 1 , wherein the spring, in the locking position, is held in compression by the initiator module, and when in the unlocked position the spring relaxes to push the connecting rod to move the blocking device.

13. A steering column assembly according to claim 1 , wherein the blocking device of the blocking mechanism comprises a cam element connected to the connecting rod so that the motion of the connecting rod is converted into a rotary motion of the cam element.

14. A steering column assembly according to claim 13 , wherein the cam element comprises at least one engagement tooth carried by a base portion, the base portion being connected to the lower shroud portion or to the fixed part of the vehicle through a pivot, movement of the cam element being achieved by rotation when acted on by the connecting rod, the tooth being held clear of the upper shroud part when the blocking mechanism is in the unlocked condition and engaging when locked.

15. A steering column assembly according to claim 14 , wherein the tooth is formed on an outer edge of the base portion of the cam element.

16. A steering column assembly according to claim 14 , wherein the cam element includes a plurality of engagement teeth, with more than one tooth engaging the energy absorbing device of the upper shroud part when in the locked position.

17. A steering column assembly according to claim 14 , wherein the movement of the cam between the unlocked and locked position may be such that the teeth rotate in a direction with a component that extends away from the steering wheel end of the steering column assembly.

18. A steering column assembly according to claim 17 , wherein the cam element is located closer to the steering wheel end of the steering column assembly than the spring with the spring pulling on the cam element away from the steering wheel.

19. A steering column assembly according to claim 14 , wherein the energy absorbing mechanism carried by the upper shroud portion comprises a sliding block, the cam element engaging the sliding block when the lock mechanism is in the locked position and being held clear of the toothed rack when the lock mechanism is in the unlocked position.

20. A steering column assembly according to claim 19 wherein the sliding block carries a rack of teeth and the cam element also includes teeth that engage the teeth of the rack in the locked position.

Assignees

• Trw Ltd
• Zf Automotive Uk Ltd

Inventors

• Davies Niclas

Classifications

• B62D1/195

  Yieldable supports for the steering column · CPC title

• B62D1/184 Primary

  Mechanisms for locking columns at selected positions · CPC title

• B62D1/192 Primary

  Yieldable or collapsible columns · CPC title

• B62D1/185

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

• F16C2326/24

  Steering systems, e.g. steering rods or columns · CPC title