Steering column assembly for a vehicle

1 . A steering column assembly for a vehicle, comprising:

a steering column mounted for rotation about a longitudinal axis extending through the steering column, wherein the steering column is configured for attachment to a steering wheel at one end;

a first gear connected to the steering column at a location spaced from a portion of the steering wheel where the steering wheel is attached, the first gear configured to rotate with the steering column;

first and second motors;

first and second worm screws connected to and rotatable with an output of the first and second motors respectively and engaged with the first gear; and

a control arrangement configured to operate the first and second motors;

wherein rotational axes of the first and second worm screws are inclined with respect to a plane extending perpendicular to the rotational axis of the steering column; and

wherein the rotational axes of the worm screws are oriented substantially vertically in normal use.

2 . A steering column assembly as claimed in claim 1 , wherein the first gear is connected to the steering column at an opposite end of the steering column from the steering wheel.

3 . A steering column assembly as claimed in claim 1 , wherein the rotational axes of the first and second worm screws are inclined at substantially the same angle.

4 . A steering column assembly as claimed in claim 1 , wherein the first and second worm screws have the same helix angle.

5 . A steering column assembly as claimed in claim 4 , wherein the first and second worm screws are oppositely-handed.

6 . A steering column assembly as claimed in claim 4 , wherein the rotational axes of the first and second worm screws are inclined at substantially the same angle as the helix angle of the worm screws.

7 . A steering column assembly as claimed in claim 1 , wherein the rotational axes of the worm screws are parallel.

8 . A steering column assembly as claimed in claim 1 , wherein the worm screws are positioned on opposite sides of the rotational axis of the first gear.

9 . A steering column assembly as claimed in claim 8 , wherein the worm screws are positioned at diametrically opposite sides of the rotational axis of the first gear.

10 . A steering column assembly as claimed in claim 1 , wherein the first gear is a straight-cut gear.

11 . A steering column assembly as claimed in claim 1 , wherein the rotational axes of the first and second worm screws are inclined towards a same side of a plane extending perpendicular to the rotational axis of the steering column.

12 . A steering column assembly as claimed in claim 11 , wherein ends of the first and second worm screws remote from the respective motors are inclined towards the end of the steering column configured for attachment to the steering wheel.

13 . A steering column assembly as claimed in claim 1 , wherein the first and second motors are positioned below the first and second worm screws respectively.

14 . A steering column assembly as claimed in claim 1 , wherein the outputs of the first and second motors are connected directly to the first and second worm screws respectively.

15 . A steering column assembly as claimed in claim 14 , further comprising a circuit board located between the worm screws and their respective motor and wherein the outputs of each of the first and second motors passes through an aperture in the circuit board.

16 . A steering column assembly as claimed in claim 15 , wherein the circuit board comprises a motor output position sensor for each of the first and second motors.

17 . A steering column assembly as claimed in claim 16 , wherein each of the motor output position sensor are located adjacent to the respective aperture through which the respective output of one of the motors passes.

18 . A steering column assembly as claimed in claim 17 , wherein each motor output position sensor is annular and the output of each of the first and second motors passes through the respective motor output position sensor.

19 . A steering column assembly as claimed in claim 16 , wherein the output of each of the first and second motors carries a magnet which interacts with the respective motor output position sensor.

20 . A vehicle comprising a steering column assembly as claimed in claim 1 .

21 . A vehicle as claimed in claim 20 , wherein the longitudinal axis of the steering column is inclined to the horizontal.

22 . A steering column assembly for a vehicle, comprising:

a housing,

a shaft rotatably mounted with respect to the housing and configured for attachment of a steering wheel at one end,

a first gear connected to and configured to rotate with the shaft,

first and second motors, each having an output driving a respective output gear, the output gears being engaged with the first gear, and

a control arrangement configured to operate the motors,

wherein:

the first gear comprises a worm gear and each output gear comprises a worm screw,

the worm screws are positioned on opposite sides of the rotational axis of the shaft,

the rotational axes of the worm screws are each inclined at an angle to a plane extending perpendicularly to the rotational axis of the shaft, and are inclined toward the same side of that plane;

wherein the ends of the worm screws remote from the motors are inclined toward a steering wheel end of the shaft;

the first and second worm screws have opposite-handed threads, and

a circuit board is located between the worm screws and the motors, each motor output passes through a respective aperture in the circuit board, and each of the outputs carries an annular motor output position sensor through which the motor output passes.