GB2263756A

GB2263756A - Adjustment mechanism for vehicle steering columns.

Info

Publication number: GB2263756A
Application number: GB9201533A
Authority: GB
Inventors: William Carl Baskett
Original assignee: Ford Motor Co
Current assignee: Ford Motor Co
Priority date: 1992-01-24
Filing date: 1992-01-24
Publication date: 1993-08-04
Also published as: GB9201533D0

Abstract

The steering column (2) is adjusted for length and rake by a single lever operated locking member (11, 21) which passes through the legs (6, 7) of a bridging bracket (3) connected to the frame of the vehicle, and which passes through a bracket (1) connected to the steering column (2). The legs (6, 7) and the bracket (1) are provided with furrowed slots (4, 5 and 8) which cooperate with rollers (19, 20) located in slots (17, 18) in a tubular moulding (11) which extends through slot (4), channel (8) and slot (5). A profiled rod (21) inside the bore (22) of the moulding (11) has cam facets (27, 28, 29) aligned with the slots (17, 18) so that rotation of the rod (21) by the handle (23) causes the rollers (19, 20) to engage or disengage the slots (17, 18) to permit locking or unlocking of the adjustment mechanism. <IMAGE>

Description

Title: Adjustment Mechanism for Steering Columns Field of the Invention: The present invention relates to an adjustment mechanism for a steering column. The invention particularly relates to steering columns for cars and similar light motor vehicles.

Background to the Invention: Generally, motor vehicles have steering columns which may be adjusted in length and rake angle to allow for seat adjustment and driver comfort. Such adjustment mechanisms ensure that the transmission of rotational movement of the steering wheel is not impeded or prevented regardless of the positioning of the steering column.

The adjustment of such mechanisms generally require two distinct adjustment activities so that each adjustment is made in turn. Such arrangements generally require unconnected adjustment mechanisms each of which is actuated by its own lever or locking mechanism.

Locking mechanisms are known in which a cam engages with a roller or ball to locate with a slot or flutes to position one part of the mechanism relative to another. Such mechanisms are disclosed in EP Patent Specification 179 711 relating to telescopic couplings and also in GB Patent Specification 1600557.

The present invention seeks to provide an adjustment mechanism in which a single lever releases the locking mechanism so that the length and rake angle may be simultaneously adjusted and locked in the desired position by operation of the single lever.

Summarv of the Invention: According to the present invention there is provided an adjustment mechanism for a steering column in which a single locking means is provided for the adjustment mechanism which is capable of adjustment about two orthogonal axis one of which is aligned with the axis of the steering column.

Preferably, the adjustment mechanism may be adjusted within a series of discrete positions about each of the two orthogonal axis. The series of positions may be equal in number and pitch in each of the orthogonal directions although it is generally preferable to provide greater adjustment of the position of the steering wheel aligned with the axis of the steering column rather than the rake angle of the steering column.

Brief Description of the Drawings: The invention will now be described by way of example with reference to the accompanying diagrammatic drawings in which:- Figure 1 shows an exploded view of the adjustment mechanism; Figure 2 shows the locking mechanism in the locked position; and Figure 3 shows the locking mechanism in the unlocked position.

Specific Description of the Invention: Referring now to the drawing, figure 1 illustrate an exploded view of the adjustment mechanism. The mechanism consists of four basic parts. A bracket 1 is firmly connected to the steering column 2 on which the steering wheel (not shown) is mounted. A saddle shaped bracket 3 which in use, fits over the bracket 1 so that corrugated slots 4 and 5 in legs 6 and 7 respectively align with a corrugated channel 8 in the bracket 1. The bracket 3 is provided with fixing holes 9 and 10 through which bolts fix the bracket 3 to the frame or chassis of the vehicle.

A tubular plastic moulding 11 passes through the slot 4, the channel 8 and the slot 5. One end of the moulding 11 is provided with a groove 12 which co-operates with a circlip 13 to maintain moulding in position between the legs 6 and 7. The other end of the moulding 11 is provided with a shaped head 14 which is recessed on the face 15 so that it fits against the leg 6 and is prevented from rotating by the arms 16. The moulding 11 is provided with diametrically opposed slots 17 and diametrically opposed slots 18. The diameter line of the slots 17 is ortogonal to the diameter line of slots 18. Rollers 19 are provid and rollers 20 in the slots 18 so that the moulding 11 acts as a cage for the rollers when actuated by a profiled rod 21 which passes through the bore 22 of the moulding 11.A lever 23 is fixed to one end of the rod 21 and circlip 24 co-operates with a groove 25 and the end face 26 of the moulding 11 to hold the rod in place with cam facets 27, 28 and 29 aligned with the slots 17 and 18.

Referring now to figures 2 and 3, in use, the rollers 19 engage with grooves in the corrugated slots 4 and 6 and in the channel 8 to lock the bracket 1 in position.

Figure 2 shows a cross section through the mechanism aligned with the slot 18 and the cam facet 28. The mechanism is in the locked position with the rollers 19 engaging a set of opposed grooves in the corrugated channel 8. Because the rollers 19 are held in place by the rod 21 the mechanism is locked against movement in the direction of the arrows A.

If telescopic adjustment of the steering wheel is required the mechanism may be unlocked as shown in figure 3. As shown in figure 3, the rod 21 is rotated through 90 by means of the lever 23 (shown in figure 1) so that the rollers 19 disengage the grooves and lay within the slots 18 against the facets 28. In this position the mechanism may be adjusted in the direction of the arrows A and locked in a suitable position by operation of the lever 23 through 90 so that the rollers 19 reengage opposed grooves in the channel 8 (as shown in figure 2).

It will be appreciated that when the lever 23 is moved through 90 the rollers 19 in slots 17 are allowed to disengage the grooves in the corrugated slots 4 and 6 so permitting simultaneous vertical adjustment of the steering column.

Therefore by operation of the single lever 23 both the telescopic and rake angle of the column may be released, adjusted and relocked in position.

Although the embodiment has been described with the two directions of adjustment set at 90 with respect to each other the alignment of the axes of adjustment may be at other angles more or less than 90 according to the specific design required for each type of vehicle steering column.

Such range of alignment is referred to in the specification as "orthogonal".

Claims

Claims:

1 An adjustment mechanism for a steering column in which a single locking means is provided for the adjustment mechanism which is capable of adjustment about two orthogonal axis one of which is aligned with the axis of the steering column.

2 An adjustment mechanism as claimed in claim 1 in which the adjustment is made in discrete steps.

3 An adjustment mechanism as claimed in claim 2 in which the discrete steps are equal in pitch in both orthogonal directions.

4 An adjustment mechanism as claimed in Claim 2 or Claim 3 in which the number of discrete step adjustments aligned with the axis of the steering column is greater than the orthogonal rake axis.

5 An adjustment mechanism as claimed in any preceding claim in which the single locking means includes first cam actuated rollers engaging with a first set of furrows in a co-operating member connected to the steering column and second cam actuated rollers engaging with a second set of furrows in a co-operating connected to the frame of the vehicle.

6 An adjustment mechanism as claimed in claim 5 in which the first set of furrows comprises two opposed rows of furrows within a slotted bracket member through which the locking means passes.

7 An adjustment mechanism as claimed z the second set of furrows comprises two pairs of opposed in legs of a bracket member which bridges the slotted member.

8 An adjustment mechanism substantially as hereinbefore described with reference to the accompanying drawings.