ADJUSTABLE VEHICLE STEERING COLUMN CLAMPING MECHANISM

Abstract: An adjustable vehicle steering column clamping mechanism for a rake and reach adjustable steering column includes a steering column support bracket (3) which has two flanks (3A) extending on either side of a steering column outer tube (9), each flank (3A) incorporating a slot (3B) to permit rake adjustment. A reach adjustment bracket means (8) has two flanks (8A) which extend on either side of the tube (9) and lie adjacent the flanks (3B) of the bracket (3), the flanks (8A) also having slots (8B) extending parallel to the tube axis (9A) for reach adjustment. The flanks (8A) are spaced from the tube (9A) so as to accept heads (10A) of clamping bolts (10) operated by a handle (9) acting on associated clamping parts (12) mounted on the bolts (10). The arrangement enables the bolts to be located on a substantially on-centre line passing at right angles through the axis of the steering column.

Description: ADJUSTABLE VEHICLE STEERING COLUMN CLAMPING MECHANISM This invention relates to an adjustable vehicle steering column clamping mechanism. In known adjustable vehicle steering column clamping mechanisms, a steering column outer tube is supported in a bracket with slots in it to permit rake or vertical adjustment of the steering column and steering wheel and other slotted parts are provided to permit reach or axial adjustment of the steering column. In these known constructions, a clamping mechanism is provided with a clamping handle, the mechanism including a bolt rotatable by the clamping handle, the bolt extending between two flanks of the support bracket on either side of the steering column outer tube and the clamping mechanism clamp and release the steering column outer tube relative to the support bracket and the parts for reach adjustment. It will be appreciated that for the bolt to extend between the embracing flanks of the steering column outer tube, the bolt must pass either under or over the steering column outer tube, which therefore takes up space. In addition, in certain circumstances, uneven clamping effort is obtained with such an under or over arrangement of bolt clamping mechanism, with the bolt clamping pressure acting only from one side. According to the present invention, there is provided an adjustable vehicle steering column clamping mechanism including a steering column support bracket with two opposed slots therein and an adjustment bracket arranged to be joined to the steering column outer tube, the adjustment bracket having two slots positioned adjacent radially opposed portions of the steering column tube; there being a clamping mechanism operating handle having two bolt engaging portions, and bolts and associated clamping members on the bolts rotatable by said operating handle portions; characterised in that one bolt slidably engages one adjustment bracket slot, extending through one steering column support bracket slot and threadedly engaging one clamping mechanism operating handle bolt engaging portion, and the other bolt slidably engages the other adjustment bracket slot, extending through the other steering column support bracket slot and threadedly engaging the other clamping mechanism operating handle bolt engaging portion; the clamping mechanism operating handle being operable from a clamped condition wherein the steering column support bracket is clamped between the adjustment bracket and the bolt engaging portions of the clamping mechanism operating handle, to an undamped condition wherein the steering column support bracket is moveable relative to the adjustment bracket and the bolt engaging portions of the clamping mechanism operating handle. It will be appreciated that with such an arrangement the bolts need not cross over or under the steering column but can be located on a substantially on-centre line passing at right angles through the axis of the steering column. In a preferred embodiment, the respective flanks of the steering column support bracket extend outside the flanks of the reach adjustment bracket means. The innermost flanks can be spaced from the steering column outer tube so that a head of each bolt can lie between the inner side of the respective innermost flank and the outer side of the steering column outer tube. The slots in the flanks of the reach adjustment bracket means can be provided with a keyhole portion through which the head of a respective bolt can pass so as to be located on the inner side of the flank. Each bolt can be given both a left-hand and a right-hand thread. The threads can be multi-start threads. The reach adjustment bracket can be joined to the steering column outer tube by welding and the reach adjustment bracket means can be pressed, cast or extruded. For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: - Figure 1 iε a schematic view showing an adjustable vehicle steering column including a clamping mechanism, Figure 2 is a diagrammatic sectional view of the adjustable vehicle steering column clamping mechanism of Figure 1, and Figures 3, 4, 5, 6 and 7 are respective views of various possible forms that a reach adjustment bracket means of the clamping mechanism can take. Figure 1 shows an adjustable vehicle steering column 1 secured by brackets 2 and 3 and connected to a steering column rack 4. A steering wheel 5 is illustrated and the double arrow A illustrates the direction of possible vertical or rake adjustment of the steering wheel 5 and the double arrow B illustrates the direction of axial or reach adjustment thereof. A steering column clamping mechanism 6 includes an operating clamp handle 7 with the mechanism acting on the support bracket 3, which is also provided for rake adjustment, and a reach adjustment bracket means 8. The steering column support bracket 3 has two flanks 3A extending either side of a steering column outer tube 9, each flank 3A incorporating a slot 3B to permit rake adjustment of the steering column 1. The reach adjustment bracket means 8 can take various forms but in each case it is provided with two flanks 8A which extend on respective sides of the steering column outer tube 9 and lie adjacent the respective flanks 3B of the support bracket 3. In the embodiment illustrated, it is intended that the flanks 8A of the bracket means 8 lie inside the flanks 3B of the support bracket 3 and are spaced a sufficient distance from the outer surface of the steering column outer tube 9 to accommodate headε 10A of reεpective clamping bolts 10. Each flank 8A of the reach adjustment bracket meanε 8 is provided with a slot 8B extending parallel to the axis 9A of the steering column outer tube 1 and, in the form illustrated, these slots 8B are aligned with each other and with the axis 9A of the steering column outer tube 9. However, it is to be understood that the line of the slots 8B could be somewhat above or below the axis 9A. The εlotε 8B in the flankε 8A are each provided with a keyhole 8C to permit admission of the respective heads 10A of the two locking bolts 10, as illustrated in Figures 2 and 3. Once the heads 10A of the bolts 10 have been inserted, the keyholes 8C can be plugged by plugs such as the one in illustrated at 11 to prevent subsequent disengagement of the bolts 10. As intimated, the locking bolts 10 form part of the clamping mechanism and can be provided with squared rubbing surfaces as illustrated at 10B in Figure 3, these rubbing surfaces running along the edges of the slot 8B. These rubbing surfaces could be circular instead of square. Each bolt 10 is provided with a left-hand and a right-hand thread and the threads can be multi-start threads. Mounted on the threads are parts of the clamping mechanism operating handle 7 which extend to embrace the flanks 3A and 8A on both sides of the outer tube 9. It will be noted that the partε 7A of the operating handle 7 are mounted in threaded relationship on the locking bolts 10, each part 7A embracing an inner cone 12 associated with a clamping nut threaded on the bolt 10. Rotation of the operating handle 7 rotates the clamping nuts on the bolts 10 in opposite senses on the threads so that the parts 7A are drawn towards one another to cause the clamping nuts to clamp the two bracket 3 and 8 together to inhibit steering column adjustment. In the opposite direction of rotation, of the operating handle 7, the parts 7A are urged in the opposite sense to unclamp the two brackets to permit adjustment. Upon assembly of the clamping mechanism, the various components are mounted in a matched sense to obtain equal clamping effort on both sides of the steering column. Various embodiments of reach adjustment bracket means (8) are illustrated. In Figures 2 and 3, the reach adjustment bracket means 8 is in fact in two separate parts and can be formed by pressing, with the parts constituting the flanks 8A being spaced from the outer tube 9 and forming the bases of U-shaped parts, edges of which being welded at 13 for example to the outer tube 9. Figure 4 shows the reach adjustment bracket means 8 in the form of a saddle bracket straddling the outer tube 9 and again the bracket 8 can be pressed and then welded to the tube 9. Figure 5 is similar to Figure 4 but shows that the two flanks 8A can be joined at their lower edges by a lower plate 8D extending below the outer tube 9. In this case, the outer tube can be a drawn tube and again the reach adjustment bracket is welded to it. Figure 6 illustrates an embodiment similar to Figure 4 except that the unit can be cast or extruded. Figure 7 illustrates an embodiment similar to the Figure 3 embodiment except that keyhole slots are not provided but instead the slots 8B in the flanks 8A are open to the respective ends of the flanks 8A that are remote from the steering wheel end 14 of the steering column. This version can be applied to any of the embodiments discussed above to give an easier assembly capability.

Claims: CLAIMS ; 1. An adjustable vehicle steering column clamping mechanism (6) including a steering column support bracket (3) with two opposed slots (3B) therein and an adjustment bracket (8) arranged to be joined to the steering column outer tube, the adjustment bracket (8) having two slots (8B) positioned adjacent radially opposed portions of the steering column tube; there being a clamping mechanism operating handle (7) having two bolt engaging portions, and bolts (10) and associated clamping members on the bolts rotatable by said operating handle portions; characterised in that one bolt (10) slidably engages one adjustment bracket slot (8B) , extending through one steering column support bracket slot (3B) and threadedly engaging one clamping mechanism operating handle bolt engaging portion, and the other bolt (10) slidably engages the other adjustment bracket slot (8B) , extending through the other steering column support bracket slot (3B) and threadedly engaging the other clamping mechanism operating handle bolt engaging portion; the clamping mechanism operating handle (7) being operable from a clamped condition wherein the steering column support bracket (3) is clamped between the adjustment bracket (8) and the bolt engaging portions of the clamping mechanism operating handle (7) , to an unelamped condition wherein the steering column support bracket (3) is moveable relative to the adjustment bracket (8) and the bolt engaging portions of the clamping mechanism operating handle (7) . 2. An adjustable steering column clamping mechanism according to claim 1, wherein the steering column support bracket (3) has two flanks (3A) extending on either side of the steering column tube (9) , one slot (3B) being positioned in each flank (3A) . 3. An adjustable steering column clamping mechanism according to claim 1 or 2, wherein the adjustment bracket (8) has two flanks (8A) extending on either side of the steering column tube (9) , one slot (8B) being positioned in each flank (8A) . 4. An adjustable steering column clamping mechanism according to claim 3, wherein the adjustment bracket flanks (8A) are spaced from the steering column tube (9) and a head of each bolt (10) is between an inner side of a said adjustment bracket flank (8A) and the steering column tube (9). 5. A clamping mechanism according to claim 2, 3 or 4, in which the respective flanks (3A) of the steering column support bracket (3) extend outside the flanks (8A) of the reach adjustment bracket (8) . 6. A clamping mechanism according to claim 3 or 4, with or without claim 5, wherein each adjustment bracket slot (8B) opens to an end of its flank (8A) . 7. A clamping mechanism according to claim 3 or 4, with or without claim 5, wherein the slots (8B) in the flanks of the reach adjustment bracket (8) are provided with a keyhole portion (8C) through which the head of a respective bolt (10) can pasβ so as to be located on the inner side of the flank. 8. A clamping mechanism according to any one of the preceding claims, wherein one bolt (10) is given a left-hand thread and the other bolt (10) is given a right-hand thread. 9. A clamping mechanism according to claim 8, wherein the threads are multi-start threads. 10. A clamping mechanism according to any one of the preceding claims, wherein the reach adjustment bracket (8) is in two parts, each part being joined to the steering column outer tube (9) . 11. A clεunping mechanism according to any one of the preceding claims, wherein the reach adjustment bracket (8) is joined to the steering column outer tube by welding. 12. A clamping mechanism according to any one of the preceding claims, wherein the reach adjustment bracket (8) is formed by pressing, casting or extrusion. 13. An adjustable vehicle steering column incorporating a clamping mechanism according to any one of the preceding claims. 14. A vehicle steering column according to claim 13, wherein the bolts (10) of the clamping mechanism are located on a substantially on-centre line passing at right angles through the axis of the steering column (1) on either side thereof, respectively.

Inventors: BARTON LAURENCE GEORGE, HANCOCK MICHAEL THOMAS, BARTON, LAURENCE, GEORGE, HANCOCK, MICHAEL, THOMAS
Applicants: NASTECH EUROP LTD, NASTECH EUROPE LIMITED
Application year: 1996
Main classification: B62D1
IPC codes: B62D1