Clamping mechanism for fixing a steering column housing

Abstract: Clamping mechanism for a steering column housing adjustable perpendicularly to the longitudinal direction of the steering column, said mechanism comprising a clamping bolt and a lever with which the bolt can be tensioned and the column housing fixed, and a spring-loaded element between housing and bolt, the lever (10) and the bolt (4) being coupled by pins (18) whose centre lines cross that of the bolt (4) when it is in released condition, said pins being provided between a cup (16) fixed to the bolt and the lever, the pins being longer than the distance, measured in longitudinal direction, between cup and lever in released condition of the bolt and a certain degree of tilting of the pins on their supporting points being possible.

Description: The invention relates to a clamping mechanism for fixing a steering column housing of a motor vehicle, which is adjustable in a direction which is perpendicular to the longitudinal direction of the steering column said mechanism comprising a clamping bolt which is provided in the steering column housing, as well as a lever with which the bolt can be tensioned axially and the column housing fixed, and at least one spring-loaded element provided between housing and bolt whereby, when the lever moves in the direction of the clamping position the spring-loaded element is released, before the lever reaches the clamping position. Such a clamping mechanism is known from the German patent specification DE-C 902 586. With this known clamping mechanism the steering column housing is slid on the clamping bolt and the lever is journalled loose on the clamping bolt. On the clamping bolt a nut is provided which is locked against rotation relative to the bolt and is provided with a cam which can co-operate with a notch in the lever. Friction plates are provided on the clamping bolt on both sides of the steering column housing. As long as the cam of the nut is located in the notch of the lever the spring-loaded element is released, the friction plates are unloaded and the clamping connection is removed, so that the steering column housing is displaceable. When as a result of pivoting of the lever the cam is lifted from the notch, whereby the spring is tensioned and the friction plates are loaded, the steering column housing is clamped. The disadvantage of the known clamping mechanism is that when the steering column housing is fixed there is no feel of the degree of clamping which is reached. It is desirable that there is a certain palpable "turning point" in the movement of the lever, i.e. that there is a point whereby the lever, when being moved toward its clamping position, is just a little more difficult to move than shortly therebehind. If such a point is not reached, it must be an indication that play, occurring as a result of wear, must be eliminated. The aim of the invention is to offer a solution for this problem and is characterized in that the lever and the bolt are coupled by one or more pins whose centre lines cross the centre line of the bolt when it is in released condition, said pins being provided between a cup fixed to the bolt and the lever; each pin having a length which is greater than the distance between cup and lever in released condition of the bolt and tilting of the pins about their supporting points is possible such that when the lever moves toward the clamping position the pins pass a position in which the centre line of at least one of the pins is parallel with the centre line of the bolt. The advantage of the clamping mechanism according to the invention is that the clamping action is independent of wear of the thread of the clamping bolt, that the spring-loaded element provides compensation of the unavoidable fitting tolerances and furthermore, that it is possible to give the clamping bolt a certain pre-tension. A suitable embodiment of the invention is characterized in that there are two pins (18). The invention will be further explained in the following description with reference to the drawing. The drawing illustrates in: Fig. 1 a diagrammatic representation of a suitable embodiment of the invention, in section according to the line I - I in fig. 2; Fig. 2 a side view of the embodiment according to fig. 1. In fig. 1 reference number 1 indicates a steering column housing which is provided under the dashboard panel 2 of the motor car. The steering column 3 is diagrammatically indicated. Said steering column is, with the housing 1, vertically adjustable. In the steering house a clamping bolt 4 is provided, which is provided with a threaded end 8 on which a locking nut is screwed. A Belleville washer 7 is placed between the locking nut 9 and a tubular part of the dashboard panel 2. At the other end of the bolt 4 a catch washer 16 is fixed to the bolt. A lever 10 is provided freely rotatable about the bolt 4, whilst between the lever and the tubular part of the dashboard panel 2 there is located an axial needle bearing 17. Between the washer 16 and the lever 10 a pair of pins are provided, in such a manner that they extend substantially parallel to the axis of the bolt 4. Provided in the washer 16 and the lever 10 are fitting holes, journalling the pins. Said pins are somewhat longer than the distance, measured in the direction of the axis of the bolt 4, between the journalling locations of the pins in washer 16 and lever 10. This means that when the pins 18, by rotation of the lever 10, are tilted into a position exactly parallel to the axis of the bolt, a tensile force against the action of the spring 7 is exerted in the bolt 4. This force is then the clamping force for fixing the steering column. The pins 18 are furthermore provided in such a manner that they still allow a small further movement (at an angle of about 10°) of the lever 10 before it strikes the stop 15. It is true that becauce of this further tilting of the pins 18 the clamping force slightly decreases but this has appeared not to be disadvantageous. The case is that when the lever 10 is moved a slightly greater force has to be overcome shortly before reaching the stop, and this can be felt. Moreover when this feeling does not occur it is a sign that the nut 9 needs to be readjusted. No. 30 illustrates another cam for the stop in the other direction.

Claims: Clamping mechanism for fixing a steering column housing (1) of a motor vehicle, which is adjustable in a direction which is perpendicular to the longitudinal direction of the steering column (3), said mechanism comprising a damping bolt (4) which is provided in the steerig column housing (1) as well as a lever (10) with which the bolt (4) can be tensioned axially and the column housing (1) fixed, and at least one spring-located element (7) provided between housing (1 ) and bolt (4) whereby, when the lever (10) moves in the direction of the clamping position the spring-loaded element (7) is released before the lever (10) reaches the clamping position, characterized in that the lever (10) and the bolt (4) are coupled by one or more pins (18) whose centre lines cross the centre line of the bolt (4) when it is in released condition, said pins (18) being provided between a cup (16) fixed to the bolt (4) and the lever (10), each pin (18) having a length which is greater than the distance between cup (16) and lever (10) in released condition of the bolt (4) and tilting of the pins (18) on their supporting points is possible such that when the lever (10) moves toward the clamping position the pins (18) pass a position in which the centre line of at least one of the pins (18) is parallel with the centre line of the bolt (4). Clamping mechanism according to claim 1, characterized in that there are two pins (18).

Inventors: KESTER WILHELMUS LEONARDUS MAR, KESTER, WILHELMUS LEONARDUS MARIA
Applicants: VOLVO CAR BV, VOLVO CAR B.V.
Application year: 1987
Main classification: B62D1
IPC codes: B62D1, F16B2