Rocker arm mechanism for clamping an adjustable steering column

Abstract

The invention relates to a rocker arm mechanism on a clamping device in an adjustable motor vehicle steering column for the detachable fixing of a housing for the steering column to a mounting on the chassis. The housing and mounting may be connected by means of at least one pair of co-operating friction surfaces which may be clamped together by means of the rocker arm mechanism. The rocker arm mechanism thus comprises a centrally arranged stud (3), which is displaceable in the direction of the mid-longitudinal axis (13) thereof and at least one rocker arm (6) arranged with the longitudinal axis (14) thereof roughly parallel to the stud mid-longitudinal axis (13). Said rocker arm (6) is supported either directly or indirectly on a stud head (4) and the other end thereof is located in a recess (10) on the front face of an operating collar (5). Said rocker arm (6) may be tipped by turning the operating collar (5), out into a locking closed position over the axial extent, parallel to the stud mid-longitudinal axis (13) and in the opposite direction into an open position. According to the invention, the operating collar (5) comprises at least one recess (11) for a further rocker arm (6) on the second front face facing away from the first rocker arm. The other end of said rocker arm (6) is supported on a pressure disc (7) which may be axially displaced in the direction of the mid-axis of the operating collar (5).

Description

[0001] The present invention pertains to a tilting pin mechanism for the clamping device of a motor vehicle steering column, whose position can be adjusted, with the features described in the preamble of patent claim 1.

[0002] Such a tilting pin mechanism is present, e.g., to build up the clamping forces in a clamping device corresponding to DE 44 00 306 A1. This specification discloses a clamping device, by which a housing accommodating the steering column is in contact with a bracket that is a rigid part of the body in the clamped state with corresponding friction surfaces. The clamping forces are built up by means of a plurality of tilting pins, which are supported with one end in an abutment at the housing and with their other end in an abutment at a bolt collar. The rotation of the bolt in one direction causes that the tilting pins can be brought into a locking stop position beyond an axial extended position in parallel to the axis of the bolt, in which stop position the necessary pressing forces are applied for the friction surfaces arranged between the bracket, which is a rigid part of the body, and the housing. During the rotation of the bolt in the opposite direction, the tilting pins come into a release position, in which the clamping connection is abolished and in which the tilting pins are sloped at a small angle in relation to the longitudinal axis of the bolt.

[0003] The clamping device described in the above-mentioned document, using a tilting pin mechanism, has proved, in principle, to be successful, but it has certain drawbacks, especially in regard to increased requirements on the clamping action. These are especially that the clamping path, i.e., the travel performed by the tilting pins from their release position into the locking position, is relatively short. In addition, due to the fact that the position of the tilting pin passes over beyond the axial extended position into a locking position, some of the theoretically existing clamping path, which is short anyway, is lost due to the fact that the tilting pins are held in the stable locking position. The fact that an abutment, e.g., in the form of an axial needle bearing, which permits the rotary movement of the actuating element to tilt off the tilting pin under force, is necessary for the tilting pin mechanism in question in the existing state of the art, has turned out to be another drawback.

[0004] The object of the present invention is therefore to improve a tilting pin mechanism of this class, which was described in the introduction, such that longer clamping paths can be obtained. In addition, the mechanism according to the present invention shall have compact dimensions, it shall have a simple design and be inexpensive.

[0005] This object is accomplished according to the present invention by the technical teaching of claim 1 in conjunction with the class-forming features.

[0006] According to this technical teaching, the actuating ring, which brings about the tilting off of the tilting pins fitted in between the actuating ring and a bolt collar during rotation, has at least one recess for an additional tilting pin on the second front side facing away from the first-named tilting pins, wherein the other end of this additional tilting pin is supported in a thrust washer that is axially displaceable in the direction of the central axis of the actuating ring.

[0007] Due to this design according to the present invention, rotation of the actuating ring brings about a bilateral lifting movement of the tilting pins mounted in the front sides of the actuating ring. The travel can thus be doubled compared with the tilting pin mechanisms known from the state of the art. Since the recesses for the tilting pin or for the tilting pins arranged in both front sides are arranged offset in relation to one another, the mechanism according to the present invention has extremely compact dimensions despite the doubling of the travel.

[0008] Special embodiments of the subject of the present invention appear from the features of the subclaims in conjunction with the technical teaching of claim 1.

[0009] It proved to be particularly advantageous to arrange two mounts arranged offset by 180° in relation to one another for one tilting pin each at each of the two front sides of the actuating ring. The mounts at one front side are arranged offset by 90° in relation to those of the other front side. The bilaterally offset arrangement of the needle pairs stabilizes the middle actuating ring, as a result of which the number of tilting pins, which is usually three, can be reduced, which simplifies the manufacture and the assembly.

[0010] Moreover, provisions are made in another advantageous embodiment of the subject of the present invention that only two of the tilting pins present are in the “over-the-dead-center position,” i.e., beyond [“in der” at the end of line 18, p. 3 of German original should be deleted—Tr.Ed.] the axial extended position in parallel to the central longitudinal axis of the bolt, in the lockable stop position of the actuating ring, whereas the other two tilting pins are arranged exactly in the axial extended position. Due to the different arrangement of the tilting pins in the locking position, the clamping path can be additionally increased and the clamping action of the entire mechanism can thus be increased.

[0011] The rotation of the actuating ring can be brought about by coupling the said actuating ring with a hand lever.

[0012] An exemplary embodiment of the subject of the present invention will be explained in greater detail below on the basis of the drawings attached. In the drawings,

[0013] FIG. 1 shows a side view of the tilting pin mechanism according to the present invention,

[0014] FIG. 2 shows a sectional view through the mechanism according to the present invention corresponding to the section line A-A in FIG. 1,

[0015] FIG. 3 shows a sectional view through the tilting pin mechanism corresponding to section line B-B in FIG. 1, and

[0016] FIG. 4 shows a sectional view corresponding to section line C-C in FIG. 2.

[0017] Adjoining components of the steering column tilting pin mechanism are not shown in the view of the tilting pin mechanism in the individual drawings for the sake of clarity. FIG. 1 shows the tilting pin mechanism, designated by 1 in its entirety, together with a hand lever 2 coupled with the tilting pin mechanism 1. The hand lever 2 is used to actuate the tilting pin mechanism, whose detailed design is illustrated on the basis of FIGS. 2 through 4.

[0018] The entire mechanism comprises essentially a centrally arranged bolt 3 with an end-side bolt collar 4, an actuating ring 5, to which the hand lever 2 is fastened, a total of four tilting pins 6, as well as two thrust washers 7 and 8 arranged on the side of the actuating ring 5. With its outside facing away from the tilting pins, the thrust washer 8 is in contact with the bolt collar 4. Spherical recesses 9, whose contours are adapted to the end of the tilting pins 6, are present in the thrust washer 8. With their ends facing away from the thrust washer 8, the tilting pins 6 are arranged in corresponding recesses 10 of the actuating ring 5, which are designed as ball sockets. In the exemplary embodiment being shown, the thrust washer 8 acts as a contact surface for two tilting pins, wherein the tilting pins are arranged on a common radius offset by 180°.

[0019] The view in FIG. 3 shows that on the front side that faces away from the thrust washer 8, the actuating ring 5 likewise has, moreover, two recesses 11, in which tilting pins 6 are again accommodated. These tilting pins are supported, on the one hand, at the bottom of the recess 11, which are [sic—Tr.Ed.] designed as ball sockets analogously to the recesses 10. The other end of the tilting pins 6 is supported on the thrust washer 7, which likewise has recesses 12 of a hemispherical design corresponding to the end of the tilting pins 6, analogously to the thrust washer 8. The diameters of the recesses 10 and 11 are selected to be such that the tilting pins are arranged in the holes with a slight angular offset but essentially in parallel to the central longitudinal axis 13 of the bolt 3. Rotation of the actuating ring 13 by means of the hand lever 2 causes the slightly obliquely positioned bolt 3 to be brought first into a position in which its longitudinal axis 14 is directed in parallel to the central longitudinal axis 13 of the bolt 3. Further rotation of the actuating ring 5 then causes the tilting pins to be brought into a corresponding stable stop position beyond the above-mentioned parallel alignment.

[0020] Due to the fact that rotation of the actuating ring 5 brings about a change in position and, as a result of this, a lifting movement of the tilting pins 6 being moved by the actuating ring 5, the travel is doubled compared with prior-art tilting pin mechanisms and the possible clamping forces generated by the tilting pin mechanism for the detachable fastening of an adjustable steering column are substantially increased as a result.

[0021] The view in FIG. 4 shows clearly once again that two tilting pins projecting from a front side of the actuating ring are arranged offset by 180° on a common circumferential radius, and the tilting pins of the opposite front side are arranged offset by 90° in relation to the first ones. This arrangement leads to a self-stabilization of the tilting pin mechanism, so that the hitherto common design with three tilting pins on a common circumferential radius can be eliminated.

[0022] The lifting movement of the tilting pins 6 brings about an axial displacement of the thrust washers 7 and 8, as a result of which holding forces can be built up within the clamping mechanism for a motor vehicle longitudinal [typo in German original for the word meaning “steering”—Tr.Ed.] column within the friction pairs present there in a manner that is not shown here.

[0023] Provisions are made in a special embodiment of the subject of the present invention to use only two of the four existing tilting pins 6 for locking the tilting pins in the clamped position. This means that two tilting pins 6 are in the over-the-dead-center position in the locking position of the tilting pin mechanism, whereas the longitudinal axes 14 of the other two tilting pins are directed in parallel to the central longitudinal axis 13 of the bolt 3. The travel of these tilting pins 6 is therefore not reduced by the over-the-dead-center position as a consequence of the locking, so that the lifting is increased, albeit slightly, compared with the exemplary embodiment described first.

List of Reference Numbers:
1.  Tilting pin mechanism
2.  Hand lever
3.  Bolt
4.  Bolt collar
5.  Actuating ring
6.  Tilting pins
7.  Thrust washer
8.  Thrust washer
9.  Recess
10. Recess
11. Recess
12. Recess
13. Central longitudinal axis
14. Longitudinal axis

Claims

1. Tilting pin mechanism, preferably for the clamping device of a motor vehicle steering column, whose position is adjustable, for detachably fixing a housing accommodating the steering column at a bracket that is a rigid part of the body, wherein the housing and the bracket have at least one cooperating friction surface pair that can be pressed against each other by means of the tilting pin mechanism, with a said, centrally arranged bolt (3), which is displaceable in the direction of its said central longitudinal axis (13) and with at least one said tilting pin (6), whose said longitudinal axis (14) is arranged approximately in parallel to the said central longitudinal axis (13) of the said bolt, wherein the said tilting pin (6) is supported on one side directly or indirectly at a said bolt collar (4) and is accommodated at its other end in a said recess (10) on the front side of a said actuating ring (5), and wherein the said tilting pin (6) can be tilted into a lockable stop position and in the opposite direction into a release position by rotating the said actuating ring (5) beyond the axial extended position in parallel to the said central longitudinal axis (13) of the said bolt,

2. Tilting pin mechanism in accordance with claim 1,

3. Tilting pin mechanism in accordance with claim 2,

4. Tilting pin mechanism in accordance with one of the claims 1 through 3,

5. Tilting pin mechanism in accordance with one of the claims 2 through 4,

6. Tilting pin mechanism in accordance with one of the claims 2 through 4,

7. Tilting pin mechanism in accordance with one of the claims 1 through 6,