GB2245663A

GB2245663A - Pivot mechanism incorporating means to take up wear between two parts thereof

Info

Publication number: GB2245663A
Application number: GB9107762A
Authority: GB
Inventors: Gerald Anthony Speich
Original assignee: Torrington Co Ltd; Torrington Co
Current assignee: Torrington Co Ltd; Timken US LLC
Priority date: 1990-05-08
Filing date: 1991-04-12
Publication date: 1992-01-08
Anticipated expiration: 2011-04-12
Also published as: GB9010303D0; GB9107762D0; GB2245663B

Abstract

A self adjusting pivot mechanism for a car steering column arranged to take up wear and backlash, includes a housing bracket (9) for receiving a steering column (10), the housing having opposed symmetrical tapered pinions (9A) received in corresponding female tapered portions (11A) of housing support brackets (11). The male and female tapered portions are resiliently urged towards one another by means of sprag washers (12) secured on extremities of the tapered portions (11A), which washers draw the parts (9A and 11A) towards one another. Meanwhile, relative rotational movement between the portions (9A and 11A) is accommodated. <IMAGE>

Description

1 PIVOT MECHANISM INCORPORATING MEANS TO TAKE UP WEAR BETWEEN TWO PARTS

THEREOF This invention relates to a pivot mechanism incorporating means to take up wear between two parts thereof.

The invention has particular relevance to car steering columns where historically there has been a problem of how to allow systems such as car steering columns to pivot, giving positional adjustment, without introducing noticeable backlash or free play into that system, whether that be wear or tolerance induced. Figure 1 schematically illustrates a car steering column arrangement with a steering wheel 1, with steering wheel movement being illustrated bv the arrows A. Reference numeral 2 illustrates a pivot which is free of looseness.

Common svstems in use todav tend to accept looseness and ignore the results, which leads to a poor user response, or alternatively a multitude of plastics and rubber parts are introduced to movement. These can prone to mishandling.

absorb clearances and danTD out be difficult to assemble and are As a result of the former, Figure 2 illustrates a housing 3 or the like, with a bolt 4 or the like intended to secure a mounting bracket 5. such a construction leads to an inherent clearance illustrated by way of example at 6.

Figure 3 illustrates the latter tendency to introduce a multitude of plastics and rubber parts and here it will be seen that the mounting bracket 5 is secured between the housing 3 and bolt 4 with the addition of a plastics washer 6 on one side of it and an 0-ring 7 and a "top hat" washer 8 on the other side of it.

is According to the present invention, there is provided a pivot mechanism incorporating means to take up wear between two parts of the mechanism which move relativelv to one another, said means including a male tapered part nesting in a corresponding female part, one of the two parts being resiliently loaded towards the other.

For a better understanding of the invention and to show how the same mav be carried into effect, reference will now be made, by way of example, to Figure 4 of the accompanying drawing, which illustrates diagrammatically a pivot mechanism according to the present invention.

Referring to Figure 4 of the drawing, a substantially cylindrical housing 9 surrounds and locates a shaft 10 such as a steering column shaft or a bearing or the like for such a shaft.

The housing 9 forms part of a pivot mechanism incorporating means to take up wear between two parts of the mechanism which move relatively to one another and, in the example illustrated, this means is duplicated.

The housing 9 is provided with two symmetrically-opposed, frustoconical male parts in the form of tapered pinions 9A which are located in corresponding female tapered parts 11A of respective housing support brackets 11.

0 3 The external tapered surfaces of the pinions 9A and the internal tapered surfaces 11A of the housing support brackets 11 are arranged to be mutually non-locking and they function by providing relatively rotatable surfaces which, by urging the tapers together, have no radial or axial free play.

The tapered parts are urged together by providing two sprag washers 12, respectively, which are designed to act as springs. Each sprag washer 12 is a simple press fit over the parallel pinion length of its respective pinion 9.A adjacent its outer end, where it protrudes through the aperture provided by the female part. Each washer is pressed on to its pinion with a preset load. Thus, the male and female parts are resiliently drawn towards one another by the washers 12 and the spring action of the washers 12 takes up any wear at the tapered surfaces so that the clearance is eliminated by the spring action, whilst allowing relative rotation.

It will be appreciated that the present pivot mechanism is easy to assemble, since the housing support bracket is simply located on their pinions and then the washers 12 are located with a preset load. only a small number of components are required and the result achieves good wear tolerance and no noticeable looseness or free play.

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Claims

CLAIMS:

1. A pivot mechanism incorporating means to take up wear between two parts of the mechanism which move relatively to one another, said means including a male tapered part nesting in a corresponding female part, one of the two parts being resiliently loaded towards the other.

A pivot mechanism according to claim 1, in which one of said parts is a housing to support a shaft or a shaft support bearing.

3. A mechanism according to claim 2, wherein said shaft or shaft support bearing forms steering column.

part of a car

4. A mechanism according to claim 1, 2 or 3, wherein said male tapered part comprises a tapered pinion.

5. A mechanism according to claims 2 and 4, wherein said tapered pinion forms part of said housing.

6. A mechanism said female part housing.

according to claim 4 or 5, wherein is part of a support bracket for said

7. A mechanism according to any one of the preceding claims, wherein one of said two parts is resiliently loaded towards the other by means of a sprag spring washer which is secured to the other of the two parts and is so located as to draw the two parts towards one another.

1

8. A mechanism according to claims 6 and 7, wherein said tapered pinion passes through an aperture provided by the female part of said housing support bracket and said washer is secured to a part of said pinion which lies on the side of said aperture remote from the main body of said housing, thereby acting to draw the housing and housing support bracket towards one another.

9. A mechanism according to any one of the preceding claims, wherein said means includes two of said male tapered parts nesting in corresponding female parts, the respective pairs of male and female parts being symmetrically opposed to one another.

10. A car steering column incorporating a pivot mechanism according to any one of the preceding claims.

11. A pivot mechanism, substantially as hereinbefore described with reference to Figure 4 of the accompanying drawing.

-)o -M Published 1991 at The Patent Office. Concept House. Cardiff Road. Newport. Gwent NP9 1RH. Further copies may be obtained from Sales Branch. Unit 6. Nine Mile Point, Cwmfelinfach, Cross Keys. Newport. NP1 7HZ. Printed by Multiplex techniques lid, St Mary Cray. Kent.