GB2142082A

GB2142082A - Ball and socket joints

Info

Publication number: GB2142082A
Application number: GB08316928A
Authority: GB
Inventors: Peter Grinnell
Original assignee: GKN Forgings Ltd
Current assignee: GKN Forgings Ltd
Priority date: 1983-06-22
Filing date: 1983-06-22
Publication date: 1985-01-09
Also published as: GB2142082B; GB8316928D0

Abstract

A ball and socket joint is provided with a protective cover 26 and retaining clip 32 therefor wherein one end 24 of the cover has a groove 28 to receive the clip and such grooved end of the cover is fitted within a co-operating groove 22 on the socket body. The clip 32 comprises slightly less than two convolutions of spring Wire and sealingly clamps the cover to the socket body by exerting an axial compressive force on the side walls of the cover groove 28. <IMAGE>

Description

SPECIFICATION Ball and socket joint This invention relates to a ball and socket joint of the type wherein a ball end of one member is tiltable and/or rotatable within a socket end of another member, the joint being protected against ingress of dirt and water by a flexible protective cover extending between the two members. For example such a joint is used in the steering and suspension gear of motor vehicles.

Motor vehicle ball and socket joints of the above type are well known in the art and attention has already been directed to the problem of sealing the flexible protective cover to the relatively movable members of the joint. For example GB 1 065 229 and GB 1487759 both teach the concept of applying a circular spring clip to a groove in the protective cover at the socket end of the cover whereby a radially inwardly directed force is applied by the clip to clamp the cover to the exterior of the socket body.

In both of these constructions the spring clip, in its relaxed state, is of a substantially smaller diameter than the socket housing and it can be difficult and damaging to the protective cover to expand the clip over the socket body into the position where it will snap into the groove on the cover.

It is an object of the present invention to provide a ball and socket joint having a protective cover and retaining clip therefor wherein the clip offers an improved fitting thereof onto the protective cover and socket body.

In accordance with the invention there is provided a ball and socket joint of the type having a protective cover extending between a member carrying the ball of the joint and a socket body, the cover having an annular circumferential groove on its exterior surface at that end thereof which fits over the socket body and the socket body having an annular circumferential groove for receiving said grooved end of the cover; a retaining clip being provided within the cover groove to retain said grooved end thereof within the socket body groove, said clip having at least one and one half helical convolutions with no part of one convolution in contact with another convolution when in its relaxed state and being axially compressed when located in the cover groove whereby the exert an axial force on each side wall of the cover groove to press each such side wall into sealing contact with the respective adjacent side wall of the socket body groove.

The retaining clip conveniently has a length of slightly less than two convolutions and is formed of a spring wire of rectangular cross sectional form whereby each convolution has a width greater than its height. Preferablythesaid rectangular crosssectional wire has rounded corners thereto.

Other features of the invention will become apparent from the following description given herein solely by way of example with reference to the accompanying drawings wherein: Figure 1 is a side elevation, half in cross-section of a ball and socket joint according to the invention with a protective cover and retaining clip therefor assembled over the joint, and; Figure 2 is an isometric view of the retaining clip in its relaxed state.

The construction of the ball and socket joint shown in Figure 1 is conventional with the exception of the means by which the protective cover is sealingly secured to the socket body.

Thus the operative parts of the joint comprise a pin 10 having a ball end 12 mounted for tilting or universal rotation within a plastics bearing 14 itself retained within a socket body 16. The joint is assembled by first of all fitting the ball end 12 into the plastics bearing 14 and then inserting the ball and bearing into the socket body 16 form the top thereof. A cover plate 18 is then secured in position over the bearing by turning the edges 20 of the upper part of the socket body 16 radially inwardly over the cover plate 18 whereby the plate exerts a predetermined compression on the bearing 14.

The lower end of the socket body 16 is provided with an exterior circumferential groove 22 for receiving an end 24 of a protective cover 26 which is conveniently formed of a flexible rubber or other elastomeric material. That end 24 of the cover 26 which fits within the socket body groove 22 is itself provided with an exterior circumferential groove 28 whilst the other end of the cover is stiffened by the inclusion of a bonded metal washer 30 to maintain such end in sealing and wiping contact with the pin 10.

The grooved end 24 of the cover 26 is retained in the socket body groove 22 by means of a retaining clip 32 of the type shown Figure 2 of the drawings.

This clip 32 is formed of spring wire of rectangular cross sectional form with rounded corners and, in its relaxed state as shown in Figure 2, has a length of slightly less than two convolutions with no part of any one convolution being in contact with another convolution. The internal diameter of the clip in its relaxed state is substantially equal to, or only very slightly less than, the diameter at the base of the groove 28 in the cover 26. To assemble the cover and clip onto the joint, the cover 26 is first of all passed overthe pin 10 so that the grooved end 24 of the cover fits within the groove 22 on the socket body and the clip 32 is then passed over the pin and the cover to fit into the cover groove 28. The clip 32 is axially compressed to fit into the cover groove 28 and, when fitted, will exert an axially outwardly directed compressive force on each side wall of the cover groove 28 to press such side wall into sealing contact with the respective adjacent side wall of the socket by body groove 22. In view of the fact that only very little radial expansion of the clip 32 is necessary to fit it over the cover and into the cover groove 28 it follows that the possibility of damage to the cover is minimised. When so assembled little or no radially inwardly directed force is applied from the clip 32 to the cover 26, the clamping action of the clip being effected virtually solely in an axial direction upon the side walls of the cover groove as aforesaid.

Claims

1. A ball and socket joint of the type having a protective cover extending between a memory carrying the ball of the joint and a socket body, the cover having an annular circumferential groove its exterior surface at that end thereof which fits over the socket body and the socket body having an annular circumferential groove for receiving said grooved end ofthe cover; a retaining clip being provided within the cover groove to retain said grooved end thereof within the socket body groove, said clip having at least one and one half helical convolutions with no part of one convolution in contact with another convolution when in its relaxed state and being axially compressed when located in the cover groove whereby to exert an axially force on each side wall of the cover groove to press each such side wall into sealing contact with the respective adjacent side wall of the socket body groove.

2. A ball and socket joint as claimed in Claim 1 wherein the retaining clip has a length of slightly less than two convolutions.

3. A ball and socket joint as claimed in either one of Claims 1 or 2 wherein the retaining clip is formed of a spring wire rectangular cross sectional form whereby each convolution of the clip has a width greater than its height.

4. A ball and socket joint having a protective cover and retaining clip constructed and arranged substantially as hereinbefore described with reference to the accompanying drawings.