GB1576283A

GB1576283A - Ball bearing connection

Info

Publication number: GB1576283A
Application number: GB28120/77A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1976-07-05
Filing date: 1977-07-05
Publication date: 1980-10-08
Also published as: BE856359A; FR2357774A1; FR2357774B3; ES229719Y; ES229719U

Description

PATENT SPECIFICATION

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(22) Filed 5 July 1977

(21) Application No. 28120/77 (31) Convention Application No.

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(44) Complete Specification published 8 Oct. 1980

(51) INT. CL.3 F16C 19/18

(52) Indexv at acceptance

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(32) Filed 5 July 1976 in

(54) A BALL BEARING CONNECTION

(71) I, Tullio Campagnolo, an Italian citizen, of Corzo Padova, 168 — 36100 Vicenza, Italy, do hereby declare the invention, for which I pray that a patent 5 may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: —

This invention relates to ball bearing con-10 nections, particularly, but not exclusively, for the steering units of bicycles.

The ball bearing connection between the front fork of a bicycle and the front end tube of the bicycle frame is normally ob-15 tained by means of a ring of balls interposed between facing race tracks formed on a flange, which is solid with the fork, and on a cap on a bushing, the lower end of which is solid with the front end tube, 20 the arrangement being such that the balls roll on the said race tracks, keeping in contact therewith at diametrically opposite points thereof.

Given the heavy load which is usually 25 applied to this ball bearing connection during use of the bicycle and which, on particular occasions, can assume exceptional values (it will be enough to consider an additional load on the handlebars, which 30 is very likely to happen), such a ball bearing connection has always constituted a weak point in relation to bicycle structures and has always demanded special attention and care, even in the choice of the material 35 used, with evident consequences on the costs.

The present invention has for its object to provide any improved ball bearing connection by means of which the above-40 mentioned disadvantages of the known ball bearing connections are obviated.

With this object in view there is provided according to the invention a ball bearing connection comprising a shaft, a tubular 45 member surrounding the shaft and sup ported thereon by a thrust bearinjtp$r0ft&ipg£ viding for relative rotation between the shaft and the tubular member, wherein the bearing comprises radially inner and outer concentrically arranged rings of 50 bearing balls, a first *ball race in the form of an annular ridge of wedge-shaped cross-section provided on an annular flange rigid with the shaft, the annular ridge projecting axially from the flange between the 55 inner and outer rings of bearing balls so that the flank surfaces of said ridge form race tracks for said inner and outer rings of bearing balls respectively, and a second ball race formed by the interior surfaces 60 of an annular recess in an annular part rigid with one end of the tubular member,

said interior surfaces consisting of a radially disposed base surface and inner and outer side wall surfaces coaxial with the 65 shaft and extending from the base surface towards the flange on opposite sides respectively of the ridge.

With this arrangement, each of the balls of each of the two rings of balls is sup- 70 ported at three points, namely on one side against an inclined flank surface of the annular ridge and on the other side against a lateral wall surface and against the upper wall surface of the annular recess in the 75 cap. The load is thus distributed in a far more uniform and rational way than in the past and, however heavy the condition of use, the steering ball bearing connection will no longer represent a weak and problem- 80 atic point thereof.

The invention is now described in further detail, by way of example, with reference to the accompanying drawings, in which: —

Figure 1 is a partly sectioned elevational 85 view of a conventional bicycle steering connection: —

Figure 2 is a view similar to that of Figure 1 of a bicycle steering connection embodying the present invention; and 90

1576283

15

Figure 3 is a detail in section and on an enlarged scale, of the bicycle steering connection of Figure 2.

The conventional bicycle steering con-5 nection shown in Figure 1 comprises a flange 1 solid with the fork F of a bicycle, a cap 2 provided on the lower end of a bushing 3 solid with the front end tube C of the bicycle frame- and a ring of balls 10 4 interposed between ball races provided respectively on the flange 1 and on the cap 2. As can be seen, the balls 4 rotate in contact with these ball races at diametrically opposite points a' and a".

The bicycle connection embodying the present invention, shown in Figures 2 and 3, likewise comprises a flange 11 which is solid with the shaft of the fork F and a cap 13 provided on the lower end of a 20 bushing 14 which is solid with the front tube C of the bicycle frame. Two concentric rings of balls, namely a radially inner ring of balls 15 and a radially outer ring of balls 16, are however provided be-25 tween the flange 11 and the cap 13. The flange 11 is formed integrally with an annular ridge 12 of wedge-shaped cross-section which projects upwardly into an annular recess formed in the under part of the 30 cap 13. Each of the balls of the inner ring of balls 15 is in contact at b with a race track on the radially inner frusto-conical flank surface 12' of the annular ridge 12 and at c and d with a race track on the inner 35 lateral cylindrical wall surface 13' and a first race track *©n the upper end surface 13" respectively of the annular recess in the cap 13, while each of the balls of the outer ring of balls 16 is in contact at e with a race track on the outer frusto-conical flank surface 12" of the annular ridge 12 and at / and g with a race track on the outer lateral cylindrical wall surface 13"' and a second race track on the upper end 45 surface 13" respectively of the annular recess in the cap 13.

The load is accordingly transmitted through two rings of balls, instead of only one, and the balls in their turn each trans-50 mit the load at three points instead of two. The distribution of the load is thus more widely spread and is moreover spread in a

40

more rational way than in the conventional bicycle steering connection shown in Figure 1.

It will readily be appreciated that the ball bearing arrangement employed in the bicycle steering connection described above with reference to Figures 2 and 3 has a considerably greater load-carrying capacity and also a much longer working life than that employed in the conventional bicycle steering connection shown in Figure 1. The choice of materials is also less critical with the arrangement shown in Figures 2 and 3 than with the conventional arrangement shown in Figure 1, with the result that tha former is cheaper to manufacture than the latter.

WHAT I CLAIM IS:—

l; A ball bearing connection comprising a shaft, a tubufar member surrounding the shaft and supported thereon by a thrust bearing providing for relative rotation between the shaft and the tubular member, wherein the bearing comprises radially inner and outer concentrically arranged rings of bearing balls, a first ball race in the form of an annular ridge of wedge-shaped cross-section provided on an annular flange rigid with the shaft, the annular ridge projecting axially from the flange between the inner and outer rings of bearing balls so that the flank surfaces of said ridge form race tracks for said inner and outer rings of bearing balls respectively, and a second ball race formed by the interior surfaces of an annular recess in an annular part rigid with one end of the tubular member, said interior surfaces consisting of a radially disposed base surface and inner and outer side wall surfaces coaxial with the shaft and extending from the base surface towards the flange on opposite sides respectively of the ridge.

2. A bicycle steering connection substantially as described with reference to and as shown in Figures 2 and 3 of the accompanying drawings. ;i

REDDIE & GROSE Agents for the Applicant 16 Theobalds Road London WC1X 8PL -

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Printed for Her Majesty's Stationery Office by The Tweeddale Press Ltd., Berwick-upon-Tweed, 1980. Published at the Patent Office, 25 Southampton Buildings, London, WC2A .1 AY. from which copies may be obtained. . ..