GB2135399A

GB2135399A - A pedal bearing for a bicycle

Info

Publication number: GB2135399A
Application number: GB08402245A
Authority: GB
Inventors: Alfred Thun
Original assignee: Alfred Thun GmbH and Co KG
Current assignee: Alfred Thun GmbH and Co KG
Priority date: 1983-02-23
Filing date: 1984-01-27
Publication date: 1984-08-30
Also published as: NL8400525A; GB2135399B; IT8419707A0; IT1173313B; FR2541222A1; GB8402245D0

Abstract

A pedal bearing for a bicycle comprises a housing for insertion into a sleeve (12) of a bicycle frame. The pedal shaft (5) has two shoulders (7) spaced apart and shaped as rolling-contact races which face opposite races (6) in the housing. Rolling-contact elements (8) are arranged between the races. The rolling-contact races (6) are axially adjustable and lockable to adjust and set the bearing play. The housing consists of two cup-shaped housing parts (1, 2) having their open ends facing and screwed together, the bases (3) of which are shaped to provide the internally coaxially arranged rolling-contact races (6). The housing parts may be of plastics materials, with the rolling contact races of steel (Fig. 2, not shown). A centering bushing (17) is forced against the interior of sleeve (12) by a nut (16). <IMAGE>

Description

SPECIFICATION A pedal bearing for a bicycle The invention relates to a pedal bearing for a bicycle, comprising a housing detachably insertable into the pedal bearing frame sleeve which houses a pedal shaft which has two shoulders which are spaced apart axially within the housing, which shoulders are shaped as rolling-contact races on the faces opposite to rolling-contact races in the housing, with revolving rolling-contact elements arranged between the races, the rolling-contact races of the housing being axially adjustable and lockable in order to adjust the bearing play.

A pedal bearing of this known kind is preassembled in fully functional form and subsequently inserted into the frame sleeve of the bicycle frame. Correct functioning can therefore be checked before fixing into the bicycle frame and any irregularities can be remedied. Usually the housing consists of a bushing having equal circular annular cross-sections along its total length with tapped bores arranged in both its ends into each of which a bearing plate shaped internally as a rolling-contact race is screwed.

One of these bearing plates is constructed for adjustment relative to the bushing in the direction of the longitudinal extension thereof and is secured by means of a locking nut, in order to permit the most favourable rolling-contact bearing play to be selected.

However, in order to ensure satisfactory running characteristics for the pedal shaft, this makes it necessary to have the two screw connections for attaching the bearing plates in absolutely precise mutual coaxial alignment.

A main aim of the invention is to provide an improved pedal bearing for a bicycle of this kind, which has whilst the advantage of simplicity of production and of assembly already achieved by the prior art, and is even simpler and cheaper to produce.

According to the invention there is provided a pedal bearing for a bicycle, comprising a housing detachably insertable into the pedal bearing frame sleeve which houses a pedal shaft which has two shoulders which are spaced apart axially within the housing, which shoulders are shaped as rolling-contact races on faces opposite to rolling contact races in the housing, with revolving rollingcontact elements arranged betweed the races, the rolling-contact races of the housing being axially adjustable ana lockable in order to adjust the bearing play, characterised in that the housing comprises two substantially cup-shaped housing parts which are aligned with their open ends facing and which are screwable together axially and have bases through which the pedal shaft passes, the internal surfaces of which bases are shaped as co-axial rolling-contact races.

By this means only one screw connection is necessary to complete the housing. This results in the desired simplification of production and assembly, with a 50% reduction in the number of possible sources of faults which can result in the housing parts being arranged in mutually incorrect positions, as compared to the prior art.

Preferably the two housing parts are of circular section and have different external diameters, a tapped bore is provided in the open end of the first housing part which is of larger diameter, whereas the second, smaller diameter housing part has in the region of its open end a male threaded region which screws into the tapped bore in coaxial alignment with the first housing part.

The first housing part may be approximately half as long as the second housing part.

This results in further simplification of production, saving of material, and a reduction of the deadweight of the overall pedal construction.

It is also possible for the first time to pass electric leads through the frame sleeve in the region of the second smaller diameter housing part, without the leads being damaged by the pedal bearing.

A locking nut may be screwed on the male threaded region of the second housing part, which nut abuts the end face of the first housing part, in order to fix the preselected bearing plan.

The invention further provides that the first housing part has an outwardly extending flange arranged around its base for application against the adjacent end face of the frame sleeve, and the second housing part has at its base end a male threaded region onto which is threaded a locking nut which abuts against the other end face of the frame sleeve.

These measures make it possible to assemble simply the completed pedal bearing in the frame sleeve of a bicycle with simple means, with the pedal bearing fitted both into internally smooth frame sleeves and into those having tapped bores.

It is therefore also possible for bicycle frames which have been constructed to receive pedal bearings of the prior art, to be fitted with a pedal bearing according to the invention.

In the preferred embodiment, in order to ensure installation of the preassembled pedal bearing into the frame sleeve free from radial play, the external diameter of the first housing part, along the major part of its longitudinal extension, is so much smaller than the internal diameter of the frame sleeve that the first housing part is arranged with coarse radial play in the frame sleeve in this region, and adjacent to the flange the first housing part has a relatively short region engageable into the frame sleeve with fine play.

In this case the clearance fit region could also be formed by a prefabricated distance ring plugged onto the first housing part.

Still further according to the invention a centering bushing, which is fitted onto the base end part of the second housing part has an envelope which is tapered inwardly of the bearing, which centering bushing is constructed for tensioning both against the interior of the adjacent frame sleeve and also against the second housing part, by means of the screw nut arranged on the second housing part.

To simplify and reduce the cost of production, both housing parts may be made of plastics material and are constructed for mutual selflocking screw engagement. By this means the housing parts can be produced from master patterns far more cheaply than when making them of steel.

Furthermore, the production and assembly of a locking nut screwed onto the male thread of one housing part and abutting onto the adjacent end face of the other housing part, in order to ensure the preselected rolling-contact bearing play, is superfluous.

Although plastics materials are particularly well suited for the production of self-locking screw connections, they do not have particularly good bearing properties, and to ensure high functional properties and a long useful life of the pedal bearing, the rolling-contact races may be formed by metal shells, for example hardened steel, which are fixed permanently to the housing parts; preferably incorporated during the moulding of the housing parts.

The shells are sunk in the housing parts and are arranged to terminate internally flush with the interior of the housing parts, in order to obtain an optimally compact pedal bearing and to improve the arrangement of the shell securely in position on the housing parts.

Stays on the shells may engage into the housing parts. The shells may be roughened externally; for example to have a milled or knurled surface.

Seaiing rings may be arranged in the bores of both housing parts and are engaged by the pedal shaft. Encircling grooves may be formed in the walls of the bores, into which grooves protruding sealing rings are fitted.

For this purpose annular lip seals cooperating with the pedal shaft may be shaped in the bores of the housing parts.

Some embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a pedal bearing for a bicycle in longitudinal section, and Figure 2 shows another embodiment, also in longitudinal section.

In both the embodiments, a housing consists of two substantially cup-shaped housing parts 1 and 2 screwed together coaxially with their open ends facing each other.

Concentrically arranged rolling-contact races 6 are arranged internally of housing bases 3, which have centrally arranged bores 4 for the passage of a pedal shaft 5. In the embodiment of Figure 1 , the races are shaped in the housing parts 1 and 2 which are made of steel. Opposite the rollingcontact races 6 there are shaped rolling-contact races 7 on the pedal bearing shaft 5, and rollingcontact elements 8 which are balls in this embodiment are arranged to revolve between the races 6 and 7. Needle bearings, for example, could be provided instead of ball bearings if appropriate.

There is a tapped bore 9 in the open end of the housing part 1, which is of larger external diameter than the housing part 2, for screwing the two housing parts 1 and 2 together, the housing part 2 having an external threaded zone 10 which engages with the tapped bore 9, when the zone 10 is screwed into the tapped bore 9.

The lengths of the threaded zones are such that the most favourable rolling-contact play can be provided by adjustment of the screwing of the zone 10 into the bore 9.

In order to ensure a preselected rolling-contact play, a locking nut 11 is screwed on to the male threaded region 10 and abuts frictionaliy against the end face of the housing part 1.

This preassembled pedal bearing is inserted removably into a bicycle frame sleeve 12. For this purpose there is a flange 1 3 on the end of the housing part 1 which abuts axially against the facing end face of the frame sleeve 12.

Adjacent the flange 13 and nearer to its open end, the housing part 1 has a relatively short region 14 which fits the internal diameter of the frame sleeve 12, and which is plugged into the frame sleeve 12 with a fine clearance fit. The external diameter of the rest of the housing part is slightly smaller so that it is housed with coarse play within the interior of the frame sleeve 12.

By contrast, the housing part 2 has on its terminal base part a further male threaded region 1 5 on which a nut 16 is screwed.

A centering bushing 1 7 which is conically tapered, externally is threaded over the end part of the housing part 2 and is applied frictionally against the housing part 2 and the interior of the frame sleeve 12 by means of the nut 1 6.

The centering bushing 1 7 has a shaped bracing flange 18 with at least one longitudinally oriented slit 1 9 in order to produce the above-described frictional application for a relatively small outlay of force even when there is a relatively large play.

In the embodiment of Figure 1, all the parts are of steel, and the rolling-contact races 6 and 7 have hardened surfaces.

In the pedal bearing shown in Figure 2, at least the housing parts 1 and 2 are made of plastics material, and the rolling-contact races are formed by relatively thin-walled prefabricated shells 6' of hardened steel.

The shells may have stays which engage into the housing parts. The shells may be roughened externally.

The shells 6' are inserted into the housing parts 1 and 2 during the moulding, casting, pressing, or injection-moulding of the latter, and are permanently connected to them. Rolling-contact races 7 shaped on the pedal shaft 5 are provided opposite each of the shells 6'.

Rolling-contact elements 8, shown as balls, are arranged to revolve between the rolling-contact races 6 and 7.

However, in the embodiment of Figure 2, the screwthreads are dimensioned so that the male threaded region 10 screws so tightly in the tapped bore 9 that spontaneous accidental detachment is excluded, and the locking nut 11 is not needed.

The axial lengths of the threaded regions are such that the most favourable rolling-contact bearing play can be adjusted in each case.

This preassembled pedal bearing is removably fitted into a bicycle frame sleeve 12 in the same way as shown in Figure 1.

In the bores 4 of both housing parts 1 and 2 of the pedal bearing shown in Figure 2, there are encircling grooves 20 into which sealing rings 21 cooperating with the pedal shaft 5 are inserted.

With the exception of the rolling-contact elements 8 of the pedal shaft 5 and of the sleeve 1 2 attached to the bicycle frame, all the other parts in Figure 2 are made of plastics material.

Claims

1. A pedal bearing for a bicycle, comprising a housing detachably insertable into the pedal bearing frame sleeve which houses a pedal shaft which has two shoulders which are spaced apart axially within the housing, which shoulders are shaped as rolling-contact races on faces opposite to rolling-contact races in the housing, with revolving rolling-contact elements arranged between the races, the rolling-contact races of the housing being axially adjustable and lockable in order to adjust the bearing play, characterised in that the housing comprises two substantially cupshaped housing parts which are aligned with their open ends facing and which are screwable together axially and have bases through which the pedal shaft passes, the internal surfaces of which bases are shaped as co-axial rolling-contact races.

2. A pedal bearing according to Claim 1, characterised in that the two housing parts are of circular section and have different external diameters, a tapped bore is provided in the open end of the first housing part which is of larger diameter, whereas the second, smaller diameter housing part has in the region of its open end a male threaded region which screws into the tapped bore in coaxial alignment with the first housing part.

3. A pedal bearing according to Claim 2, characterised in that the first housing part is approximately half as long as the second housing part.

4. A pedal bearing according to Claim 2 or Claim 3, characterised in that a locking nut arranged to abut the end face of the first housing part, is threaded on the male threaded region of the second housing part.

5. A pedal bearing according to any one of Claims 1 to 4, characterised in that the first housing part has an outwardly extending flange arranged around its base for application against the adjacent end face of the frame sleeve, and the second housing part has at its base end a male threaded region onto which is threaded a locking nut which abuts against the other end face of the frame sleeve.

6. A pedal bearing according to Claim 5, characterised in that the external diameter of the first housing part, along the major part of its longitudinal extension, is so much smaller than the internal diameter of the frame sleeve that the first housing part is arranged with coarse radial lay in the frame sleeve in this region, and adjacent to the flange the first housing part has a relatively short region engageable into the frame sleeve with fine play.

7. A pedal bearing according to any one of Claims 2 to 6, characterised in that a centering bushing, which is fitted on the base end part of the second housing part has an envelope which is tapered inwardly of the bearing, which centering bushing is constructed for tensioning both against the interior of the adjacent frame sleeve and also against the second housing part, by means of the screw nut arranged on the second housing part.

8. A pedal bearing according to any one of Claims 1 to 7, characterised in that both housing parts are made of plastics material and are constructed for mutual self-locking screw engagement.

9. A pedal bearing according to Claim 8, characterised in that the rolling-contact races are formed by metal shells, particularly of hardened steel, fixed permanently to the housing parts.

10. A pedal bearing according to Claim 9, characterised by shells which are incorporated in the housing parts during the moulding thereof.

11. A pedal bearing according to any one of Claims 8 to 10, characterised in that the shells are sunk in the housing parts and are arranged to terminate internally flush with the interior of the housing parts.

12. A pedal bearing according to any one of Claims 8 to 11, characterised in that stays engaging into the housing parts are arranged on the shells.

13. A pedal bearing according to Claim 12, characterised in that the shells are roughened externally.

14. A pedal bearing according to any one of Claims 1 to 13, characterised in that sealing rings are arranged in the bores of both housing parts and are engaged by the pedal shaft.

15. A pedal bearing according to Claim 14, characterised in that encircling grooves are formed in the walls of the bores, into which grooves protruding sealing rings are fitted.

1 6. A pedal bearing according to Claim 14, characterised in that annular lip seals cooperating with the pedal shaft are shaped in the bores of the housing parts.

1 7. A pedal bearing substantially as herein described with reference to Figure 1 or Figure 2.