GB2300393A - Cycle wheel alignment clamp - Google Patents

Abstract

A shaft 8 provides a mounting for two jaws 12, 13, and two spacers 7 located between said jaws. All of these parts can move along shaft 8. Releasable fastening means 9, 11 operate to move the jaws towards each other, and hold them in the resulting position. In use, the jaws are positioned outside the cycle chain stays 2, the spacing elements are inserted between the chain stays and the wheel rim 6, centring the wheel, and the fastening means are tightened to hold the clamp and wheel in position. The fastening means may be a wing nut, or a pivoting cam arrangement. There may be a separate spacing element 4 for insertion between tyre 5 and cross member 3, or bottom bracket 1, to maintain rearward pressure on the wheel during fitting. One jaw may be fixed, and the other moveable. Rollers may be provided at each end of the shaft, to assist the movement of the clamp along the chain stays.

Description

CYCLE WHEEL ALIGNMENT CLAMP This invention relates to a cycle wheel alignment clamp.

Certain cycle wheels, including rear bicycle wheels, have to be centrally aligned when being fitted.

This is often because the axle of the wheel is prevented from travelling as far as possible into the two mounting slots, by virtue of the chain which can limit movement into the slots, or because of the mounting of gear apparatus in one of the slots.

Alignment of cycle wheels by hand is not very accurate and the wheel tends to move out of position anyway when the wheel nuts are tightened.

A cycle wheel needs to be aligned centrally with the wheel rim midway between the first and second chain stays which extend from the bottom bracket rearwards to the mounting points for the axle of the wheel.

According to the present invention, there is provided a cycle wheel alignment clamp which comprises: a shaft; first and second jaws extending laterally from the shaft, with provision for relative movement, along the axis of the shaft, between the first and second jaws; first and second spacing elements mounted on the shaft for free movement along the axis of the shaft, with the first and second spacing elements being mounted inboard of the first and second jaws, respectively; and releasable fastening means capable of causing the relative movement towards each other of the jaws and of holding the jaws in the resulting position; the arrangement being such that, in use, a first chain stay is located between the first jaw and the first spacing element, a second chain stay is located between the second jaw and the second spacing element, and the rim of the cycle wheel is located between the first and second spacing elements, and such that tightening of the fastening means causes the jaws to be moved towards each other with consequent central aligning of the wheel rim between the first and second chain stays.

In use of the alignment clamp, the clamp is passed between the spokes of the wheel and aligned appropriately with regard to the first and second chain stays and with the wheel rim and the clamp is then moved as far as possible in that direction away from the axle of the wheel and towards the cross member between the chain stays and/or the bottom bracket of the cycle frame.In view of the fact that the chain stays converge in the direction towards the bottom bracket, and/or in view of the possibility of the first and second spacing elements being wedge-shaped, movement of the alignment clamp towards the bottom bracket results in the spacing elements, being acted upon by the chain stays, centralising the wheel rim, with the fastening means then serving, through the action of the first and second jaws on the outer faces of the first and second chain stays, to move the jaws towards each other and to secure them in relation to the first and second chain stays.

In one embodiment of the present invention both the first and second jaws are movable along the shaft, and each of the jaws can have its own fastening means.

In an alternative embodiment one of the first and second jaws can be permanently fixed with regard to the shaft, with only the other of the jaws being movable with respect to the length of the shaft either towards or away from the first-mentioned jaw, with the fastening means then acting on only the other jaw.

To assist in movement of the jaws of the alignment clamp relative to the first and second chain stays in a direction towards the bottom bracket, the jaws may be provided with rollers which rotate in contact with the chain stays whilst still permitting a clamping action by the jaws on the respective chain stays.

in view of the fact that the first and second chain stays generally converge in a direction towards the bottom bracket, and that the sides of the wheel rim generally converge with the chain stays in the same direction, the first and second spacing elements could have parallel sides in planes parallel to the plane of the wheel, but it is preferable for the first and second spacing elements to have a wedged region.

With regard to the shaft, this could be circular over much of its length provided that the first and second jaws and first and second spacing elements can be held conveniently in appropriate working relationship relative to the first and second chain stays and wheel rim. With that consideration in mind, it is probably more convenient for the shaft to be non-circular in cross-section over the majority of its length. A square or elliptical shaft would permit the jaws and spacing elements to be mounted on the shaft without being able to rotate with respect to the shaft.

To avoid damaging any components of the bicycle the faces of the first and second jaws which are to abut the first and second chain stays could be formed of a rubber or plastics matcrial, and the working faces of the first and second spacing elements could similarly be formed.

With regards to the fastening means, this could take the form of a wing nut acting on an externally threaded end portion of the shaft and acting directly on the jaws or through the action of a force-transmitting sleeve.

Alternatively, some convenient pivoting cam arrangement could be employed which might be more rapid to operate.

During actuation of the alignment clamp there is a tendency, by virtue of the converging nature of the first and second chain stays, and possibly because the clamp is pushed forward manually anyway, for the alignment clamp to move towards the bottom bracket, possibly taking the wheel rim in that direction. This needs to be countered, because the axle of the wheel needs to be moved away from the bottom bracket in order to tension the chain appropriately. With that in mind, there can additionally be provided, as a separate component, a spacing element, for instance in the form of a wedge,which can be forced between the tyre of the wheel (in a region between the chain stays) and the bottom bracket or any cross member between the first and second chain stays, thereby tending to force the axle of the wheel away from the bottom bracket.Once this separate spacing element has been applied in this manner, the alignment clamp of the present invention can then be applied in the manner described above.

The third spacing element, that between the tyre and the cross member (or bottom bracket), need not be wedge-shaped but a wedge would probably be the most convenient shape. It could be of a sprung design, such that it would be compressed on being pushed between the tyre and the cross member (or bottom bracket). Its rear and front surfaces could be shaped so as to accommodate, respectively, the curvature of the tyre and any feature projecting from the cross member, such as a mudguard attachment feature. It could be made of metal, rubber, plastics or wood. It could be coated with a material such as plastics or rubber so as not to damage the bicycle frame. This third spacing element is not essential for use of the clamp as rearward pressure could be applied to the wheel manually, but it would be more convenient to have it.

To prevent rotation of the first and second spacing elements and the moving jaw about the shaft any shaft of noncircular section could be employed. passing through correspondingly shaped bores in the first and second spacing elements and the mounting for the moving jaw.

The part of the shaft bearing the first and second spacing elements could be circular in section with the first and second spacing elements also being circular (disc-shaped) and able to rotate about the axis of the shaft. Such circular spacing elements could be parallel-sided but it might be more convenient if they had a wedge-shaped region.

In order to accommodate variation, as between different bicycles, in the distance between the wheel rim and the chain stays it might be convenient for the first and second spacing elements to be of variable width. They might, for instance, be of a sprung design such that they would be compressed on being inserted between the wheel rim and the chain stays.

Although it would be preferable for the first and second spacing elements to be wedged between the chain stays and the wheel rim, because of the rigidity of the latter, the clamp could also be used with the first and second spacing elements wedged between the chain stays and the tyre.

If the jaws were ifl the form of rollers this would help tc align the clamp at right ang!es to the iongitud.nai S of the bicycle and thus assist in achieving equal insertion of the first and second spacing elements between the chain stays and the wheel rim. which is necessary for central alignment of the wheel. It might also heip to achieve equa' insertion of the first and second spacing elements if they andfor the chain stays bore visible markings.

The alignment clamp might also be useful for wheel truing. If the wheel were rotated between the first and second spacing elements (not fully inserted into the gaps between the chain stays and the wheel rim) any buckiing of the wheel rim would be evident from variations in the distance between the wheel rim and either spacing element. and the appropriate wheel spokes could then be loosened or tightened to true the wheel.

The clamp could be used with the shaft either below or above the chain stays and the jaws pointing, respectively, upwards or downwards.

For a better understanding of the present invention and to illustrate how the same may be carried into effect reference will now be made, by way of example, to the accompanying drawings: Figure 1 is a horizontal section of one embodiment of the present invention (view from above or below); Figure IA is a vertical section through the shaft and one spacing element of the arrangement shown in Figure 1; Figure 2 is a view from the side of the embodiment illustrated in figure 1; and Figure 3 is a vertical section of the embodiment illustrated in figures 1 and 2 (view from the rear).

Figure I shows the bottom bracket. no. 1, from which two chain stays. nos. 2, extend rearwards. No. 3 is the cross member between the cha n stays which is usually present. No.

4 is the third spacing element inserted between the cross member and a tyre, no. 5. If there is no cross member a larger spacing element can be inserted between the bottom bracket and the tyre. The rear side of the spacing element is shown curved to accommodate the curvature of the tyre. The wheel rim. no. 6, is shown held in a central position between the chains stays by the first and second spacing elements.

nos. 7. The first and second spacing elements are shown mounted on a square shaft. no. 8, along which they are free to slide by virtue of square apertures through them which match the square section of the shaft and through which the shaft passes (see Figure 1A on same sheet). The moving and fixed jaws of the clamp, nos. 12 and 13 respectively. are shown clamped against the outsides of the chain stays, held in position by pressure from the wing nut, no. 9, transmitted to the moving jaw by the sleeve, no. Ii. The moving jaw is shown mounted on a block which is free to slide along the shaft in the same way as described above for the spacing elements. The jaws are shown to be circular in section.In this embodiment the jaws are rollers, their outer surfaces being free to rotate about their own vertical axes and thus to roll along the outside surfaces of the chain stays. The wing nut is shown screwed inwards along the threaded end portion, no. 10.

of the shaft, exerting pressure on the moving jaw towards the fixed jaw, via the sleeve.

Figure 2 shows the bottom bracket, no. 1, from which a chain stay, no. 2, extends rearwards. No. 3 is the cross member between the chain stays which is usually present. No.

4 is the third spacing element, inserted between the cross member and a tyre, no. 5. If there is no cross member a larger spacing element can be inserted between the bottom bracket and the tyre. One of the first and second spacing elements, no 7 is shown inserted between the chain stay and the wheel rim. no. 6 The moving jaw, no. 12. mounted on a sliding block. is shown clamped onto the outside of the chain stay and held in position by pressure from the wing nut. no.

9. (transmitted via the sleeve which is not visible). The clamp is shown in position between adjacent wheel spokes. nos 14.

Figure 3 shows the fixed jaw, no. 13, clamped against the outside of one of the chain stays. no. 2. One of the first and second spacing elements, nos. 7 is wedged between that chain stay and the wheel rim, no. 6. and the other spacing element is wedged between the other chain stay and the wheel rim. The moving jaw, no. 12, mounted on a sliding block, is clamped against the outside of the second-mentioned chain stay, held in position by pressure transmitted via the sleeve.

no. II from the wing nut. no. 9. The two jaws and the first and second spacing elements are shown mounted on a square shaft, no. 8, and the wing nut is shown screwed inwards along the threaded end portion. no. 10. of the shaft.

Claims (11)

1 A cycle wheel alignment clamp comprising a shaft; first and second jaws extending laterally from the shaft, with provision for relative movement, along the axis of the shaft, between the first and second jaws; first and second spacing elements mounted on the shaft for free movement along the axis of the shaft, with the first and second spacing elements being mounted inboard of the first and second jaws, respectively; and releaseable fastening means capable of causing the relative movement towards each other of the jaws and of holding the jaws in the resulting position; the arrangement being such that, in use, a first chain stay is located between the first jaw and the first spacing element, a second chain stay is located between the second jaw and the second spacing element. and the rim of the cycle wheel is located between the first and second spacing elements, and such that tightening of the fastening means causes the jaws to be moved towards each other with consequent central aligning of the wheel rim between the first and second chain stays.

2 A cycle wheel alignment clamp as claimed in Claim 1 wherein both the first and second jaws are movable along the shaft and each has its own fastening means.

3 A cycle wheel alignment clamp as claimed in Claim 1 wherein one of the first and second jaws is permanently fixed with regard to the shaft and the other jaw is movable along the length of the shaft towards and away from the fixed one, the fastening means acting only on the movable jaw.

4 A cycle wheel alignment clamp as claimed in any preceding claim, wherein the jaws are provided with rollers which rotate in contact with the chain stays (to assist the movement of the jaws along the chain stays of the cycle), whilst still permitting r clamping action by the jaws on the respective chain stays.

5 A cycle wheel alignment clamp as claimed in any preceding claim, wherein the first and second spacing elements each hrve a wedge-shaped region.

6 A cycle wheel alignment clamp as claimed in any preceding claim, wherein at least the portion of the shaft along which the spacing elements and the movable jaw or jaws are free to slide is non-circular in cross-section so that the spacing elements and the movable jaw or jaws cannot rotate about the shaft.

7 A cycle wheel alignment clamp as claimed in any preceding claim, wherein the working faces of the jaws and the spacing elements are formed of material which would not damage parts of the cycle with which they come into contact, the material preferably beingirubber or plastics material.

O A cycle wheel alignment clamp as claimed in any preceding claim, wherein the fastening means is a wing nut acting on an externally threaded end portion of the shaft and acting either directly or via a force-transmitting sleeve on the jaws, or the single movable jaw.

9 A cycle wheel alignment clamp as claimed in any one of Claims 1-7, wherein the fastening means is a pivoting cam arrangement.

10 A cycle wheel alignment clamp as claimed in any preceding claim, which is provided with a third, separate, spacing element to be inserted between (a) the tyre and (b) the bottom bracket or any cross-member between the chain stays, to maintain rearward pressure on the wheel during fitting.

11. A cycle wheel alignment clamp substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.