ALEXANDER IAN CHRISTOPHER ANDREW (GB)
ALEXANDER PATRICK JAMES (GB)
ALEXANDER IAN CHRISTOPHER ANDR (GB)
WO2004014717A1 | 2004-02-19 |
DE10032105A1 | 2002-01-17 | |||
DE19738770A1 | 1999-03-11 | |||
FR2912109A1 | 2008-08-08 | |||
US6089675A | 2000-07-18 | |||
GB2401590A | 2004-11-17 |
CLAIMS
1. A front wheel assembly for a folding bicycle, comprising a front wheel with hub, and a wheel carrier carrying the wheel between two carrier arms thereof and pivotably connectible with the bicycle to be movable between a use position with the wheel releasably fastened to front forks of the bicycle and a folded position with the wheel removed from the forks, the hub having projections engaged in recesses in the arms thereby to mount the wheel in the wheel carrier and the arms being resiliently splayable to disengage the projections from the recesses and thereby permit removal of the wheel from the carrier.
2. An assembly as claimed in claim 1 , wherein the arms are resiliently bendable along the length thereof to permit deflection away from the projections.
3. An assembly as claimed in claim 1 or claim 2, wherein the arms are connected together by connecting means in the region of the circumference of the wheel, the connecting means being resiliently bendable to permit deflection of the arms away from the projections.
4. An assembly as claimed in claim 3, wherein the connecting means are provided by a mudguard.
5. An assembly as claimed in claim 4, wherein the carrier comprises two further arms disposed on either side of the wheel and extending between the first two arms at an angle thereto and the mudguard, the two further arms being resiliently splayable in company with the first two arms.
6. An assembly as claimed in any one of the preceding claims, wherein each of the arms with the recesses has a guide channel communicating with the recess of that arm for guidance of the associated projection into and out of the recess.
7. An assembly as claimed in claim 6, wherein each channel runs into the associated recess at a side thereof so that the recess is of correspondingly reduced depth at that side.
8. An assembly as claimed in claim 6 or claim 7, wherein the channel is oriented to extend forwardly from the recess into the use position of the carrier.
9. An assembly as claimed in any one of the preceding claims, wherein the arms with the recesses have respective cam surfaces simultaneously co-operable with the projections of the hub to cause resilient deflection of the arms so as to allow re- engagement of the projections in the recesses and thereby remounting of the wheel in the carrier.
10. An assembly as claimed in claim 9, wherein the cam surfaces diverge from one another in a direction away from the recesses.
11. An assembly as claimed in claim 9 or claim 10, wherein the cam surfaces are provided on protrusions usable as handles to assist manual splaying of the arms.
12. An assembly as claimed in any one of claims 9 to 11 when appended to any one of claims 6 to 8, wherein each cam surface is formed by the base of a prolongation of the associated channel.
13. An assembly as claimed in any one of the preceding claims, wherein the projections are stub axles.
14. An assembly as claimed in claim 13, wherein the stub axles are formed by end portions of an axle extending through a body of the hub.
15. An assembly as claimed in any one of the preceding claims, comprising quick- release fastening means for releasably fastening the wheel carrier together with the wheel to the forks.
16. A folding bicycle comprising a front wheel assembly as claimed in any one of the preceding claims. |
FRONT WHEEL ASSEMBLY FOR A FOLDING BICYCLE
The present invention relates to a front wheel assembly for a folding bicycle and to a folding bicycle equipped with such an assembly.
Folding bicycles normally include, as an aspect of reduction to a more compact form, a folding front wheel which can be pivoted to, for example, overlie the bicycle frame. One such arrangement is described in the specification of United Kingdom Patent No. 2 401 590. This provides a wheel carrier pivotably connected to front wheel forks of the bicycle and carrying the wheel in the manner of a subframe. The wheel carrier with wheel is preferably secured to the forks by a quick-release clamp. In order to be able to repair a punctured tyre or replace a tyre or tube it is necessary to remove the wheel itself from the wheel carrier. This normally requires separation of the quick-release clamp from the rest of the assembly, but this does not automatically free the wheel, which may be positively located in the carrier so that loads are transmitted directly from the wheel to the carrier and not through the intermediary of the clamp. Provision can be made for dismantling the carrier or removal of retaining elements keeping the wheel in place, but either solution involves a measure of inconvenience and may add cost and weight to the assembly as well as increase the number of parts.
It is therefore the principal object of the invention to provide a front wheel assembly for a folding bicycle in which wheel removal from a wheel carrier can be carried out more simply and without penalties with respect to cost, weight and number of parts.
Other objects and advantages of the invention will be apparent from the following description.
According to the present invention there is provided a front wheel assembly for a folding bicycle, comprising a front wheel with hub, and a wheel carrier carrying the wheel between two carrier arms thereof and pivotably connectible with the bicycle to be movable between a use position with the wheel releasably fastened to front forks of the bicycle and a folded position with the wheel removed from the forks, the hub having projections engaged in recesses in the arms thereby to mount the wheel in the wheel carrier and the arms being resiliently splayable to disengage the projections from the recesses and thereby permit removal of the wheel from the carrier.
Removal of the wheel from the wheel carrier, if or when this is required, can thus be accomplished in simple manner merely by flexing the arms, for which purpose the arms are given sufficient resilience in the carrier construction. The wheel in the use position of the carrier is nevertheless firmly located in the carrier by engagement of the hub projections in the recesses in the arms, so that loads transmitted by road shock and other load sources are passed on directly to the wheel carrier. Disassembly of the carrier to disengage the projections from the recesses in order to extract the wheel from the carrier is thus not necessary and the carrier does not have to be constructed with removable or releasable parts specifically for that purpose.
In one embodiment the arms are resiliently bendable along the length thereof to permit deflection away from the projections. Alternatively or additionally, the arms can be connected together by connecting means in the region of the circumference of the wheel, the connecting means being resiliently bendable to permit deflection of the arms away from the projections and having the form of, for example, a mudguard. The amount of deflection required to splay the arms sufficiently to release the projects may be comparatively small, for example in the order of a few millimetres, so that the level of resilience required is low and need not compromise the basic rigidity of the carrier.
In a developed construction, the carrier preferably comprises two further arms disposed on either side of the wheel and extending between the first two arms at an angle thereto and the mudguard, the two further arms being resiliently splayable in company with the first two arms. This represents a triangulated construction imparting substantial strength to the carrier.
For preference, each of the arms with the recesses has a guide channel communicating with the recess of that arm for guidance of the associated projection into and out of the recess. Mechanically positive guidance of the projections in this manner eases the task of wheel removal and refitting and ensures that, for refitting, the projections are directed into the recesses without requiring particular attention to centre the projections relative to the recesses. In a preferred construction each channel runs into the associated recess at a side thereof so that the recess is of correspondingly reduced depth at that side. The reduced depth has the consequence that the projections can disengage from the recesses at one side, i.e. the side at which the channel communicates, before splaying of the arms
to the full extent of the maximum depths of the two recesses. The channel itself is for preference oriented to extend forwardly from the recess in the use position of the carrier, which results in a convenient direction of extraction of the wheel from the carrier after the assembly has been detached from the bicycle forks, but with the assembly still pivotably coupled to the bicycle.
The process of refitting the wheel to the carrier can be further assisted if the arms with the recesses have respective cam surfaces simultaneously co-operable with the projections of the hub to cause resilient deflection of the arms thereby to allow re-engagement of the projections in the recesses. This arrangement provides, in effect, automatic splaying of the arms as the wheel is pushed into position in the carrier. The cam surfaces are preferably arranged to diverge from one another in a direction away from the carrier, the extent of divergence being, for preference, substantially the same as or only slightly more than the required amount of splaying of the arms. Advantageously, the cam surfaces are provided on protrusions usable as handles to assist manual splaying of the arms. If the cam surfaces are present in conjunction with the guide channels, each cam surface can then be conveniently formed by the base of a prolongation of the associated channel.
For preference, the assembly comprises quick-release fastening means for releasably fastening the wheel carrier together with the wheel to the forks. Any desired form of quick- release fastening means can be used, but it remains entirely possible to use a conventional connector, such as a threaded spindle with nuts, functioning as a clamp.
An embodiment of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which:
Fig. 1 is a schematic side view of a front wheel assembly embodying the invention, the assembly being shown fitted to the front forks of a folding bicycle and in a use position;
Fig. 2 is a detail perspective view, to an enlarged scale, of a front part of an arm of a wheel carrier of the assembly of Fig. 1 ;
Fig. 3 is a schematic cross-section, to an enlarged scale and along the line A-A of
Fig. 1 , of a centre part of the assembly of Fig. 1 ; and
Fig. 4 is a view similar to Fig. 3, but with the assembly removed from the forks and a wheel in the process of being removed from the carrier.
Referring now to the drawings there is shown a front wheel assembly 10 for a folding bicycle, which is illustrated only in fragmentary form in Fig. 1 and which includes, apart from elements which are not illustrated, a frame down tube 11 carrying a pair of front wheel forks 12 movable in usual manner by handlebars (not shown). The folding bicycle can be transformed from an extended use state to a folded state for carriage or storage. For this purpose the front wheel assembly 10, when incorporated in such a bicycle, is pivotably attached to a bracket 13 at the forks 12 to be pivotable between a use position in which the assembly is fitted to the forks, as shown in Fig. 1 , and a folded position (not shown) in which the assembly is removed from the forks. The folded position is reached by pivoting the assembly forwardly about a pivot axis at the bracket 13 and then turning the forks through approximately 180° to bring the assembly into overlapping relationship with the down tube 11.
The principal elements of the front wheel assembly 10 are a front wheel 14, which includes a hub 15, a front wheel carrier 16 carrying the wheel 14 and a quick-release clamp 17 for fastening the wheel carrier 16 together with the wheel 14 to the forks 12. The wheel carrier 16 is a rigid structure composed - in this embodiment - of two pairs 18 and 19 of arms, the arms of each pair 18 or 19 being disposed on either side of the wheel 14 and each meeting an arm of the respective other pair 19 or 18 at the wheel hub 15, and a mudguard 20 uniting the arms in the region of the wheel circumference. The quick-release clamp 17, which is indicated merely schematically in Fig. 1 , fastens the wheel carrier 16 to the forks 12 by way of mutually aligned open-ended slots 21 formed in the forks 12 to extend in the fore-and-aft direction of the bicycle with the slot open ends facing forwardly with respect to the direction of travel of the bicycle.
The front wheel assembly 10 described thus far is generally known and similar to that described in the specification of United Kingdom Patent No. 2 401 590.
Part of the quick-release clamp 17 is shown in the schematic cross-section of Fig. 3, in particular in the state in which the wheel carrier 16, together with the wheel as represented by the hub 15 in the figure, is fastened by either one or both of the pairs of wheel carrier
arms to the forks 12. The pair 19 of arms which are generally horizontal is shown in Fig. 3 by way of arbitrary choice; the point of fastening to the forks can equally well be disposed in the other pair 18 of arms or at a junction common to both pairs. The hub 15 includes a central tubular through axle 22, which extends beyond mutually opposite ends of a body of the hub to form projections in the shape of protruding coaxial stub axles 22a. The body of the hub conventionally incorporates ball or other bearings (not shown) by which the wheel is rotatable about the axis of the stub axles.
Each of the wheel carrier arms of the pair 19 has a spigot 23 coaxial with the stub axles and projecting away from the hub 15. Each spigot is slidably engageable in the slot 21 of the associated fork 12 so as to couple the front wheel assembly 10 to the forks 12.
The wheel carrier arms of the pair 19 additionally have, at mutually facing sides, recesses 24 in which the stub axles 22a are seated to provide firm location of the hub 15 in the arms. This location is enhanced by provision in each of those arms of a further, larger diameter recess 25 adjoining the recess 24 and seating a respective cylindrical end portion 15a of the body of the hub 15.
The quick-release clamp 17 comprises a spindle 26 which extends through the tubular axle 22 and through coaxial bores in the spigots 23 to protrude, by mutually opposite end portions, outwardly of the spigots. A respective locating member 27 for locating the wheel carrier and wheel in the forks 12 is placed on each of the spindle end portions. The locating members 27 are movable relative to one another longitudinally of the spindle 26 for fitting the assembly to and release of the assembly from the forks 12 and are tightenable relative to one another, such as by an over-centre pivot lever acting on one of the locating members via a cam, to fix the spigots 23 in the slots 21. Various quick- release clamp constructions and principles of operation suitable for this purpose are known from the state of the art. When tightening of the locating members 27 is relaxed, the members can be relatively displaced longitudinally of the spindle to move clear of recesses associated with the slots 21 and thus allow the spigots to slide out of the slots for removal of the wheel carrier 16 and wheel 14 from the forks.
If, following removal of the wheel carrier 16 and wheel 14 from the forks 12, it is desired to separate the wheel from the carrier, for example for tyre puncture repair or tyre replacement, this can be carried out after detaching the quick-release clamp 17 from the
wheel carrier and wheel. Detaching takes place by, for example, removing one of the locating members 27 and withdrawing the spindle 26 from the axle 22. The wheel 14 remains attached to the wheel carrier 16 due to continued engagement of the stub axles 22a in the recesses 24 in the arms of the pair 19 and also engagement of the hub body end portions 15a in the recesses 25.
To enable disengagement of the stub axles 22a and the hub body end portions 15a from their respective recesses 24 and 25 the wheel carrier 16 is constructed so that the arms of the pair 19, and with them the arms of the other pair 18, can be resiliently flexed, in particular splayed apart, by an amount sufficient to permit the stub axles and hub body end portions to move clear of the recesses. The resilience permitting such splaying can be achieved by a resiliently bendable construction of the arms themselves or - preferably - by a resiliently bendable construction of the mudguard 20 functioning as connecting means connecting the arms of each pair. It is, of course, possible for both the mudguard and the arms to have a resilient construction. In either case, the amount of displacement required to splay the arms sufficiently is relatively small, for example about 4 millimetres in a practical example. As a consequence, the level of resilience incorporated in the arms and/or mudguard has a negligible influence on the overall structural stability of these components. In the fitted position of the assembly 10, any scope for resilient movement is precluded by the clamping action of the clamp 17.
To assist movement of the stub axles 22a into and out of the recesses 24 in the arms of the pair 19 each of these arms is provided with a guide channel 28 communicating with the associated recess 24 and having a width the same as the recess diameter, as shown more clearly in the enlarged perspective view of Fig. 2. The channel 28 runs into the recess 24 at the front thereof, i.e. the side facing forwardly in the use position of the wheel assembly, so that the depth of the recess is correspondingly reduced at that side. The depth of each recess 25 is similarly reduced at the same side and in such a manner that the associated cylindrical end portion 15a of the hub body is able to slide into and out of the recess 25 conjunctively with the stub axle movement into and out of the recess 24.
Remounting of the front wheel 14 in the wheel carrier 16 is assisted by the provision of cam surfaces 29 which diverge from one another in a direction away from the recesses 24 and 25 and which, when the wheel is pushed between the arms from the front, simultaneously co-operate with the distal ends of the stub axles 22a to progressively urge
the arms apart. Each cam surface 29 is formed by the base of a prolongation of the associated channel 28, so that the stub axles 22a can move continuously, with positive guidance, into the recesses 24. The bias generated by the resilient deflection of the arms thereupon causes them to snap back into the unsplayed state and thus seat the stub axles 22a in the recesses 24 and the hub body end portions in the recesses 25.
Demounting of the front wheel 14 on the other hand is carried out by manually splaying the arms of the pairs 18 and 19, for which purpose the cam surfaces 29 can be provided on protrusions or prolongations of the arms, the protrusions being usable as handles by the person removing the wheel.
A front wheel assembly embodying the invention thus combines secure location of the wheel in the wheel carrier with ease of removal and refitting, no tools being required except to such extent as may be necessary for extraction of the quick-release fastening system.