GB2510857A

GB2510857A - Bicycle frame and forks

Info

Publication number: GB2510857A
Application number: GB201302660A
Authority: GB
Inventors: Mark Stebles
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-02-15
Filing date: 2013-02-15
Publication date: 2014-08-20
Anticipated expiration: 2033-02-15
Also published as: GB2510857B; GB201302660D0

Abstract

A frame and forks for a vehicle, especially suited to a bicycle are disclosed having a structure 7,13 which serve as a mudguard and performs the function of supporting dropouts (8, 15, figure 1A) thus obviating the chain stay, seat stay and/or fork blades employed for the purpose in a conventional bicycle frame. The vehicle may include suspension arrangements (figure 3A), and the mudguard structure(s) may further comprise carrier rack(s) 39, 40 and/or storage compartments (25, figure 2A)

Description

I

BICYCLE, FRAME AND FORKS

Technical field

[001] The present invention relates to the field of bicycle frames, especially, but not exclusively, push bicycle frames. The invention also relates to the provision of ancillary features such as mudguards and luggage racks. The invention may also apply to tricycles, quad cycles and cycles propelled or assisted by electric motors or internal combustion engines.

Prior Art

[002] The most common form of conventional bicycle frame is known as a diamond (or double triangle) frame consisting of a first triangle and second triangle. The first triangle consists of a top tube, down tube, head tube and seat tube. The seat tube is common to the second triangle formed additionally from seat stays and chain stays. The seat and chain stays extend rearwardly, respectively from near the opposite ends of the seat tube to a joint where the rear wheel axle is supported. Support for the rear wheel axle is usually in adjacent extending slots known as rear drop outs. The top tube and down tube extend forwardly, respectively from the top and bottom end of the seat tube to a junction where they support a head tube. The head tube provides a mounting for conventional forks which depend from the head tube to mount an axle which supports the front wheel. The conventional forks comprise an assembly of a steerer tube, a crown and one, more usually two blades, which descend from the crown to mount dropouts for engagement with a wheel axle. The dropout is a plate including a slot to receive the axle. The drop outs facilitate the removal and replacement of the wheel and are sometimes separable components to facilitate damage repair.

A few bicycle frames, usually specialised track bicycles may use horizontal slots to receive the rear wheel axle and some drop outs may not have slots disposed perfectly vertically, for the purposes of this application the term drop outs should be understood to mean all arrangements for securing the wheel axle unless otherwise stated.

[003] The bicycle frame must be sufficiently strong, stiff and resilient to support the weight of the rider and any other payload, avoid wasting energy in flexing yet flex sufficiently in appropriate directions to absorb shock and damp vibration.

Conversely the frame must be light to avoid wasting energy under acceleration and climbing. A few special custom built bicycles have high performance aerodynamic fairings which greatly reduce the coefficient of drag to improve aerodynamics and top speed, however, for a variety of reasons none of these bicycles are practical for normal use. The aerodynamics of the conventional bicycle are poor with a high coefficient of drag requiring extra work to propel.

[004] Mudguards are commonly attached to a bicycle frame to reduce or prevent water and mud (mud) from spraying off of either wheel onto the rider. A mudguard is usually a panel which is mounted to extend approximately normal of a radius of the wheel and between the wheel tyre and the rider so that the panel will deflect mud sprayed from the wheel away from the rider. However, conventional mudguards add to both the weight and aerodynamic drag of the bicycle. The fitting of mudguards is also something of an issue in that mud guards usually require mounting by means of machine screws received into screw holes formed in the frame or onto lugs welded or bonded to the frame. These mounting features add to the steps required to fabricate a frame and will either weaken the frame or add to its weight. Certain light weight mudguards may be attached to the frame by other means including compression screws, clamps, clips, cable ties or straps. However, such mudguards tend to be easily damaged are vulnerable to theft, and often rattle annoyingly. It is often impossible to fit full length mudguards particularly to suspension mountain bikes or racing road bicycles at all. However, a steady stream of mud sprayed into the face of the rider is not conducive to road safety and discourages the rider.

[005] The present invention seeks to alleviate at least one of the technical disadvantages discussed above.

Statement of invention

[006] According to a first aspect the present invention provides a vehicle frame and forks having each of front and rear wheel mounts, the front wheel mounts being supported by a front structure and the rear wheel mounts being supported by a rear structure, wherein at least one of said structures is shaped to serve as a mudguard.

[007] In a preferred embodiment of the invention the vehicle frame is a frame for a bicycle and has a rear structure which at least partially replaces each of the seat stays and chain stays In such a bicycle frame the structure may be bonded or welded to a seat tube of the bicycle frame and bonded or welded to a bottom bracket of the bicycle frame. The rear structure may also form an integral part of a frame moulded from a material such as carbon composite.

[008] Another preferred variant of the invention has the, front structure secured to a steerer tube and shaped to serve as a mudguard.

[009] According to a second aspect of the present invention there is provided a steerer fork for a vehicle comprising a steerer tube and a wheel mount to support a wheel wherein the wheel mount is supported to engage the wheel by a structure which serves as a mudguard.

[010] According to a further aspect of the present invention there is provided a vehicle frame comprising a frame part providing a head tube, seat tube and bottom bracket and a structure to support a rear wheel mount wherein the structure serves as a mudguard.

[011] In any case the structure may comprise an arcuate part sized and configured to fit over an arc of a ground engageable wheel when implemented in a bicycle.

One or more side strut parts will extend from at least one, and normally each side of the arch part to mount at least one dropout. The strut parts may be an unbroken side wall structures which may reduce the aerodynamic drag by providing an aerodynamic fairing.

[012] In the case of the front wheel structure a suspension mechanism may be provided to act between the steerer tube and the structure. The suspension mechanism is preferably provided by a telescopic strut extending from a steerer tube or crown and attached to the, or each, strut part. Alternatively the steerer tube may incorporate a telescopic strut to connect directly to the structure. Other forms of articulating linkage mechanisms may also be used.

[013] The structure may provide a brake mounting; a disc brake mounting is most conveniently provided. The structure may also provide a mounting for a derailleur.

[014] The structure may conveniently be adapted to provide mountings for lights or to incorporate lights. Generator elements may also be embedded in the structure to supply power to the lights. The structure may also be adapted by the inclusion of a compartment to provide a secure storage for a tool kit and/or security locks.

The structure may also be adapted to provide an integral luggage rack.

[015] Although the invention is primarily intended for use in a push bike, the use of the invention in a tricycle, quadricycle, power assisted man powered vehicles or motorised vehicles is also contemplated.

Brief description of the drawings

[016] Embodiments of a bicycle frame and forks constructed in accordance with the present invention will now be described, by way of example only, with reference to the following figures, in which: figure 1A is a NW isometric view of a first embodiment from below, figure 1 B is an enlarged detail NW view of the first embodiment, figure 1C is a SW isometric view of the first embodiment, figure 1 D is an enlarged detail on the SW isometric view of the first embodiment, figure 1 E is a detail of the first embodiment, figure 1 F is a variant of the first embodiment, figure 2A is a NW isometric view from above of a second embodiment, figure 2B is an enlarged detail of the NW isometric view of the second embodiment, and figure 3A is a side elevation of a third embodiment, figure 3B is an underside view of the third embodiment, figure 3C is an enlarged perspective view of the underside of the third embodiment.

Detailed description of drawings

[017] The first embodiment of the invention illustrated in figures lA-i D shows a bicycle frame and forks. In this case the term "forks" denotes the portion of the bicycle adapted to mount the front wheel and does not exclusively refer to the conventional assembly of steerer tube, crown and blades shown in the figures.

Referring to figures lA-iD a central frame assembly has down tube 1 slanting down to connect to a bottom bracket 2. A seat tube 3 is connected to the bottom bracket 2 from which it extends up to connect with a top tube 4. The top tube 4 extends forwards to connect with the head tube 5. The head tube connects to the down tube 1..

[018] What is shown as a central frame assembly is a substantially conventional push bike frame arrangement which serves to ensure that a saddle, bottom bracket and front wheel support (head tube) are maintained in a serviceable configuiation. This application is intended to cover all variations of the central frame assembly, including those which omit any of the frame members, i.e. the top tube, down tube or seat tube, or substitute more complex structures for the simple tubulai frame members.

[019] A steerer tube 6 is suppoited for rotation aiound its axis within the head tube 5 and descends to engage a front wheel support structure 7, the front wheel support structure 7 supports a pair of laterally spaced wheel mounts provided by dropouts 8. In the particular embodiment illustrated the structure 7 also suppoits a mounting for disc brake callipers 9. It will be appreciated that the structure may readily be adapted to support a hub brake. The structure 7 comprises an arcuate part 10 which arches over the dropouts 8 through an angle of substantially 180 degrees. The structure 7 may arch through angles other than 180 degrees, for example 90 degrees. The arcuate part 10 meets and engages the bottom of the steerer tube 6. The steerer tube may be secured to the arcuate part 10 by any suitable means including for example, welding or bonding, or in some designs may be an integrally moulded part. For example the arcuate pait 10 may be formed with a socket (not shown) to leceive the end of the steerer tube 6 to enhance the strength of the aforementioned securing means or to provide for a compiession joint, threaded joint oi othei mechanical fastening. The seculing means selected will depend on the nature of the materials used to form the steerer tube and the structure and the performance demanded of the bicycle to be built as is well understood by the skilled person. The structule and/or steeler tube may be made from any suitable material including, by way of example, any of: steel, aluminium, titanium or carbon fibre composite.

[020] The structure 7 includes opposing spaced side wall pads 11 which seive as struts and extend iadially from the dropouts 8 to side edges of the arcuate part 7.

Each side wall part 11 may be integrally formed with the arcuate part 10, for example in a moulding or pressing process or may be attached by welding, bonding or other conventional mechanical fastening means.

[021] Each side wall pad 11 in the first embodiment is an unbroken panel of uniform thickness, however the side wall may be pierced by windows or formed with regions of varied thickness in order to provide strength and stiffness in directions appropriate to demand (e.g. parallel to the wheel axle) and to remove unneeded material to minimise weight.

[022] The structure may be formed from metals, plastics, composite materials or combinations of such materials.

[023] A seat stay 12 is connected to and descends from the seat tube 3 to engage a rear wheel support structure 13. A chain stay 14 is connected to and extends from the bottom bracket 2 to engage the rear wheel support structure 13. The rear wheel support structure 13 supports a pair of rear wheel dropouts 15. The front and rear wheel dropouts 8 and 15 are generally similar structures each comprising a disc 16, which can be secured to the structure by adhesive bonding, welding or mechanical fastening. A slot 17 extends vertically in the disc 16 to receive a wheel axle. In some variants the drop out may be formed as an integral part of the structure. However, it is also contemplated that the drop out may be secured to to be removable and replaceable to effect a repair in the event of damage.

[024] The rear wheel support structure 13 comprises an arcuate pad 18 which has an arcuate cross section and arcs through an angle of 180 degrees. In variants of the embodiment the rear wheel support structure may arc through a greater or lesser angle, for example 90 degrees. A side wall part 19 extends, radially, one each from each drop out 15 to the corresponding lateral edge of the arcuate pad 18 and is sufficiently strong and stiff to serve as a strut supporting the weight of the bicycle and its payload in use. A disc brake calliper mount 20 is secured to a lower edge of one side wall part 19. The embodiment illustrated may be used for single speed or hub geared rear wheels. However, the side wall part opposite the disc brake mount may be provided with a derailleur hanger.

[025] The rear wheel support structure 13 will include a through slot 21 as shown in the detail of figure 1 E to accommodate a drive chain.

[026] Figure 1 F illustrates a variant of the first embodiment. In figure 1 F a basket 39 is moulded integrally onto the front support structure 7. Similarly a rear basket 40 is moulded onto the rear support structure 13. In a further variant each or either of the front and rear support structures 7 and 13 may have an integral adaptor (not shown, which cooperates with a corresponding adaptor formed one each into each of the front and rear baskets to removably mount the baskets onto the front and rear support structures 7 and 13.

[027] Figure 1 F also illustrates a storage box 41 moulded integrally with the rear structure 13 to extend between the seat tube and the rear structure 13. In use the storage box 41 may be closed by a cover (not shown).

[028] Figures 2A and 2B illustrate a second embodiment of the invention which differs from the first in the provision of a suspension arrangement acting between the steerer tube 5 and the structure 7. This is achieved by the provision of substantially conventional telescopic sprung and damped suspension blades 22 depending from a conventional fork crown 23. A sleeve 24 is formed onto the outer surface of each side wall 11. Each blade 22 is retained, one each, in each sleeve 24 whereby the structure 7 is secured to the steerer tube 5. The sleeves 24 are preferably moulded as an integral part of the structure.

[029] Alternative mechanisms for the provision of front wheel suspension may also be provided instead of the telescopic blades 22 including a telescopic head tube assembly.

[030] The rear wheel structure 13a is modified in the second embodiment to form an integral luggage rack 25, the luggage rack is a panel integral with the structure which extends horizontally across the top of the structure. The front structure may also be modified to carry luggage. Either or each of the front and rear structures may have mounting brackets to support running lights or may have running lights, preferably LED running lights incorporated into them. In a variant of this embodiment the luggage rack is formed separately from the structure. The luggage rack can thus be adapted for attachment to and detachment from the structure.

[031] Figures 3A to 3C illustrate an embodiment of the frame having provision for rear suspension. In this case the rear wheel support structure 13B is generally similar to either of the previously described structures but is not rigidly attached to the rest of the frame. The rear suspension structure 13B is provided with a first bracket 28 and a second bracket 29. The first bracket 28 is provided towards the front and bottom of the structure 1 3B while the second is provided relatively towards the top and front of the structure 1 3B. Each of the brackets 28 and 29 are provided to couple via a bearing with the rest of the frame. In this example the first bracket 28 may couple pivotally with a bearing 30 in a bearing mount 31 secured rigidly to the saddle tube and down tube parts of the frame trailing behind the bottom bracket 2. In variants of the rear suspension frame embodiment the lower bracket 28 may couple to the frame via a linkage. The second bracket 29 connects via a lever 32 mounted via a pivot 33 onto the downtube 3. The lever 33 is coupled via a pivot 34 to an upper end of a spring damper assembly 35. The spring damper assembly 35 depends from the pivot 34 to a mounting pivot 36 which is conveniently mounted on the bearing mount 31. This arrangement allows the structure 1 3B to pivot around the bearing 30 so that the unsuspended structure can more readily conform to undulation of the ground. Many other rear suspension geometries can be accommodated by the frame.

[032] In this embodiment each bracket 28 and 29 is provided by a pair of members, 28A and 29A spaced laterally as can best be seen in figure 3C where the suspension components are omitted for clarity.

[033] The view of the underside of the structure shown if figure 3C illustrates a "U" shaped reinforcement 37 which extends around the lower leading edge 38 of the structure. This reinforcement may have a solid or preferably tubular semi-circular section.

[034] It is to be understood that the individual features illustrated and described may reasonably be substituted between the described embodiments. Thus a luggage rack according to figure 3 may be provided on a suspension rear structure according to figure 4. The rear structure adapted for a hub gear in figure 1 may be replaced with a structure provided with derailleur hanger and a large chain slot 21 suitable for use with a derailleur transmission.

Claims

Claims 1. A frame and forks for a vehicle wherein either or both of front and rear dropouts are supported on a structure which serves as a mudguard.
2. A frame and forks for a vehicle according to claim 1 wherein at least the structure which serves as a mudguard also serves as a chain stay and a seat stay.
3. A frame and forks for a vehicle according to claim 2 wherein the structure comprises an arcuate part adapted to guard an arc of a wheel and a strut extending from the arcuate part to support a dropout.
4. A frame and forks for a vehicle according to claim 3 wherein the strut is provided by a side wall part.
5. A frame and forks for a vehicle according to any one of the preceding claims wherein the structure supports a disc brake mount.
6. A frame and forks for a vehicle according to any one of the preceding claims wherein the structure includes a mounting for a derailleur hanger.
7. A frame and forks for a vehicle according to any one of the preceding claims wherein the structure includes a luggage rack.
8. A frame and forks for a vehicle according to any one of the preceding claims wherein the structure includes brackets whereby the structure is mounted to the remaining frame parts by means of a sprung and damped suspension mechanism.III
9. A frame and forks for a vehicle according to claim 1 wherein a steerer tube is provided on which the structure is mounted.
10. A frame and forks for a vehicle according to claim 9 wherein the suspension mechanism comprises a telescopic strut.
11. A frame and forks for a vehicle according to claim 10 wherein the telescopic strut engages the structure via a sleeve formed on the side wall.
12. A frame and forks for a vehicle according to any of claims 9 to 11 wherein the structule is adapted to foim a luggage iack.
13. A frame for a vehicle wherein rear dropouts are supported on a structure which serves as a mudguard.
14. A frame for a vehicle according to claim 13 wherein at least the structure which serves as a mudguard also serves as a chain stay and a seat stay.
15. A frame for a vehicle according to claim 13 or 14 wherein the structure comprises an arcuate part adapted to envelop an arc of a wheel and a strut extending from the arcuate part to support a dropout.
16. A frame for a vehicle according to claim 15 wheiein the strut is provided by a side wall part.
17. A frame for a vehicle according to any one of claims 13 to 16 wherein the structure supports a disc brake mount.
18. A frame for a vehicle according to any one of claims 13 to 17 wherein the structure includes a mounting for a derailleur hanger.
19. A frame for a vehicle according to any one of the preceding claims wherein the structure includes a luggage rack.
20. Steerer forks for a vehicle comprising a steerer tube and a structure serving as a mudguard, wherein the structure supports a dropout to mount a front wheel.
21. Steerer forks for a vehicle according to claim 20 wherein the structure comprises an arcuate part adapted to guard an arc of a wheel and a strut extending from the arcuate part to support the dropout.
22. Steerer forks for a vehicle according to claim 21 wherein the suspension mechanism comprises a telescopic strut.
23. Steerer forks for a vehicle according to claim 22 wherein the telescopic strut engages the structure via a sleeve formed on the side wall.
24. Steerer forks for a vehicle according to any of claims 20 to 23 wherein the structure is adapted to form a luggage rack.
25. A frame and steerer forks according to any one of the preceding claims wherein the vehicle is one of a bicycle, a tricycle or a quad.
26. A bicycle, a tricycle or a quad comprising a frame according to any one of claim 13 to 19.
27. A bicycle, a tricycle or a quad comprising forks according to any one of claims 19 to 24.
28. A frame and forks for a vehicle as herein described with iefeience to the accompanying figures.Claims 1.A frame and forks for a vehicle having either or both of front and rear drop outs wherein either or both of the front and rear dropouts are supported on a structure which serves as a mudguard and the structure supports a disc brake mount.2. A frame and forks for a vehicle according to claim 1 wherein at least the structure which serves as a mudguard also serves as a chain stay and a seat stay.3. A frame and forks for a vehicle according to claim 2 wherein the structure comprises an arcuate part adapted to guard an arc of a wheel and a strut extending from the arcuate part to support a dropout.4. A frame and forks for a vehicle according to claim 3 wherein the strut is provided by a side wall part.LO (45. A frame and forks for a vehicle according to any one of the preceding claims wherein the structure includes a mounting for a derailleur hanger.6. A frame and forks for a vehicle according to any one of the preceding claims wherein the structure includes a luggage rack.7. A frame and forks for a vehicle according to any one of the preceding claims wherein the structure includes brackets whereby the structure is mounted to the remaining frame parts by means of a sprung and damped suspension mechanism.8. A frame and forks for a vehicle according to claim 1 wherein a steerer tube is provided on which the structure is mounted.9. A frame and forks for a vehicle according to claim 7 wherein the suspension mechanism comprises a telescopic strut.10. A frame and forks for a vehicle according to claim 9 wherein the telescopic strut engages the structure via a sleeve formed on the side wall.11. A frame and forks for a vehicle according to any of claims 8 to 10 wherein the structure is adapted to form a luggage rack. 12.A frame for a vehicle having rear dropouts wherein the rear dropouts are 0 supported on a structure which serves as a mudguard and the structure supports LI) a disc brake mount. (413. A frame for a vehicle according to claim 12 wherein at least the structure which serves as a mudguard also serves as a chain stay and a seat stay.14. A frame for a vehicle according to claim 12 or 13 wherein the structure comprises an arcuate part adapted to envelop an arc of a wheel and a strut extending from the arcuate part to support a dropout.15. A frame for a vehicle according to claim 14 wherein the strut is provided by a side wall part.16. A frame for a vehicle according to any one of claims 12 to 15 wherein the structure includes a mounting for a derailleur hanger.17. A frame for a vehicle according to any one of the preceding claims wherein the structure includes a luggage rack. 18.Steerer forks for a vehicle comprising a steerer tube, front dropouts and a structure serving as a mudguard; wherein the structure supports: a dropout to mount a front wheel and * a disc brake mount.0 19. Steerer forks for a vehicle according to claim 18 wherein the structure comprises an arcuate part adapted to guard an arc of a wheel and a strut extending from the arcuate pad to support the dropout.20. Steerer forks for a vehicle according to claim 19 wherein the suspension mechanism comprises a telescopic strut.21. Steerer forks for a vehicle according to claim 20 wherein the telescopic strut engages the structure via a sleeve formed on the side wall.22. Steerer forks for a vehicle according to any of claims 18 to 21 wherein the structure is adapted to form a luggage rack.23. A frame and steerer forks according to any one of the preceding claims wherein the vehicle is one of a bicycle, a tricycle or a quad.24. A bicycle, a tricycle or a quad comprising a frame according to any one of claim 12 to 17.25. A bicycle, a tricycle or a quad comprising forks according to any one of claims 17 to 22.26. A frame and forks for a vehicle as herein described with reference to the accompanying figures.LO (4