WO2006131742A1

WO2006131742A1 - Foldable cycle with spokeless wheels

Info

Publication number: WO2006131742A1
Application number: PCT/GB2006/002104
Authority: WO
Inventors: Mark Sinclair
Original assignee: Mark Sinclair
Priority date: 2005-06-06
Filing date: 2006-06-06
Publication date: 2006-12-14
Also published as: GB2426962A; GB0511482D0

Abstract

A foldable cycle comprising a frame (2) and front and rear wheels (6, 7) has a front frame section (4), a central frame section (3) and a rear frame section (5). The wheels (6, 7) are spokeless and are mounted via their rims (61) in wheelguides (8, 9). A first hinge (10) allows rotation of the front frame section (4) and the front wheel (6) so that the front wheel can be folded around to the side of the central frame member (3). Likewise, a second hinge (11) allows rotation of the rear frame section (5) and the rear wheel (7) so that the rear wheel (7) can be folded around to the side of the central frame member (3).

Description

FOLDABLE CYCLE WITH SPOKELESS WHEELS

The present invention relates to foldable cycles.

A foldable bicycle is disclosed in GB 2287438 comprising a frame which includes a front frame part and a rear frame part rotatably connected to one another via a hinge for relative rotation about a vertical axis. A rear spoked wheel is connected to the rear frame part and a front spoked wheel is connected to the front frame part.

US 6224080 discloses a spokeless bicycle system, wherein front and rear spokeless wheels are rotatably mounted via their rims to respective front and rear brackets. The bicycle frame is rigid and not foldable.

Traditional folding bicycles have small wheels compared to non-folding bicycles, which can lead to a reduced ride quality, and less flexibility for the bike to handle varying terrains. Traditional non-folding bikes have large wheels, thus avoiding this problem, but lack the flexibility of a folding bike to be carried on various types of public transport.

The present invention provides a foldable cycle comprising a frame and front and rear wheels, at least one of which is spokeless, the front and/or rear wheel being mounted on a portion of the frame which is foldable about an axis into a folded position.

Advantageously, the invention enables a design of the cycle which combines large wheels with a foldable frame. Further, by using spokeless wheels it is possible for other components of the cycle in the folded position to engage the space defined by the wheel, which would otherwise be occupied by spokes, thereby allowing the overall size of the folded bike to be minimized. These components may include the pedals, the cranks and the front drive sprockets for instance. Advantageously the frame can comprise a central frame section which can comprise a single cross bar, thereby reducing structural complexity and weight.

Further advantageously, the frame can comprise a front frame section for holding the front wheel, a central frame section and a rear frame section for holding the rear wheel. The front and rear frame sections can be hinged to the bike so that when it is folded, the front and rear wheels and the central frame member are all aligned side by side, giving a particularly compact construction.

The present invention also provides a frame for a foldable cycle comprising a rear frame section for holding a rear wheel a central frame section, and a front frame section for holding a front wheel, the rear frame section being foldable relative to the central frame section about a first axis, to a position on one side of the central frame section, the front frame section being foldable relative to a central frame section about a second axis to a position on the other side of the central frame section.

There now follows a detailed description of an embodiment of the invention with reference to the accompanying drawings in which:

Fig. 1 is a side elevational view of the cycle;

Figs. 2 A to 2E are plan views showing a folding sequence of the cycle;

Fig. 3 is a side view of the cycle when folded;

Fig. 4 is a close-up side view of a drive mechanism of the cycle;

Fig. 5 is a sectional view of a wheel and a wheelguide; Fig. 6 is a plan view of the cycle when folded;

Fig. 7 is a sectional view of the wheels and frame when the cycle is folded.

In Fig. 1 there is shown a foldable cycle with a frame 2 comprising a central frame section 3, a front frame section 4 and a rear frame section 5. The central frame section 3 comprises a single load-bearing cross bar, unlike in traditional cycle frames where normally, at least two bars or tubes are need to give sufficient strength and rigidity to the cycle e.g. the standard diamond shape frame. The frame 2 is optionally made from Aluminium. A front spokeless wheel 6 is connected to the front frame section 4 by a front wheel guide 8 in which the front wheel is slidably mounted. Likewise, a rear spokeless wheel 7 is slidably mounted in a rear wheel guide 9 connected to the rear frame section 5. The wheel guides 8,9 allows sliding of the spokeless wheels in a circumferential direction, so the cycle can be moved along in the normal manner.

The front 4 and rear 5 frame sections respectively include a front hinge 10 and rear hinge 11. The hinges 10, 11 allow the cycle to be folded. An advantageous compactness is achieved by the positioning and orientation of the hinges to minimise the volume of the folded cycle, wherein the hinges 10, 11 are located close to or at the points where the front frame section 4 meets the central frame section 3 and the rear frame sections meets the central frame section. The front, rear and central frame sections are each formed with a part-circular arc shape, as are the wheel guides 8, 9, such that when folded, the wheel guides 8, 9 line up with the central frame section 3 to save space. The hinges 10, 11 define folding axes 12, 13 which are generally vertical when the cycle is in an upright position.

In an alternative embodiment not shown in the drawings, the rearward end of the cycle is of the same construction as a standard mountain bike, i.e. having a rear spoked wheel connected to a standard frame shape, but with a spokeless front wheel connected to a front frame section which is hinged to be foldable relative to the rest of the frame.

Mounted on the central frame section 3 is a seat tube 16 for receiving a seat post 15 to which is connected a saddle 18. The seat post 15 and saddle 18 can be selected from bike parts available as standard.

A handlebar stem 14 is mounted on the front frame section 4. At the top of the handlebar stem 14 is a handlebar 17, which can be folded relatively to the handlebar stem to save space when the cycle is folded. The handlebar 17 can include a hinge at the top of the stem 14 to allow folding away of the handlebar 17. The front wheelguide 8 is movable relative to the front frame section 4, so that the steering angle of the front wheel 6 can be adjusted to steer the cycle. In this respect, the handlebar 17 is connected to the front wheelguide 8 and is operable to effect rotation thereof. The wheelguide 8 is rotatably connected at its front end region to the front end region of the front frame section 4.

Instead of or as well as having a foldable handlebar 17, it is envisaged that the handlebar stern 14 could be retracted through the front frame section 4 when the cycle is folded.

The front, central and rear frame sections can each comprise circular arc portions having the same radius of curvature. In the embodiment shown in Fig. 1, the wheelguides 8, 9 have the same radius of curvature as the central frame section, which means that in the folded position they overlap one another to minimize the size of the folded cycle.

Figs. 2A to 2E show a folding sequence of the cycle, Fig. 2A showing the cycle in the unfolded, ready to use configuration. To begin folding the cycle, the user unlocks locking means (not shown) associated with each hinge 10, 11, to allow rotation of the front and rear frame sections with the corresponding wheels 6, 7 about the axes 12, 13. In the example shown, the front frame section 4 is to be folded to the right, and in this case, the hinge 10 is situated on the right hand side of the cycle, to allow substantially 180° of rotation of the front frame section 4, to bring the front wheel into alignment with the central frame member 3. Likewise, the rear hinge 11 is provided on the left hand side of the cycle to allow the rear wheel 7 to fold into its folded position without being hindered by the front wheel 6 or the other frame sections, and to allow substantially 180° of rotation.

In Fig. 2B, the rear wheel 7 has been folded to an extent sufficient to disengage it from a drive member 46, described in more detail with reference to Fig. 4.

At the end of the sequence shown in Fig. 2E, the front and rear frame sections and the corresponding wheels are folded around to the side of the central frame member and He against the central frame member 3 and it can be seen that the length of the folded cycle is approximately one third of the length of the unfolded cycle.

Fig. 3 shows the folded position of the cycle from the side. The front and rear wheel guides 8 and 9 are substantially aligned with the central frame section 3, whilst the front and rear frame sections 4 and 5 are situated above the central frame member 3. The seat post 15 has been fully pushed into the seat tube 16, and the handlebar stem 14 has been fully retracted. The central frame section 3 includes at its rear end region a leg 30 with a bottom bracket 33 receiving a spindle (not shown) and a crank 35. A pedal 36 is rotatably connected to the radially outer end of the crank 35. The leg 30 comprises a first downwardly extending portion 31 and a forwardly extending portion 32 with the bottom bracket being disposed at the front end region of the forwardly extending portion 32. This construction allows a relative positioning of the saddle 18, the bottom bracket 33 and the handlebar 17 which gives an optimum riding position. Fig. 4 is a close-up view of the drive mechanism of the cycle, including the pedal 36, the crank 35, the bottom bracket 33 and the forwardly extending portion 32. A front set of sprockets 41, 42, 43 is rotatably mounted at the bottom bracket 33 to be driven by the pedal 36. A chain 44 drivingly connects the front sprockets to a rear set of sprockets 45. The rear set of sprockets 45 is supported by the leg 30, and in particular is mounted on a rearwardly extending portion 37 of the leg 30. Mounted adjacent the rear set of sprockets 45 is a drive member 46, rotationally fast with the rear set of sprockets. When the bike is in the unfolded position, as in Fig. 4, the drive member 46 engages the rim 61 of the rear wheel 7, such that rotation of the rear sprockets 45 drives the rear wheel 7. The drive member 46 can engage the rim 61 frictionally, or by any other suitable means, e.g. by means of teeth provided on the drive member 46 and corresponding teeth on the rim 61 for meshing with the teeth on the drive member 46. The drive member 46 can comprise one or more discs arranged for engaging the rim 61. Standard front and rear derailleur systems (not shown) are used to change gear.

Fig. 5 shows a cross-section through the front or rear wheelguide 8,9 with the front or rear wheel 6,7 extending through it. The wheel comprises the rim 61, with a tyre 52 applied thereon and an inner tube 51 fitted in the tyre 52. The wheel includes a ridge 53 on each side, the ridges 53 engaging into corresponding channels 57 in the interior of the wheelguide 8,9. The interior profile of the wheelguides 8,9 includes a thicker part 56, in which the channels 57 are formed, to provide enough structural strength to cope with the forces occurring between the wheel and wheelguide. Inside each channel 57 is a series of bearings allowing substantially unrestricted motion of the ridges 53 relative to the channels 57, thereby allowing rotation of the wheel as a whole. Between the rim 61 and a thinner part 58 of the wheelguide 8,9 there is a cavity 55. In one embodiment not shown in the drawings, the wheelguide can be opened to allow changing of the wheel/tyre/inner tube and to allow cleaning of the interior of the wheelguides. In this respect the wheelguide 8,9 can comprise a pair of shell portions which can be firmly held together. In order to cope without having spokes, the wheel rim 61 is much thicker than a normal wheel rim, to ensure it has sufficient strength. The triangular profile of the rim 61 also lends to its strength. To keep weight down, the rim 61 can be made from Aluminium and this can be done by an extrusion process.

Fig. 6 is a plan cross-sectional view of the cycle in the folded position, showing the front wheel 6 folded to the right and the rear wheel 7 folded to the left. The rear sprockets 45 and the drive member 46 protrude from the rear of the cycle. The front sprockets 41, 42, 43 are disposed in the space defined radially inside the rim of one of the wheels, in this case the front wheel 6. The right pedal 36 and the right crank 35 are located inside the front wheel 6 and the left pedal 36 and left crank 35 are located in the rear wheel 7. With traditional wheels, this would not be possible because the spokes and the hub would be in the way. The pedals 35 are also foldable so as not to protrude laterally from the wheels of the cycle when folded. The leg 30, in particular the downwardly extending portion 31, the forwardly extending portion 32 and the bottom bracket 33, can also occupy the space defined radially inside the wheel rims, depending on their width. If their width is greater that the lateral separation of the wheel rims, then they will engage the space defined radially within each rim.

Fig. 7 shows in detail a cross-section of the wheelguides 8,9 folded against the central frame section 3. The sides of the central frame section 3 are indented with a circular arc shape profile 71, thus allowing the wheelguides 8,9 to sit partially within the central frame section 3, thereby reducing the width of the cycle when folded. The leg 30 can also have an indented profile, or can have a circular profile.

To make maintenance of the cycle as user friendly as possible, the cycle utilises where practicable spare parts that are commonly available as standard. This also reduces manufacture and production costs, since the products already exist within the market place. It also allows the consumer to have a varied choice of which components they wish to purchase within an existing market place. For instance, the wheel rims can be designed to accommodate standard inner tubes and tires, the frame can be designed to accommodate standard saddle and saddle posts, standard handlebars and steering mechanisms, standard bottom hub, cranks and pedals, and standard brakes, pads, levers, cables etc.

The cycle can be made with a bag to allow easy carrying of the folded cycle, and to avoid oil and dirt from the cycle being transferred to the person carrying the cycle. Alternatively, due to the construction of the cycle, it is possible to wheel it along when in the folded position, and the seat can be used as a handle in this respect. A mounting frame can be provided to mount the cycle on a wall for storage and/or display purposes.

Claims

CLAIMS:

1. A frame for a foldable cycle comprising

a rear frame section for holding a real^* wheel

a central frame section, and

a front frame section for holding a front wheel,

the rear frame section being foldable relative to the central frame section about a first axis, to a position on one side of the central frame section, the front frame section being foldable relative to a central frame section about a second axis to a position on the other side of the central frame section.

2. A frame according to claim 1, wherein the central frame section comprises a single cross bar.

3. A frame according to claim 1 or 2, wherein each frame section comprises a part-circular arc portion having substantially the same radius of curvature as each other.

4. A frame according to any one of claims 1 to 3, wherein at least the central frame section comprises tubing of a generally circular cross section, with arcuate indentation channels along its sides.

5. A frame according to any one of claims 1 to 4, wherein the frame is made from Aluminium.

6. A foldable cycle comprising a frame and front and rear wheels, at least one of which is spokeless, the front and/or rear wheel being mounted on a portion of the frame which is foldable about an axis into a folded position.

7. A foldable cycle according to claim 6, wherein in the folded position, a component of the cycle engages the space defined radially inside a rim of the or each spokeless wheel.

8. A foldable cycle according to claim 7, wherein the component which engages the space defined radially inside the rim comprises any one or more of a pedal, a pedal crank and a front sprockets.

9. A foldable cycle according to any one of claims 6 to 8, wherein the front wheel is spokeless.

10. A foldable cycle according to any one of claims 6 to 9, wherein the rear wheel is spokeless.

11. A foldable cycle according to any one of claims 6 to 10, wherein the axis is substantially vertical when the cycle is in a generally upright position.

12. A foldable cycle according to any one of claims 6 to 11, wherein the frame comprises a hinge to allow folding of the frame about the axis.

13. A foldable cycle according to claim 12, wherein the hinge is mounted on the side of the frame.

14. A foldable cycle according to any one of claims 6 to 13, wherein the frame comprises a front frame section for holding the front wheel, a central frame section and a rear frame section for holding the rear wheel, the portion of the frame which is foldable comprising the front frame section and/or rear frame section.

15. A foldable cycle according to claim 14, wherein the front frame section comprises a front wheelguide in which a spokeless wheel is rotatably mounted via its rim.

16. A foldable cycle according to claim 14 or 15, wherein the rear frame section comprises a rear wheelguide in which a spokeless wheel is rotatably mounted via its rim.

17. A foldable cycle according to claim 16, wherein the front and rear wheelguards each comprise a pair of housing shell portions fixable together to hold a spokeless wheel firmly therein.

18. A foldable cycle according to any one of claims 14 to 17, wherein the central frame section comprises a single cross bar.

19. A foldable cycle according to any one of claims 14 to 18, wherein each frame section comprises a part-circular arc portion having substantially the same radius of curvature as each other.

20. A foldable cycle according to any one of claims 14 to 19, wherein at least the central frame section comprises tubing of a generally circular cross-section with arcuate indented channels along its sides.

21. A foldable cycle according to any one of claims 6 to 20, wherein the frame is made from Aluminium.