GB2278814A

GB2278814A - A bicycle frame

Info

Publication number: GB2278814A
Application number: GB9311565A
Authority: GB
Inventors: Christopher James Drake; Kevin Neville Hodges; Sebastian Kaye Barnett
Original assignee: Moore Large & Co Ltd; Revolver Marketing Ltd
Current assignee: Moore Large & Co Ltd; Revolver Marketing Ltd
Priority date: 1993-06-04
Filing date: 1993-06-04
Publication date: 1994-12-14
Anticipated expiration: 2013-06-04
Also published as: GB2278814B; GB9311565D0; WO1994029162A1; AU6802894A

Abstract

The bicycle frame has an inner, structural frame portion 1 and an outer, casing portion 2, 3 located extemally of the frame portion. The casing portion preferably substantially surrounds at least part of the frame portion. The casing portion can easily be styled to a desired shape without the structural frame portion being altered. The casing may provide some of the structural strength of the frame, and also may be provided with a variety of finishes to enhance safety. <IMAGE>

Description

BICYCLE The present invention relates to a bicycle.

Bicycle frames, which connect the wheels of a bicycle and to which are attached equipment such as saddles and pedals, are conventionally made of tubing or other similar material which provides the structural strength of the frame and defines the exterior surface of the bicycle's frame region. This arrangement has several disadvantages. The exterior of the bicycle cannot easily be styled to a desired shape (either for aerodynamic reasons or to follow current fashions) because to do so would require the frame itself to be shaped. Due to considerations of weight, this is only possible if the frame is made of a (typically expensive) material having a good strength-to-weight ratio. Also, the external surface area of the frame is relatively small so there is little room for decorative patterns or advertising to be applied to the frame. Also, most frames are made of metal members joined together and work is needed after joining has taken place to finish the exterior of such frames by smoothing the joints and removing rust; otherwise the joints are unsightly and impair the bicycle's aerodynamic qualities.

According to the present invention there is provided a bicycle comprising an inner, structural frame portion and an outer, casing portion located externally of the frame portion.

This arrangement allows the disadvantages mentioned above to be overcome. The casing portion can easily be styled to a desired shape without any need to alter the structural frame portion. For example, the casing portion can be styled as an aerodynamic fairing around the frame portion. Alternatively, the casing portion can be styled to an attractive design, for example to resemble the frame of a bicycle made of expensive, high strength materials or to simulate apparatus such as suspension on the bicycle. The casing portion can easily be styled to include relatively large exterior surface portions, preferably presenting substantially vertical surfaces, to receive patterns or advertising material.

Preferably, parts of the frame portion are substantially surrounded by the casing portion and encased by it to prevent them being exposed once the bicycle is assembled.

Such parts may be left in an unfinished or semi-finished state without detracting from the bicycle's aesthetic or aerodynamic properties. Thus the cost of finishing the frame portion is reduced. Similarly, the casing portion can cover the bolts, bolt holes, etc which are normally present on a bicycle. This has similar aesthetic and aerodynamic advantages.

The casing portion may surround (or substantially surround) all of the frame portion, including, for example, the bicycle's front and/or rear forks. The majority of the frame portion may be encased in a single cavity of the casing portion or alternatively each member of the frame portion may be received in an individual channel inside the casing portion.

The casing portion preferably comprises two complementary casing members which are located on opposite sides of the frame portion and are joined together or to the frame portion. Additional casing members may also be used.

The casing portion suitably includes an exterior wall and interior spacing nibs for spacing the exterior wall from the frame portion.

The present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side view of a bicycle according to the invention; Figure 2 is an exploded perspective view of part of the bicycle of Figure 1; and Figure 3 is a side view of a second embodiment of a bicycle according to the invention.

Figures 1 and 2 show a bicycle having an inner frame 1 and outer casings 2 and 3. When assembled, as shown in Figure 1, the casings surround parts of the inner frame and their outer walls 21,31 define the majority of the exterior surface of the bicycle's frame region.

The frame 1 is made of steel tubing welded together in the conventional way. It includes flat-sided rear stays 12,13 which meet the seat tube 14 near its upper end and are supported by tubular support stays 15,16 which converge downward from the rear stays to the seat tube 14. Those parts of the frame which are to be encased by the casings are left unfinished or semi-finished. In the embodiments of Figures 1 and 3 parts of the front forks 11 and the rear stays 12,13 are not encased and these must be finished in the normal way. However, all of the frame could be encased to avoid the need for any such finishing work. Where the chain and gears are encased the risk of the rider being dirtied by oil from the chain is reduced.

The casings 2,3 are made of plastics material (for example ABS, styrene or polypropylene) injection moulded or vacuum formed to the required shape. Such casings can be manufactured relatively cheaply. The casings are relatively light and resilient and provide a smooth, aerodynamic exterior surface to the bicycle. This is easier for the user to clean than the complex shapes of conventional bicycles. As shown in Figure 2, the casings are of complementary shapes and are joined around the frame with self-tapping screws 4. These pass through bores 22 in casing 2 and into projections 32 in casing 3 to draw the casings together around the frame as the screws are tightened. Alternatively, the casing members could be snap-fitted together. Casing 3 includes nibs 33 which bear against the exterior of the frame when the casing is assembled to space the outer walls 21,31 of the casing away from the frame. The nibs 33 mate with cooperating holes in casing 2 to ensure correct alignment of the casings and a flush fit at the meeting edges of the casings when they are assembled.

Webs 23,34 are provided for aesthetic reasons and to strengthen the casings. Ports are provided in the assembled casing to allow equipment such as, for example, the crank shaft 6, the seat post 7 and brake cables to pass through the casing. Apart from these ports the interior of the casing is substantially sealed (to protect the frame inside) except for a drain hole 24 and a bore 35 which allows access to the seat-post locking bolt 8 to allow the height of the saddle to be adjusted without the casing being removed. Thus, the casing protects the encased parts of the frame from corrosion.

In the embodiment of Figure 1 each tube of the frame passes through an individual channel in the assembled casing, and a central opening 5 is defined through the casing. In the embodiment of Figure 3 the assembled casing defines a single interior cavity which receives the majority of the frame.

Secondary casings 9 are provided around the front forks.

These may be styled aesthetically, for example to simulate suspension apparatus, or aerodynamically.

The casings provide relatively large external surfaces, in particular particularly substantially vertical surfaces, to which may be applied decorative patterns or advertisements. The casings may be made of transparent material to protect decoration (such as decals or paintwork) applied to the frame itself whilst allowing the decoration to be seen. The casings may have reflective or pearlescent portions affixed to their exterior surfaces or moulded into them. These increase the safety of the bicycle by making it more visible, especially in the dark.

The casings may be a structural element of the bicycle, allowing the size, and therefore weight, of the tubes of the frame to be reduced.

Claims

1. A bicycle comprising an inner, structural frame portion and an outer, casing portion located externally of the frame portion.

2. A bicycle as claimed in claim 1, wherein the casing portion substantially surrounds at least part of the frame portion.

3. A bicycle as claimed in claim 1, wherein the casing portion substantially surrounds all of the frame portion.

4. A bicycle as claimed in any preceding claim, wherein a plurality of channels are defined internally of the casing portion for receiving parts of the frame portion.

5. A bicycle as claimed in any of claims 1 to 3, wherein the casing portion defines a single interior cavity for receiving the majority of the frame portion.

6. A bicycle as claimed in any preceding claim, wherein the casing portion comprises two complementary casing members, located on opposite sides of the frame portion.

7. A bicycle as claimed in claim 6, wherein the casing members comprise an exterior wall and a plurality of nibs provided on the interior surface of the wall to space the wall away from the frame portion.

8. A bicycle as claimed in any preceding claim, wherein the exterior surface of the casing portion is configured to have the appearance of a bicycle frame.

9. A bicycle as claimed in any preceding claim, wherein the exterior surface of the casing portion includes at least one relatively large, substantially vertical portion.

10. A bicycle as claimed in any preceding claim, wherein at least part of the casing portion is transparent.

11. A bicycle as claimed in any preceding claim, wherein the exterior surface of the casing portion includes a reflective or pearlescent portion.

12. A bicycle as claimed in any preceding claim, wherein at least part of the frame portion is unfinished or semifinished.

13. A bicycle substantially as herein described with reference to the accompanying drawings.

14. A casing portion for a bicycle, having an exterior surface for defining the exterior surface of at least part of the bicycle and an inner surface configured to engage at least part of the frame of the bicycle.

15. A casing portion as claimed in claim 14, wherein the casing portion substantially surrounds at least part of the frame.

16. A casing portion of a bicycle as claimed in any of claims 1 to 13.

17. A casing portion substantially as herein described with reference to the accompanying drawings.