GB2361463A - Bicycle frame - Google Patents

Abstract

The frame comprises upper and lower longitudinal members 1, 2, each of a generally rectangular cross-section and comprising two interlocking shaped parts having several layers of carbon fibre with a centre membrane of beechwood or aluminium alloy, the parts being fixed together by cap screws. The two members are connected together by a carbon fibre or alloy frame member 3 carrying a speed change mechanism and rear suspension strut. For a racing bicycle, the members 1, 2 are curved mirror images of each other. Tie rods 9, 10 can extend from a rear end of the upper member 1 to a rear wheel axle. The frame enables selective location of a saddle and pedal crank.

Description

2361463 NEW ALL PURPOSE BICYCLE FRAME.

This invention relates to a new man powered bicycle frame and includes designs for:- 1 An endurance racing frame.

2 A mans frame.

3 A bike with sprung rear suspension.

These bicycle frames include a new design and construction method and the complete bike involves a new chain drive arrangement to the rear wheel, a new rear wheel spindle and rachet layout, a new front forks and handle bar design and disc brakes on both wheels with fixed locations and, the saddle position can vary both horizontally and vertically with slight adjustments on pedal position with the aim to satisfy more closely variations in human sizes.

DESCRIPTION

This description will primarily relate to the racing version but equally applies to all other versions although frame units will vary between versions. All parts are made from precision mechanical engineered parts and include various purchased items such as tyres, bearing etc., and include non-ferrous castings, laminations, composite materials, carbon fibre/carbon fibre re-inforced plastic, tube bending, sheet metal work and hydraulic oil/braking fluid.

The whole bicycle covers 25 sheets but these bicycle frames are illustrated on 7 sheets, sheets 1 to 6 and sht.2A.

Sheet I shows a full picture general purpose mans bike.

Sheet 2 shows the complete racing frame.

Sheet 2A shows constructional section of part 1, 2 & 3.

Sheet 3 shows a side view of mans frame.

Sheet 4 shows a plan view of bike.

Sheet 5 shows a mans frame with rear suspension.

Sheet 6 shows a womans bike frame.

February 99 New all purpose bicycle parts GENERAL The basic concept was to create a frame using lightweight materials such as carbon fibre which is not constrained by existing parameters of shape, and to combine this with new mechanics with the idea to avoid the existing chain drive arrangement which applies currently to most racing and other bikes relying on the use of a thin flexible chain drive to the back wheel.

It is expected that this new arrangement with new mechanics will be more efficient although it uses more moving parts and thus more bike weight but it is hoped the new frame design and use of modern materials will counter this in part although, it is believed that extra weight of rotational masses is not necessarily a bad thing as it creates extra kinetic energy like a flywheel and thus will overcome sudden head-winds easier than the current racing bikes thus reducing the need to re:accelerate.

The frame shape is naturally streamlined as shown with extra streamlining and chain protection (when allowed) from covers which also shrouds the top of the rear wheel reducing drag from the fast moving upper part of the tyre. Similar front wheel streamlining with guards is possible.

This application relates to new bicycle frames as illustrated, a mans frame involves a change of shape to the upper frame member 1 whereby the shape follows around frame member 3 and then curves into a staight line and at right angles to item 4 joining at the top, see sheet 3.

FRAME In all bike versions the frame design and construction is non-conventional in that each cross section when made up is approximately rectangular in shape. The basic construction is as shown on the 7 sheets, item 1,2 and 3 being the main frame members with additional parts 4, 9 and 10 or 4 and 12.

Each frame member combines a top & bottom horizontally split interlocking section of several layers of carbon fibre formed to the shapes shown on sheet 2A Fig.1 (which shows a section through the frame members 1 & 2) with a centre membrane of European Beech or other suitable material and the whole assembly held in place with central cap screws as shown, item 20. Fig.2 gives a section through item 12 and Fig.3 shows a typical section through the centre member 3.

February 99 New all purpose bicycle parts The lower frame member item 2 is slightly larger in section than item 1 and the central bolts 20 can be used to hold other items against the frame or hollow bolts can be employed. Sheet 2 shows the frame design for the racing bike and the thin front forks mounting tube part 4 is held in place with 4 vertical screwed rods and caps, this locks items 1 and 2 in place plus the centre member 3, which carries the gear speed change mechanizm, locates and stresses frame members 1 & 2 apart using tie rods 9 & 10.

The top frame member is shaped to clear the riders knees if necessary and at the rear wheel end a luggage rack is used for securing items 9 & 10. Bracket 5 forms rear wheel centre C on lower member 12 with or without rear suspension.

The lower swinging arm frame member 12 on sheet 5 and 6 pivots from an offset point on pedal crank casting item 8 and this casting also provides a maximum extension stop for the strut part 15 which pivots from centre frame member 3.

The central frame member 3 is made up of three shaped wooden parts or other material, one top and bottom with a central curved beam of wood linking the two all of European Beech with thin steel supports top and bottom and all shrouded in a carbon fibre cover.

February 99 New all purpose bicycle parts

Claims (1)

1. 2a A bicycle frame of near rectangular shape and method of construction wherein, each frame member combines a top & bottom interlocking section of several layers of carbon fibre formed to the shapes shown on sheet 2A with a centre membrane of rectangular shape of European Beech or aluminium alloy or other suitable material and the whole assembly held in place with central cap screws as shown.

   2b A bicycle frame of near rectangular shape and method of construction as claimed 2a wherein, both main frame members 1 and 2 are spaced apart with a carbon fibre or alloy frame member 3 which in-turn carries the speed change mechanism and rear suspension strut item 15 sheet 5 and 6.

   2c A bicycle frame of near rectangular shape and method of construction as claimed in claim 2a & 2b wherein, the top frame member item 1 of the racing frame sheet 2 is curved upward as a mirror immage of the lower member for simplicity of construction and natural streamlining. Frame members are constructed in curves for optimum strength and rigidity.

   2d A bicycle frame of near rectangular shape and method of construction as claimed in 2b & 2c wherein, the rectangular design and bolting method allow key parts such as saddle and pedal crank if necessary, to be attached at alternative places to gain an optimum location for each rider.

   February 99