GB2516129A

GB2516129A - A disc brake for motor cycle

Info

Publication number: GB2516129A
Application number: GB1322148.6A
Authority: GB
Inventors: Malcolm Stewart Chapman
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-05-31
Filing date: 2013-12-13
Publication date: 2015-01-14
Also published as: GB2516531A; GB201407762D0; GB201322148D0

Abstract

An automotive disc brake for motorcycles which consist of a disc A and calliper C arrangement, wherein, the disc is fastened to the wheel J via its outer perimeter B and the calliper is located on the inner perimeter of the disc. The disc may preferably be either single or dual and the calliper may be singular or plural. The disc and calliper arrangement also provides a means of heat displacement away from the disc.

Description

V

A DISC BRAKE FOR MOTOR CYCLE

An automotive disc brake with single or dual discs and multi calliper arrangements for motor cycles

BACKGROUND

When compared to a motor vehicle with four wheels, a motor cycle has fewer options for the mounting of brake callipers. A vehicle with more than two wheels generally has a hub carrier which lends itself to the location of callipers around the perimeter of the disc. A motor cycle has only the forks, and as discs on high performance machines have grown in diameter, the attachment of the calliper makes demands in terms of strength, rigidity and weight. The common arrangement of automotive disc brakes, has the bridge of the calliper (the section between the two sides) located around the outer perimeter of the disc, which may not be the optimum arrangement for a motor cycle.

DESCRIPTION

In this invention, the calliper (or callipers) are located around the inner (shorter radius) perimeter of the disc, and the disc is attached to the wheel with fasteners located adjacent to the outer perimeter.

For a given disc size, with the pad contact area remaining at the same radius, the body of the calliper can become smaller. The bridge section is much closer to the attachment of the calliper to the forks. This compact architecture will provide gains in terms of stiffness and the ratio of strength to weight.

Examples of the invention will now be described with reference to the accompanying drawings; In fig.1 there is shown the disc A with fastener locations B (six in this example) located on the outer perimeter. The Calliper C is shown with two holes D for fastening to the forks, with the crucial bridge section below the lower perimeter of the disc represented by E. In this invention, the disc and calliper are the components which are fundamentally different.

Fig..2 is a cross section of the disc A with the fastener locations B (two shown).

The bridge section E connects the two halves of the calliper C by folding around the inner perimeter of the disc.

In all drawings the mounting of the calliper/s to the fork is not shown in detail and could be by any known method. Likewise the fastening of the disc to the wheel could be any number and known type of fastener.

In fig.3 there is provided a disc A attached to the wheel G (shaded) by the fasteners B. The calliper C is attached to the fork F. In this example the calliper is shown with two pistons P and individual hydraulic supply lines H. The bridge section beneath and around the lower perimeter of the disc is shown as E. 3 represents the tyre.

In Fig.4 there is provided a calliper C with two pistons one each side of the fork F. In this example the body of the calliper becomes an integral part of the fork assembly. The bridge section E remains below the lower perimeter of the disc. The disc A is attached with fasteners B (five in this example) to the wheel G. In Fig.5 there is a similar arrangement to fig.3, except that the calliper C has been widened to reach the wider radial angles of the disc. Becoming effectively two callipers with common architecture, there are now two bridge sections E. Although the body of the calliper is less compact than the example in fig.4 it remains shorter and more rigid than a calliper with bridges around the outside perimeter of the same disc. In this example the disc A is provided with four fasteners B to the wheel G. Arrangements similar to figures 3, 4 & 5, with more than one piston, or more than one calliper, and when used with prior art wheel speed sensor, modulator and ECU, and with pistons and friction points located at different radial angles can be used to influence a range of forces. Tangential forces act directly on the wheel and tyre, and opposite reaction forces act upon the sprung mass, which in turn effect weight transfer under braking between front and rear wheels, as described in UK patent application 1309903.1.

With motor cycles it is common to have the rear brake controlled independently of the front by the rider. ABS may be provided on both wheels or front only. Shorter stopping distances can be achieved by making more use of the rear wheel, which requires resisting forward transfer of the sprung mass. Whether ABS is provided on the rear wheel or not, there is advantage in the application of a front calliper which is forward of the perpendicular and above the horizon. This friction point creates tangential downforce on the front wheel, and opposing (Newton's third law of motion) force up through the unsprung mass providing down force on the rear. This invention combined with previous application (1309903.1) provides this possibility, including the option to provide two callipers on the front wheel. In this arrangement, the rearward front calliper is applied initially. When a wheel speed sensor, front or rear, detects that the wheel is slowing too quickly, and just before the point of locking, engages the ECU and modulator to transfer the input pressure to the forward calliper.

Fig.6 shows the near-side view and the off-side view of the same wheel in a dual disc arrangement. The discs Al and A2 are of different diameters. The callipers are not shown in this instance.

When the wheel speed sensor detects that the wheel is about to lock, input pressure from the rider is transferred to the smaller disc. The smaller disc provides less friction and therefore less braking force for the same rider input.

Input pressure is then modulated back to the larger more efficient disc after a short period of time (SOth second for example). Modulation between callipers operating at different radii on the same disc for motor vehicles with more than two wheels, is described in UK patent application 1312062.1. Using separate discs of different diameter is an option better suited for motor cycles.

The range of options with this invention, and with reference to previous applications (1309903.1 & 1312062.1) include initial application on a large radius rearward front calliper, transferring to a forward calliper to assist downforce and rearward weight transfer, and, should it remain necessary to prevent locking the front wheel, transfer of input pressure to a calliper operating at a shorter radius, on the same disc or a separate disc of smaller diameter. There is constant braking pressure and no brake lever vibration experienced by the rider.

An addition benefit of placing the bridge of the calliper around the inner perimeter of the disc, is unrestricted air flow and heat dissipation from the outer perimeter. The fastening of the disc to the wheel, adjacent to the outer perimeter, may provide further opportunity, depending on materials used, to conduct heat into the wheel, with its large surface area.

Claims

CLAIMS1. An automotive disc brake with single or dual discs and multi calliper arrangements for motor cycles... where the disc is fastened adjacent to its outer perimeter, and the bridge of the calliper is located around the inner perimeter.
2. An automotive disc brake with single or dual discs and multi calliper arrangements for motor cycles... where various radial locations of callipers can be employed to influence weight transfer between front and back wheel under braking.Ref: Previous application 1309903.1.
3. An automotive disc brake with single or dual discs and multi calliper arrangements for motor cycles... where constant pressure anti-lock braking systems may be employed with callipers and friction points located at varying radial distances on one disc, or separate discs of different diameter.Ref: Previous application 1312062.1
4. An automotive disc brake with single or dual discs and multi calliper arrangements for motor cycles... providing new opportunities for heat displacement away from the disc.