GB1578668A

GB1578668A - Braking system for a bicycle

Info

Publication number: GB1578668A
Application number: GB705277A
Authority: GB
Original assignee: SUELE S
Current assignee: SUELE S
Priority date: 1976-02-21
Filing date: 1977-02-18
Publication date: 1980-11-05
Also published as: FR2341463A1; FR2341463B3; IT1085863B; NL7701826A; ATA109077A; JPS52101377A; AT373839B

Description

(54) A BRAKING SYSTEM FOR A BICYCLE (71) I, SANDOR SIDLE, of Swiss nationality, of CH-8200 Schaffhausen, Steigstrasse 77, Switzerland, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to a braking system on a bicycle.

Conventional hydraulic brake systems, as used in motor vehicles, are unsuitable for bicycles because of their cost and because of their complicated construction.

According to the present invention there is provided a braking system on a bicycle, the braking system comprising a brake handle, which is movable to compress a master bellows, and a brake pad which is drivable, by expansion of a slave bellows, into frictional engagement with a braking surface which is rotatable with a wheel of the bicycle, the interior of the master bellows communicating with the interior of the slave bellows, whereby compression of the master bellows by the handle causes the brake pad to be applied to the braking surface by the slave bellows, each bellows comprising an outer variable-volume casing and an inner variable-volume lining which is impervious to liquid.

With a system in accordance with the present invention, it is possible to control precisely the deceleration of the bicycle, and no brake fluid can escape from the closed system.

The bellows may be made from material in the form of interconnected circular sections which can collapse against one another in the manner of a concertina.

Within the master bellows there may be a resilient return means, the resilience of which can be adjusted to suit prevailing conditions.

A braking system in accordance with the present invention can be produced at low cost and is readily maintained. It can be used with bicycles with or without an auxiliary engine.

For a better understanding of the present invention and to show how it may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings, in which: Figure 1 is a diagrammatic representation of a bicycle braking system having a drum brake; Figure 2 shows a disc brake mechanism; Figure 3 is a perspective view of the mechanism of Figure 2; Figure 4 is a diagrammatic plan view of a bicycle braking system; Figure 5 is a partially sectioned side view of a bicycle braking system; and Figure 6 is a detail of Figure 5 taken along the line VIII in Figure 5.

In the braking system of Figure 1, a brake handle 1 is connected to a master bellows 2, which is connected by pipework 3 with a slave bellows 4 on a bicycle wheel.

The master bellows 2 is connected to the handle 1 by a bolt 7 which is coaxial with the bellows. The volume of the master bellows 2 is reduced when the handle 1 is pivoted about its fulcrum 8 in the direction of the arrow X. The master bellows 2 and the slave bellows 4 each comprise a variable-volume casing constructed in the manner of a metallic water hose, having circular sections 10 which are interconnected by flexible parts 11.

The interior J of the bellows 2 is provided with resilient return means in the form of a coil spring 12 which urges the bellows 2 into an inoperative position of maximum volume. A variable-volume lining comprising liquid-impervious protective foil 13 is situated between the coil spring 12 and the material of the casing.

If the bellows 2 is compressed against an abutment W by operation of the handle 1, the fluid in the pipework 3 and in the bellows 2, 4 is pressurised and the slave bellows 4 is extended to pivot a brake shoe 14, which is pivoted to a non-rotating part of a wheel hub 5 at 14s, to press a brake pad or lining 15 against a braking surface of a brake drum 16. After the braking operation the brake shoe 14 and the slave bellows 4 are returned into their initial position by a tension spring 17.

When the handle I is actuated, the slave bellows 4 in Figures 2 and 3 act in a similar manner to that of Figure 1 to press brake pads against a brake disc 18 which rotates with the wheel. The slave bellows 4 are situated one on each side of the brake disc 18 in bellows housings 19 of calipers 20 which are secured on a non-rotating stub axle of the vehicle (not shown).

Figure 4 shows two brake shoes 114 with brake pads or blocks 115 of rubber or the like situated one on each side adjacent to the rim of a bicycle wheel E, controlled by handlebars G and a steering fork H. Each of the brake shoes 114 is biassed towards an inoperative position by return springs 31 which are placed around bolts 30. The return springs 31 are supported in a retaining block 32 which has a lateral support arm 34 clamped to a lateral lug 35 of the steering fork H. A slave bellows 40 disposed between the bolts 30 acts against the outer-face 36 of the brake shoe 114. As shown in Figure 4, the slave bellows 40 is situated in a block 104S and communicates through pipework 3f with a T-connector 6 which is connected by a common hose 3 with the master bellows 104 mounted in a brake casing 41 on the handlebar G.

In Figure 4, the master bellows 104 can be compressed by a bolt 107 by means of a brake handle 42 which is pivotably mounted on the handlebar G.

Similarly, in the embodiment of Figures 5 and 6, pulling of the brake handle 42 towards the handlebar G in the arrow direction T, causes an adjustment screw 46 which is loaded by a spring 47, to press against a bolt 107 of the master bellows 102.

The volume of the bellows 102 is reduced and brake fluid B situated in the hydraulic system 102-3-104 is pressurised to expand the slave bellows 104. The latter press the brake shoes 114 and the brake blocks 115 uniformly against the wheel rim and cause effective-but smooth-stopping of the bicycle.

WHAT I CLAIM IS: 1. A braking system on a bicycle, the braking system comprising a brake handle, which is movable to compress a master bellows, and a brake pad which is drivable, by expansion of a slave bellows, into frictional engagement with a braking surface which is rotatable with a wheel of the bicycle, the interior of the master bellows communicating with the interior of the slave bellows, whereby compression of the master bellows by the handle causes the brake pad to be applied to the braking surface by the slave bellows, each bellows comprising an outer variable-volume casing and an inner variable-volume lining which is impervious to liquid.

3. A braking system as claimed in claim 1 or claim 2, in which resilient return means is provided in the master bellows for urging that bellows to its maximum volume state.

4. A braking system as claimed in claim 3, in which the resilient return means is adjustable.

5. A braking system as claimed in any one of the preceding claims in which the bellows each comprise material formed as a plurality of interconnected circular sections which are collapsible one another in the manner of a concertina.

6. A braking system as claimed in any one of the preceding claims, in which one end of the master bellows engages an abutment and the other end is provided with a bolt which is engaged by the handle in operation.

7. A braking system as claimed in any one of the preceding claims, in which the brake pad is one of two oppositely-acting brake pads disposed for frictional engagement with opposite sides of a wheel rim, each brake pad having a respective slave bellows.

8. A braking system substantially as described herein with reference to the accompanying drawings.

9. A bicycle having a braking system in accordance with any one of the preceding

Claims

claims.