WO2014091105A1

WO2014091105A1 - Bicycle braking system

Info

Publication number: WO2014091105A1
Application number: PCT/FR2013/052815
Authority: WO
Inventors: David Petitdemange; Ludovic BERTHET
Original assignee: Decathlon
Priority date: 2012-12-12
Filing date: 2013-11-21
Publication date: 2014-06-19
Also published as: FR2999144B1; FR2999144A1

Abstract

The invention concerns a braking system comprising two stirrups (2) each fitted with a sleeve (5) for assembly on a cleat (3), said sleeves being arranged to allow the stirrups (2) to move in axial rotation along a braking stroke defined between a spaced-apart position and a close position, each stirrup (2) being provided with a biasing spring (11) in the spaced-apart position, one of the stirrups (2) being provided with an assembly for adjusting the braking stroke thereof, which comprises a mobile member (14) mounted in axial rotation via a biasing device arranged to exert an immobilising force greater than the force exerted by the spring (11), and a fixed member (18), the members (14, 18) having, respectively, a finger (19) and two stops (20a, 20b), one stop (20b) defining the spaced-apart position, the other stop (20a) moving the mobile member (14) by exerting, on the stirrup (2), a force greater than the immobilising force, the force of the spring (11) equipping the stirrup (2) provided with the adjustment assembly being greater than the force of the spring (11) equipping the other stirrup (2).

Description

Bike braking system

The invention relates to a braking system for a bicycle and a bicycle equipped with such a braking system.

There are known braking systems called "V-brake", which comprise two brackets each equipped with a pad and a mounting sleeve on a bracket integral with the frame of the bike to be arranged on either side of a wheel with the pads facing respectively one side of the rim of said wheel.

In these systems, the stirrups are connected to a brake cable to be moved, under the effect of a traction exerted on said cable by the cyclist when he actuates a brake lever disposed on the handlebar, in axial rotation according to a braking stroke, and this from a position apart in which the pads are at a distance from the rim to a close braking position in which said pads are in contact with said rim.

Furthermore, at rest, the stirrups are constrained in the spaced apart position by at least one spring and the lever is held at rest by tensioning the cable by means of the spring, the actuation of said lever making it possible to exert a traction force which is greater than the return force of the spring to move the calipers to the close position of braking.

In order to be effective, these braking systems require a certain number of adjustments, in particular during their assembly on a bicycle at the factory or following the change of the wheel, or during the period of use of said bicycle, particularly with regard to wear skates.

In particular, to be able to ensure a correct functional clearance between the pads and the rims of the wheel, and thus effective braking, the balancing of the springs of such a system must be carefully adjusted. To do this, brake systems are known in which each caliper is equipped with a stress spring and comprises a screw for adjusting the tension of said spring, said screw being in particular disposed on the lower end of said stirrup. For example, US-5,788,020 discloses a stirrup of such a braking system.

However, this operation is particularly long and difficult to achieve, which can lead to assembly errors and therefore a refusal of the bike during a quality control performed at the factory.

Furthermore, the balance of the springs is sensitive to poorly controlled parameters, including the friction of the sleeves on the cleats, the routing and the deformation of the brake sheath, so that said balance is easily broken during the use of the bike and the balancing operation must be frequently repeated. In particular, when the balancing has not been correctly performed, one of the pads is permanently in contact with the rim of the wheel, which causes premature wear and generates an annoying noise. In addition, the adjustment screw is not very visible for the cyclist, and the balancing of the springs appears therefore not very intuitive.

To overcome these drawbacks, document EP-1 140 609 discloses a braking system in which each stirrup is provided with an adjustment assembly of its braking stroke comprising a friction element interposed between said stirrup and the amount of the bicycle to allow movement of said caliper relative to said amount.

However, this solution generates a tension problem in the brake cable, which results in the appearance of a game in said cable as and when the pads wear. To solve this problem, the document EP-1 140 609 provides for mounting a voltage adjusting device around the braking cable, this device being particularly complex. The invention aims to improve the prior art by proposing in particular a braking system which is arranged to present a balance of springs which is easily achievable during assembly and which is maintained in time automatically, in particular according to the skate wear. By Moreover, the invention proposes a braking system arranged to maintain a good tension of the braking cable without requiring the use of complex technical means. For this purpose, according to a first aspect, the invention provides a bicycle braking system comprising two brackets each equipped with a shoe and a mounting sleeve on a batten integral with the frame of the bicycle to be arranged on both sides. another of a wheel with the pads facing respectively one side of the rim of said wheel, said sleeves being arranged to allow the displacement in axial rotation of the stirrups on the batten in a braking stroke defined between a spaced apart position and a close position, each of said stirrups being equipped with a biasing spring of said stirrup in the spaced apart position, one of the stirrups being provided with an adjustment assembly of its braking stroke comprising a movable member mounted in axial rotation on the one of the sleeve and the cleat via a device for constraining said rotation, said device being arranged to exert a force of immobilization of the movable member which is greater than the force exerted by the spring equipping said stirrup, said assembly further comprising a fixed member intended to be secured to the other one of the cleat and the sleeve, a member having a finger and the other member forming two stops for defining a relative angular displacement stroke of said members, a first stop defining the spaced apart position of said stirrup when the finger is resting on it, the second stop serving to move the movable member by exerting on the stirrup a greater effort to the effort of immobilization of said movable member, the force of the spring equipping the stirrup provided with the adjustment assembly being greater than the force of the spring equipping the other stirrup.

According to a second aspect, the invention proposes a bicycle comprising a frame which has two uprights between which a wheel is mounted, each upright comprising a cleat on which is mounted the sleeve of respectively a stirrup of such a braking system, said bicycle. comprising a braking cable connected to the callipers for pulling said cable over a braking stroke from a remote position, wherein the skids are spaced from the rim, to a close position of braking, wherein said pads are in contact with said rim, each yoke being biased back into position by a spring, a first stop being arranged to define the position away from the caliper equipped with the adjustment assembly when the finger is resting on it, the second stop serving to move the movable member under the effect of a displacement of the stirrup with a force greater than the immobilization force said movable member exerted by the constraint device. Other features and advantages of the invention will appear in the description which follows, made with reference to the appended figures in which:

- Figure 1 shows in perspective partially exploded a stirrup provided with an adjustment assembly of a braking system according to one embodiment of the invention;

- Figures 2 show the stirrup of Figure 1 mounted on the batten, respectively in longitudinal section (Figure 2a) and in bottom view without the spring flange (Figure 2b);

- Figure 3 shows in perspective the stirrup of Figure 1 with the constraint device and the movable member in partial exploded view, Figure 3a showing in longitudinal section the caliper of Figure 3 in the assembled state;

- Figures 4 schematically show the adjustment steps of the stirrups of a braking system according to another embodiment of the invention during their mounting on either side of a bicycle wheel; - Figures 5 schematically show the adjustment of the braking stroke of the stirrups of Figures 4 during the use of the bicycle.

In connection with these figures, there is described below a braking system for a bicycle, and a bicycle equipped with such a braking system.

The bicycle comprises a frame which has two uprights between which a wheel 1 is mounted and the braking system comprises two brackets 2, each amount comprising a cleat 3 on which is mounted respectively a stirrup 2. For example, the braking system can be mounted on the amounts of a fork mounted at the front of the frame of the bike, with the stirrups 2 arranged on both sides. other of the front wheel, or on the rear stays of said frame, with the stirrups 2 arranged on either side of the rear wheel.

The stirrups 2 are each equipped with a pad 4 and a sleeve 5 for mounting on a cleat 3 to be arranged on either side of the wheel 1 with the pads 4 facing respectively one side of the rim of said wheel.

In relation with FIGS. 1 and 3, each stirrup 2 comprises a piece 6 for mounting a pad 4, said piece comprising a vertical slot 7 in which the base of said pad is mounted by means of a screw 8. vertical position of the pad 4 can be adjusted by loosening the screw 8 and sliding the base of said pad in the slot 7, before tightening the screw 8 once the desired position obtained. To change the pad 4, for example when it is worn, the cyclist loosens the screw 8 and removes the base of the slot 7.

In relation to FIG. 2a, each stirrup 2 comprises a lower end 2a equipped with a sleeve 5, said end being provided with a bore in which said sleeve is crimped. Furthermore, the sleeve 5 is disposed around the cleat 3 with the stirrup 2 disposed on the side of the distal end 3a of the cleat 3, said stirrup being fixed axially on said cleat by means of a clamping screw 9 mounted in said cleat, the screw 9 having a head 9a disposed in abutment on the outer face of said stirrup.

The sleeves 5 are arranged to allow the displacement in axial rotation of the stirrups 2 on respectively a cleat 3 according to a braking stroke defined between a spaced apart position (FIGS. 4c, 5c), in which the runners 4 are spaced from the rim of the wheel. 1, and a close position (Figures 4b, 5b), wherein said pads are in contact with said rim. To do this, in relation with FIG. 2a, the cleat 3 comprises a cavity formed on its outer periphery extending axially from the distal end 3a. said batten and over a portion of the length of said batten, the sleeve 5 being rotatably mounted around said print.

To enable the actuation of the braking system, the bicycle comprises a braking cable which is connected to the stirrups 2 during assembly of said system, each stirrup 2 comprising an upper end 2b equipped with a device 10 for connection to said cable. Thus, to actuate the braking system, the cyclist presses the brake lever disposed on its handlebar and corresponding to the wheel 1 that it wishes to immobilize, so as to exert traction on the cable and drive the stirrups 2 of said system to their close position of braking.

To recall the stirrups 2 in the separated position at the end of the braking, when the cyclist stops pressing the brake lever, each of said stirrups is equipped with a spring 1 1 stress of said stirrup in the spread position. In addition, the springs January 1 allow the return of the handle in the rest position and the tensioning of the brake cable.

In the embodiment shown, each spring 1 1 comprises a helical body 1 1 mounted around the sleeve 5. The helical body 1 1 a is extended by an upper rod 1 1 b held in position on a lug 12 of the caliper 2, as well as by an axial rod 1 1 c intended to be fixed to the cleat 3.

Each yoke 2 comprises a flange 13 in which the helical body 11a is disposed, said flange having a groove of which the axial rod 1 1c is projecting. In relation to FIG. 2b, the batten 3 comprises a proximal end provided with a flange 3b, said flange having an orifice in which the axial rod 11c is fixed. In particular, the axial dimension of the cleat 3 is greater than the axial length of the sleeve 5, the axial dimension of said sleeve being substantially equal to the axial dimension of the cavity in which it is arranged. Furthermore, the flange 13 is mounted around the part of the span of the cleat 3 which is not provided with the imprint, which avoids the rotational drive of said flange by the sleeve 5.

To avoid a tedious adjustment and without guarantee of efficiency of the balance of the springs January 1, one of the stirrups 2 is provided with a set of adjustment of its braking stroke.

In the embodiment shown in Figures 1 to 3, the adjustment assembly comprises a movable member 14 mounted in axial rotation on the sleeve 5 by means of a constraint of said rotation which is arranged to exert a force of immobilization of the movable member 14 greater than the force exerted by the spring 1 1 equipping the yoke 2. In particular, the constraint device comprises at least one friction element 15 interposed between the movable member 14 and the stirrup 2.

In particular, the movable member 14 comprises a washer disposed around the sleeve 5 and the friction element comprises two friction washers 15 disposed around the sleeve 5 and on either side of said movable member. In addition, the constraint device comprises a spring washer 16 and a clamping washer 17 mounted on the sleeve 5 and between which are arranged the movable member 14 and the friction washers 15, the spring washer 16 to ensure the pressure axial on said movable member and said friction washers 15 being held compressed by the clamping washer 17.

In addition, the adjustment assembly comprises a fixed member 18 intended to be secured to the cleat 3. To do this, the fixed member 18 comprises a radial lug 18a which has an assembly port to the cleat 3 via a screw mounted in said cleat. In particular, in the embodiment shown, the radial lug 18a of the fixed member 18 is interposed, during assembly of the yoke 2 on the cleat 3, between the head 9a of the mounting screw 9 and the outer face said stirrup, and this so as to be pressed against the distal end 3a of said cleat by means of said head. Thus, the movable member 14 and its constraint device are arranged around the sleeve 5 by being interposed between the fixed member 18 and the flange 13 of the spring 1 1, said flange further comprising at least one housing in which said members are partially arranged, in particular for aesthetic purposes.

Moreover, one of the members 14, 18 has a finger 19 and the other member 18, 14 forms two stops 20 to define a relative angular displacement stroke of said members. In FIGS. 1 to 3, the finger 19 extends radially from the washer of the movable member 14 and the fixed member 18 forms the stops 20. In particular, the fixed member 18 comprises two axial tabs 18b respectively defining a stop 20a, 20b, the finger 19 of the movable member 14 being disposed between said tabs. In the embodiment shown in Figures 4 and 5, the movable member 14 comprises a washer mounted in axial rotation on the cleat 3 and of which the finger 19 extends radially. In addition, the fixed member 18 is secured to the stirrup 2 to move in rotation with it relative to the cleat 3 and comprises an inner stop 20a intended to be disposed near the wheel 1 when said stirrup is mounted on a the amount of the bicycle, and an outer stop 20b to be disposed at a distance from said wheel.

Furthermore, the technical characteristics of the constraint device and the fixed member 18 described in relation with FIGS. 1 to 3 may be adapted to the assemblies of the movable member 14 and of said fixed member respectively on the cleat 3 and on the stirrup 2.

According to variants not shown, the movable member 14 may comprise the two stops 20a, 20b while being mounted in axial rotation on one of the sleeve 5 and the cleat 3, while the fixed member 18 may comprise the finger 19 while being secured to the other among the cleat 3 and the sleeve 5. The stops 20a, 20b are arranged so that a first stop defines the spaced apart position of the stirrup 2 provided with the adjustment assembly when the finger 19 bears on it. In relation to FIGS. 4 and 5, when the finger 19 is carried by the movable member 14 and mounted to rotate relative to the cleat 3, the inner stop 20a fulfills this function.

Thus, when the stirrup 2 provided with the adjustment assembly is returned to its separated position by the spring 1 1 with which it is equipped, the restoring stroke of said stirrup is interrupted when the finger 19 of the movable member 14 enters into position. contact with the inner stop 20a.

Moreover, once the finger 19 is in contact with the outer abutment 20a, the immobilization force exerted by the constraint device on the movable member 14 prevents any additional movement towards the outside of said movable member, and therefore of the stirrup 2, so that the pad 4 equipping said stirrup will deviate from the rim only by the distance corresponding to the spaced apart position, and the pad 4 fitted to the other stirrup 2 will not approach the rim at beyond this distance. In addition, the force of the spring 1 1 equipping the yoke 2 provided with the adjustment assembly is greater than the force of the spring 1 1 equipping the other yoke 2, so that the position spaced from the two calipers 2 is obtained only by pressing on the inner stop 20a, and it is not necessary to manually balance the springs 1 January. In addition, the force of the spring 1 1 equipping the other arm 2 constantly stretches the brake cable without requiring manual adjustment of said voltage.

So that the distance in position spaced between each pad 4 and the side of the rim opposite which it is arranged is always optimal, an adjustment is necessary, especially when mounting the braking system on the bike, either as a result of assembly at the factory or the replacement of the wheel 1, or as and when the wear of the pads 4. For example, this distance can be of the order of 1 mm. To do this, the second stop of the adjustment assembly serves to move the movable member 14 relative to the sleeve 5 by exerting on the stirrup 2 a force greater than the immobilization force exerted on said movable member by the constraint device, for example by moving said stirrup manually (when mounting the brake system on the bike) or by means of the brake lever (when using the bicycle). In relation to FIGS. 4 and 5, when the finger 19 is carried by the movable member 14 and mounted to rotate relative to the cleat 3, the outer stop 20a fulfills this function.

As shown in FIGS. 4, during assembly of the stirrups 2 on the uprights of the bicycle, the braking stroke of said stirrups has not yet been adjusted (FIG. 4a). By manually bringing the stirrups 2 of the wheel 1 until the pads 4 come into contact with the rim, a greater force is exerted on the immobilizing force, which causes the displacement of the movable member 14 by pressing the finger 19 on the outer abutment 20b secured to the yoke 2 (Figure 4b).

By releasing the force exerted on the stirrups 2, each of said stirrups is biased into the spaced position by a spring January 1, and until the finger 19 comes into contact with the inner stopper 20a, the immobilization force the constraint device then preventing any further movement of the stirrups 2 outwards (Figure 4c). Similarly, as the pads 4 wear out, the distance between each of said pads and the rim increases. As shown in FIGS. 5, to adjust the braking stroke to this wear, the cyclist exerts a displacement force on the stirrups 2 by pressing on the brake lever until the finger 19 comes into contact with the stop 20b external adjustment (Figures 5a, 5b). The induced displacement force being greater than the immobilization force exerted by the stress device, the support of the finger 19 on the second stop causes the displacement of the movable member 14 until the pads 4 come into contact with the rim (Figure 5b). Thus, by releasing the brake lever, the cyclist allows the stirrups 2 to be returned to the remote position by pressing the finger 19 on the inner stop 20a, said inner stop having been moved to adjust to the wear of the pads 4 (Figure 5c) and thus do not lose the adjustment of the distance position spaced between said pads and the rim.

In addition, the angular difference between the abutments 20a, 20b is substantially equal to the braking stroke of the yoke 2 provided with the adjustment assembly. In particular, the system ensures that the pads 4 are never in contact with the rim at rest.

Thus, the braking system according to the invention makes it possible to save time during assembly of the bicycle, especially at the factory or while reassembling a wheel, while reducing the maintenance and adjustment operations to be carried out for the cyclist as and when using the bicycle.

Claims

1. Bicycle brake system comprising two stirrups (2) each equipped with a pad (4) and a sleeve (5) for mounting on a cleat (3) integral with the frame of the bicycle to be arranged on both sides a wheel (1) with the pads (4) opposite respectively one side of the rim of said wheel, said sleeves being arranged to allow axial displacement of the stirrups (2) on the cleat (3) following a braking stroke defined between a spaced apart position and a close position, each of said stirrups being equipped with a spring (1 1) of stress of said stirrup in the spaced apart position, said system being characterized in that one of the stirrups (2) is provided with an adjusting assembly of its braking stroke comprising a movable member (14) mounted in axial rotation on one of the sleeve (5) and the cleat (3) via a constraining device of said rotation, said device being arranged to exert an effo immobilizing the movable member (14) which is greater than the force exerted by the spring (1 1) equipping said yoke, said assembly further comprising a fixed member (18) intended to be secured to the other among the cleat (3) and the sleeve (5), a member (14, 18) having a finger (19) and the other member (18, 14) forming two stops (20a, 20b) for defining a displacement stroke relative angle of said members, a first stop (20b) defining the spaced apart position of said stirrup when the finger (18) bears on it, the second stop (20a) serving to move the movable member (14) by exerting on the stirrup (2) a force greater than the immobilizing force of said movable member, the force of the spring (1 1) equipping the stirrup (2) provided with the adjustment assembly being greater than the spring force (1 1) equipping the other stirrup (2).

2. Braking system according to claim 1, characterized in that the angular spacing between the stops (20a, 20b) is substantially equal to the braking stroke of the stirrup (2) provided with the adjustment assembly.

3. Braking system according to claim 1 or 2, characterized in that the movable member (14) is mounted in axial rotation on the sleeve (5), the fixed member (18) being intended to be secured to the cleat ( 3).

4. Braking system according to any one of claims 1 to 3, characterized in that the movable member (14) comprises a washer, the finger (19) extending radially from said washer.

5. Braking system according to any one of claims 1 to 4, characterized in that the constraint device comprises at least one friction element (15) interposed between the movable member (14) and one of the stirrup (2) and the cleat (3).

6. Braking system according to claim 5, characterized in that the friction element comprises two friction washers (15) disposed on either side of the movable member (14).

7. Braking system according to claim 5 or 6, characterized in that the constraint device comprises a spring washer (16) and a clamping washer (17) between which are arranged the movable member (14) and the element friction (15).

8. Braking system according to any one of claims 1 to 7, characterized in that the fixed member (18) comprises two axial lugs (18b) respectively defining a stop (20a, 20b), the finger (19) of the movable member (14) being disposed between said tabs.

9. Braking system according to any one of claims 1 to 8, characterized in that the fixed member (18) comprises a radial tab (18a) which has a means of association with one of the stirrup ( 2) and the cleat (3).

10. Braking system according to any one of claims 1 to 9, characterized in that each spring (1 1) comprises a helical body (1 1 a) mounted around the sleeve (5), said body being extended by a rod upper (1 1 b) held in position on a lug (12) of the stirrup (2), said body being further extended by an axial rod (1 1 c) intended to be fixed to the cleat (8).

1 1. Bicycle comprising a frame which has two uprights between which a wheel (1) is mounted, each upright comprising a cleat (3) on which is mounted the sleeve (5) of respectively a stirrup (2) of a braking system according to l any one of claims 1 to 10, said bicycle comprising a braking cable connected to the brackets (2) for pulling said cable on a braking stroke from a remote position, wherein the pads (4) are separated from the rim, to a close braking position, wherein said pads are in contact with said rim, each yoke (2) being biased back into position by a spring (1 1), a first stop (20a) being arranged to define the position away from the stirrup (2) provided with the adjustment assembly when the finger (19) bears on it, the second stop (20b) serving to move the movable member (19) under the effect of a displacement of the stirrup (2) with u n force greater than the immobilizing force of said movable member exerted by the constraint device.

12. A bicycle according to claim 14, characterized in that the sleeve (5) of each stirrup (2) is arranged around the cleat (3) with said stirrup disposed on the side of the distal end (8a) of said cleat, said stirrup being fixed to said cleat by means of a screw (9) clamping mounted in said cleat, the screw (9) comprising a head (9a) disposed in abutment on an outer face of the stirrup (2), the fixed member (18) being interposed between said head and said outer face to be secured to the cleat (3).

13. Bicycle according to claim 12, characterized in that the axial dimension of the cleat (3) is greater than the axial dimension of the sleeve (5), the fixed member (18) being pressed axially against the cleat (3) by means the head (9a) of the tightening screw (9).