CONTROL DEVICE FOR HYDRAULIC BRAKES OF A TWO-WHEELED VEHICLE

Abstract

A control device comprises two brake master cylinders (13, 14), both of which may be operated simultaneously by the same single manual control lever (15), according to a combined or integral braking mode. A switching element (27), associated with the manual control lever (15), may exclude one (14) of the two brake master cylinders.

Claims

1. A control device (10) for the hydraulic brakes of a two-wheeled vehicle provided with a first brake for a first wheel and a second brake for a second wheel, the control device comprising: a first brake master cylinder (13) comprising: a master cylinder body (11), a first hydraulic chamber (16) formed in the master cylinder body (11) and hydraulically connectable to the first brake, and a first piston (17), movable in the first hydraulic chamber (16); a single manual control lever (15), rotatable with respect to the master cylinder body (11), acting on the first piston (17) to operate the first brake; characterized in that the control device (10) further comprises: a second brake master cylinder (14), comprising: a second hydraulic chamber (21) formed in the master cylinder body (11) and hydraulically connectable to the second brake, and a second piston (22), movable in the second hydraulic chamber (21) for operating the second brake by means of said manual control lever (15), a switch element (27), associated with the manual control lever (15), to selectively activate and deactivate the second piston (22), the switch element (27) having two alternative positions: a first passive position, in which a rotation of the manual control lever (15) does not activate the second piston (22), and a second active position, in which a rotation of the manual control lever (15) simultaneously actuates the first piston (17) to actuate the first brake and the second piston (22) to actuate the second brake, according to a combined or integral braking mode.

2. A control device according to claim 1, wherein the switching element (27) is a cam device comprising an eccentric surface (30).

3. A control device according to claim 1 or 2, wherein the switching element (27) is rotatably mounted on the manual control lever (15).

4. A control device according to claim 1 or 2 or 3, wherein the manual control lever (15) is pivotally mounted to the master cylinder body (11).

5. A control device according to any one of the preceding claims, wherein the two hydraulic chambers (16, 21) are adjacent, parallel and arranged one above the other.

6. A control device according to any one of the preceding claims, wherein the manual control lever (15) acts in thrust relationship on the second piston (22) by means of a second intermediate thrust or transmission member (23), rotatably mounted to the master cylinder body (11) about a rotation axis (25) coincident or parallel to a hinging axis of the manual control lever (15) to the master cylinder body (11).

7. A control device according to claim 6, wherein the second intermediate transmission member (23) is made as a lever, particularly a second-class lever, having a thrust portion (24) acting against the second piston (21) and an engagement surface (26) on which the switching member (27) may optionally operate.

8. A control device according to any one of the preceding claims as dependent on claim 2, wherein the switching element (27) includes a pin (28), which can be rotated by means of a wheel (29) accessible to the driver, and said eccentric surface (30), which is eccentric with respect to the pin (28).

9. A control device according to any one of the preceding claims, wherein the master cylinder body (11) forms a top reservoir (31) to supply the brake fluid to the first hydraulic chamber (16).

10. A control device according to any one of the preceding claims, wherein the manual control lever (15) acts in a thrust relationship on the first piston (17) by means of a first intermediate transmission or thrust member (18) rotatably mounted to the master cylinder body (11) about a rotation axis coincident or parallel to a hinging axis about which the manual control lever (15) is pivotally mounted to the master cylinder body (11).

11. A control device according to any one of the preceding claims, wherein the first intermediate transmission member (18) is adjustable with respect to the control lever (15) by means of an adjustment element (19) which allows the rest position of the manual control lever (15) to be adjusted, placing it closer to or farther from a vehicle handlebar.

12. A control device according to claim 11, wherein an elastic element (20) is interposed and acting in a thrust relationship between the first intermediate thrust member (18) and the manual control lever (15), for urging the first intermediate member (18) constantly towards the adjustment element (19) to take up the play between the intermediate thrust member (18) and the manual control lever (15).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Some preferred but non-limiting embodiments of a brake control device according to the invention will now be described, with reference to the accompanying drawings, wherein:

[0008] FIG. 1 is a sectional view from above of a brake control device;

[0009] FIG. 2 is a sectional view from below, according to a lower section plane than that of FIG. 1, showing the brake control device in a first non-activated position;

[0010] FIG. 3 is a sectional view similar to FIG. 2, illustrating the brake control device in a second activated position;

[0011] FIG. 4 is an exploded view of the control device of FIG. 1-3;

[0012] FIG. 5 is a top view of the brake control device of FIG. 1;

[0013] FIG. 6 is a vertical sectional view of the brake control device;

[0014] FIG. 7 is another exploded perspective view of some of the components of the brake control device; and

[0015] FIG. 8 illustrates the control device in a condition in which a switching element is in the inactive position.

DETAILED DESCRIPTION

[0016] With reference to the figures, numeral 10 indicates in its entirety a control device for the hydraulic brakes of a two-wheeled vehicle (not shown), equipped with a first rear brake for a rear wheel and a second front brake for a front wheel.

[0017] The control device 10 comprises a master cylinder body 11 which may be attached to a handlebar (not shown) of the two-wheeled vehicle. For attaching to the handlebar, the master cylinder body 11 may have a cylindrical seat 12. The control device 10 comprises a first 13 and a second 14 brake master cylinder, both of which may be operated by the same single manual control lever 15.

[0018] The master cylinder body 11 may be made of plastics or metal material.

[0019] The control lever 15 is hinged to the master cylinder body 11 about a hinging axis which, in conditions of use, is oriented substantially vertically or slightly inclined.

[0020] To optimize the overall dimensions, the first brake master cylinder 13 is preferably located adjacent to the second brake master cylinder 14. According to a preferred embodiment, the first brake master cylinder is located immediately above the second brake master cylinder.

[0021] The first brake master cylinder 13 comprises a first hydraulic chamber 16 formed in the master cylinder body 11 and hydraulically connectable to the rear brake, and a first piston 17, movable in the first hydraulic chamber 16.

[0022] Advantageously, the master cylinder body 11 also forms a top reservoir 31 to supply brake fluid (for example oil) to the first hydraulic chamber 16 and thus to the first brake, the rear one in this example. The second hydraulic chamber 21 may be fed by the hydraulic circuit (not shown) of the second brake, the front one in this example. A lid for closing the tank 31 is indicated with 32.

[0023] According to an embodiment, the control lever 15 may act in a thrust relationship on the first piston 17 by means of a first intermediate transmission or thrust member 18, rotatably mounted on the master cylinder body 11 about a rotation axis coincident or parallel to the hinging axis of the lever 15 to the master cylinder body 11.

[0024] Preferably, the first intermediate transmission member 18 is adjustable with respect to the control lever 15, for example by means of an adjustment screw 19. The adjustment screw 19 allows the rest position of the control lever 15 to be adjusted, placing it nearer or further away from the handlebar according to the size of the user's hand.

[0025] According to an embodiment, an elastic element 20, for example a compression spring, interposed and acting in thrust relationship between the first intermediate thrust member 18 and the control lever 15, may be provided to urge the first intermediate member 18 constantly against the adjustment screw and to take up the play between the member 18 and the lever 15, preventing the transmission of vibrations. The intermediate thrust element 18 may be made of a first material, for example forged aluminum, while the control lever 15 may be made of a second lighter material, for example an aluminum alloy.

[0026] The lever 15, when rotated in the direction indicated by the arrow A (FIG. 1), acts on the first piston 17 of the first brake master cylinder 13 to operate the rear brake. Optionally, by operating a switching member 27, the driver may actuate simultaneously the front brake as well as the rear brake with the same actuating movement of the control lever 15.

[0027] The second brake master cylinder 14 comprises a second hydraulic chamber 21, formed in the master cylinder body 11 and hydraulically connectable to the front brake, and a second piston 22, movable in the second hydraulic chamber 21.

[0028] According to a preferential and particularly compact embodiment, the two hydraulic chambers are adjacent, parallel and arranged one immediately above the other.

[0029] According to an embodiment, the control lever 15 may act in thrust relationship on the second piston 22 by means of a second intermediate thrust or transmission member 23, rotatably mounted to the master cylinder body 11 about a rotation axis 25 coincident or parallel to the hinging axis of the lever 15 to the master cylinder body 11.

[0030] According to a preferential embodiment, the second intermediate transmission member is obtained as a lever, in particular a second-class lever, having a thrust portion 24, acting against the second piston 21 and an engagement surface 26 on which the switching member 27 may optionally act.

[0031] The switching member 27 may be rotatably mounted to the manual control lever 15. The switching member 27 may advantageously be obtained as a cam switching member. In the illustrated preferred embodiment, the switching member 27 includes a pin 28, which may be rotationally actuated by means of a wheel 29 accessible to the driver, and a surface 30 which is eccentric with respect to the pin 28. By acting on the wheel 29, the driver may vary the angular position ofthe eccentric surface 30 between a passive position and an active position.

[0032] When the driver wishes to operate the front and rear brakes simultaneously by means of the manual control lever 15, the wheel 29 must be rotated so that the eccentric surface 30 moves to the position illustrated in FIG. 2, where the eccentric surface 30 is in contact with the second transmission member 23. By rotating the manual control lever 15, the eccentric surface 30 stresses the second intermediate transmission member 28 which thrusts the second piston 22 (FIG. 3), actuating the front brake. The actuation of the manual control lever 15, in this first operating mode, produces the simultaneous activation of the front and rear brakes of the two-wheeled vehicle, according to a combined or integral braking mode.

[0033] Alternatively, when the driver wishes to exclude the front brake from the influence of the manual control lever 15, the wheel 29 must be turned so that the eccentric surface 30 moves to an inactive position (FIG. 8), where the eccentric surface 30 is spaced apart and does not interfere with the second transmission member 23 when the manual control lever 15 is operated.

[0034] Various aspects and embodiments of the brake control device have been described; it is understood that each embodiment may be combined with any other embodiment. Furthermore, the embodiments and the constructional details may be widely varied with respect to that which has been described and illustrated purely by way of non-limiting example, without thereby departing from the scope of the invention, as defined in the appended claims.