Hydraulic brake control unit and handlebar assembly

Abstract

A hydraulic brake control unit for a handlebar steered vehicle includes a cartridge (12) mounted within a handlebar tube (10) of the vehicle and defining a longitudinally extending cavity (13) therein having a port (16) at one end thereof, a piston (14) housed within the longitudinally extending cavity (13), and a transfer lever (17) pivotally mounted on the handlebar tube (10). The transfer lever (17) exerts a pushing force in a first longitudinal direction toward the port (16) between a brake application lever (11) and the piston (14). A flow passage (18) formed within the cartridge (12) fluidly connects the port (16) of the longitudinal cavity (13) with a hydraulic hose (20) to define a U-shaped path for the brake fluid and to exert a pressure on the brake fluid contained within the hydraulic hose in a second longitudinal direction opposite the first longitudinal direction.

Description

[Technical field]

[0001] The present invention relates to the field of handlebar-steered vehicles with hydraulic brakes. The present invention relates to an integrated control unit for hydraulic brakes of vehicles operated with handlebar steering. More particularly, but not exclusively, the control unit of the present invention is applicable to bicycles. [Background technology]

[0002] As is well known, many bicycles and other handlebar-operated vehicles are equipped with hydraulic braking systems in which a brake master cylinder is actuated by a brake control lever on the handlebar and controls a brake caliper associated with each wheel via hydraulic hoses. The master cylinder and associated tank containing a reservoir of brake fluid are mounted on the handlebar near the brake lever. The hoses extend externally along the handlebar.

[0003] US2019 / 0152457A1 discloses a control unit for hydraulic brakes or clutches on a vehicle operated by handlebar steering. A brake master cylinder is disposed inside the handlebar tube, and a hydraulic hose is hydraulically connected to the master cylinder and extends internally within the handlebar tube. A manual operating lever external to the handlebar is pivotally coupled to a piston in the master cylinder via a tie rod drive element that exerts a pulling force on the piston when the operating lever is actuated. DISCLOSURE OF THEINVENTION

[0004] The present invention provides a master cylinder control unit that is integrated into the handlebar tube of a vehicle with a hydraulic braking system, with the brake fluid hose passing through the handlebar tube.

[0005] The object of the present invention is to provide a control unit which is compact, reliable in operation, easy to install in the handlebar tube and preferably offers the possibility to adjust the braking load curve in the different braking stages according to requirements.

[0006] According to the present invention, the above and other objects and advantages are achieved by a hydraulic brake control unit having the features recited in the appended claims.

[0007] In summary, the hydraulic brake control unit includes a cartridge configured to be mounted inside a handlebar tube. The cartridge defines an interior longitudinally extending cavity having a port at one end thereof. A longitudinally movable piston is partially housed within the longitudinally extending cavity. A transfer lever pivotally mounted to the handlebar tube about a transverse axis acts between the brake operating lever and the piston to apply a first longitudinal thrust to the piston toward the port. A passage is formed within the cartridge defining a U-shaped path for brake fluid, the passage fluidly coupling the port of the longitudinally extending cavity to a hydraulic hose also housed within the handlebar tube.

[0008] Preferred embodiments are set forth in the dependent claims. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view of a hydraulic brake control assembly integrated into the handlebar tube of a handlebar steered vehicle with a manual brake lever. [Diagram 2] FIG. 2 is a cross-sectional view similar to FIG. 1, but taken at a different cross-sectional angle. [Diagram 3] FIG. 3 is another cross-sectional view similar to FIGS. 1 and 2, but taken at a different cross-sectional angle. [Figure 4] FIG. 4 is an enlarged cross-sectional view showing a detail of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Some preferred but non-limiting embodiments of the hydraulic brake control unit according to the present invention will now be described.

[0011] With reference to the drawings, a control unit for hydraulic brakes of a handlebar steered vehicle, particularly (but not limited to) a bicycle, is integrated into a handlebar tube 10, more particularly into the straight end region of the handlebar tube 10.

[0012] The handlebar tube 10 defines a central axis x, referred to herein as "longitudinal." Throughout this specification and the appended claims, directional and orientation terms such as "longitudinal," "lateral," "outer," and "inner" are to be construed with reference to the longitudinal axis x, unless otherwise indicated.

[0013] A brake application lever 11 is mounted on the handlebar tube 10 so as to be rotatable about an axis 11a transverse to the longitudinal axis x.

[0014] A cartridge 12 is inserted into and tightly fits within the handlebar tube 10, forming a longitudinally extending cavity 13 therein with a port 16 located at one end of the cavity 13 (FIG. 2) and facing, in use, towards the end 10a of the handlebar tube (to the right in FIGS. 1-3). The port 16 provides a passage for brake fluid used to operate the hydraulic brakes.

[0015] A piston 14 is partially housed in a longitudinally extending cavity 13 so as to be longitudinally movable. The piston 14 can be actuated by the brake lever 11 via a transmission mechanism 15 comprising a transmission lever 17 mounted on the handlebar tube 10 so as to be rotatable about a transverse axis 17a.

[0016] According to one embodiment, the transmission lever 17 is made as a rocker arm and has an arm 17 c which passes through the handlebar tube 10 through the opening 10 c and engages against one end of the piston 14 remote from the port 16 .

[0017] The transmission lever 17 can be operated by the brake lever 11 to exert a longitudinal thrust on the piston, thereby advancing the piston in a first or longitudinal direction within the longitudinal cavity 13 towards the port 16.

[0018] A compression spring 19 is interposed within the longitudinal cavity 13 between the piston 14 and the bottom of the longitudinal cavity 13 on the port 16 side. The spring 19 biases the piston 14 away from the port 16.

[0019] Within cartridge 12 is a passage 18 forming a U-shaped pathway for brake fluid, the passage 18 extending from port 16 to a hydraulic hose 20 which is contained within handlebar tube 10 and extends in a second longitudinal direction or direction opposite to the first actuation direction of piston 14 for transmitting pressure exerted by piston 14 when brake operating lever 11 is operated to a hydraulic caliper (not shown).

[0020] For structural reasons, the cartridge 12 may be made of multiple joined parts. The cartridge 12 may be made of a plastic material or a metallic material such as aluminum or its alloys.

[0021] According to one embodiment, the transmission mechanism 15 may also comprise an intermediate lever 22 rotatably mounted on the braking lever 11 about a lateral axis of rotation 22a.

[0022] According to the particular embodiment illustrated herein, the intermediate lever 22 is pivotally mounted on the handlebar tube 10 about a lateral axis of rotation 22a which coincides with the lateral axis 11a on which the brake application lever 11 is pivotally mounted.

[0023] A wheel 21 which is free to rotate about a lateral axis of rotation is attached in this embodiment to an intermediate lever 22 .

[0024] When the brake lever 11 is actuated and pulled towards the handlebar tube 10 , the wheel 21 acts in a thrust relationship by rolling against and along the surface 23 of the transfer lever 17 .

[0025] The intermediate lever 22, together with the brake control lever 11, is biased by a spring 24 which tends to move the brake control lever 11 towards the handlebar tube 10, and at the same time the intermediate lever 22 is biased against an adjustment screw 25 attached to the brake control lever 11.

[0026] An optional adjustment screw 25 serves to adjust the rest position of the brake operating lever 11 depending on the size of the user's hand, and in particular the length of the user's fingers. When the brake operating lever 11 is pulled towards the handlebar tube 10, the intermediate lever 22 is biased by the adjustment screw 25 to rotate clockwise about the axis 22a.

[0027] In other embodiments (not shown), the wheel 21 may be rotatably mounted directly on the brake arrest lever 11. In such an embodiment, the intermediate lever 22 and the adjusting screw 25 are not present.

[0028] According to a preferred embodiment, a stop element 26 (Figures 1 and 3) is fixed on the handlebar tube 10 in a stable position relative to the cartridge 12 and cooperates with a projection 17b of the transmission lever 17 to define, in the rest or inoperative position of the brake (Figures 1 and 3), an end-of-stroke position of the piston 14 at the opposite end to the end providing the brake fluid port 16. In the end-of-stroke position (shown in Figures 1 and 3), the thrust exerted by the spring 19 on the piston 14 is released on the transmission lever 17, whose rotation is prevented by the stop element 26.

[0029] The cartridge 12 is inserted into the handlebar tube 10 through the open end (right side) of the handlebar tube until the piston 14 abuts against the arm 17c of the transmission lever 17 and reaches a stop position defined by the protrusion 17a abutting against the stop element 26.

[0030] According to a preferred embodiment, the cartridge 12 further defines a reservoir 27 (FIGS. 1 and 3) for brake fluid, which is also housed within the handlebar tube 10 and is in fluid communication with the longitudinally extending cavity 13 via a passage bore 28 (FIG. 1).

[0031] In a known manner, one or more annular gaskets 29 are attached to the piston 14, the longitudinal position of which, relative to the passage bore 28, defines the so-called "dead stroke", i.e. the length of initial extension covered by the piston, during which the movement of the piston does not cause the outflow of brake fluid from the longitudinally extending cavity 13 through the port 16.

[0032] Preferably, the fluid passage 18 within the cartridge 12 is connected to a hose 20 by a high pressure connector 30 (FIG. 2).

[0033] According to one embodiment, a longitudinal adjustment screw 31 acting on one end of the cartridge 12 is provided for adjusting the relative longitudinal position of the cartridge with respect to the piston 14. By adjusting the relative rest position between the seal 29 of the piston 14 and the passage bore 28 of the cartridge 12, the length of the piston "dead stroke" is adjusted accordingly.

[0034] In the illustrated embodiment, the adjustment screw 31 engages through a central threaded hole 32 provided in a rigid disc plug 33 , preferably made of metal, which may be secured within the handlebar tube 10 .

[0035] According to one embodiment, the longitudinal position of the rigid disc plug 33 in the handlebar tube 10 is determined by a shoulder provided by a locking element 35 inserted into the handlebar tube 10 and preferably made of a plastic material.

[0036] The locking element 35 may include peripheral teeth 36 that may be fitted and engaged into respective through openings 37 formed through the handlebar tube 10. The locking element 35 serves as a shoulder for the rigid disc plug 33 and has a central bore 38 therethrough that is adapted to receive the adjustment screw 31.

[0037] Preferably, the central hole 38 is at least partially aligned in cross section with the peripheral locking teeth 36. This arrangement prevents unwanted disengagement of the peripheral teeth 36 from the opening 37 in the handlebar tube 10 due to the central presence of the central adjustment screw 31 in the locking element 35. The brake application lever 11 is attached to the handlebar tube 10 in this example by means of two complementary assembly half rings 39a, 39b (FIG. 2).

[0038] In use, actuating the brake brake lever 11, for example by pulling it towards the handlebar tube 10 in a manner known per se, causes the brake brake lever 11 to rotate clockwise (FIG. 1), with which the (optionally provided) intermediate lever 22 also rotates clockwise. The wheel 21 rolls along the contoured surface 23 of the transmission lever 17, causing it to rotate counterclockwise and urging the piston 14 to the right, in the actuating direction towards the end of the handlebar, to push a quantity of brake fluid that fills the cavity 13 towards the port 16. Through the passage 18, the brake fluid makes a U-turn and is led into the flexible hose 20 from where it is directed towards the brake calipers (not shown) on the wheels of the vehicle.

[0039] The shape of the surface 23 of the transmission lever 17 on which the wheel 21 rolls can be variably designed in order to adjust the load / stroke curve of the piston as required. The inclination of the rolling surface 23 of the wheel can be adjusted, for example, to rotate the transmission lever 17 by a larger or smaller angle for the same rotation angle made by the intermediate lever 22, and thus to make the linear stroke of the piston 14 longer or shorter. This arrangement allows, for example, a larger or smaller stroke advance of the piston, which varies during the stroke of the piston, becoming less and less favorable as the brake control lever 11 is pulled, i.e. as it approaches its end-stroke. For example, the surface 23 can be variously inclined so as to configure the user to feel that the brake control lever 11 becomes less and less favorable as it approaches the handlebar tube during braking, with the same reaction force provided by the spring 19.

[0040] According to an embodiment (FIG. 4), the surface 23 of the transmission lever 17 may have a slight recess 23a, preferably with a curvature corresponding to that of the wheel 21, which recess 23a serves as a seat for a stable reception of the wheel 21 in the inoperative position of the brake. The recess 23a may be radial with a slight step 23b relative to the rest of the surface 23, which allows the user to obtain an ergonomically advantageous sensation of a jerk at the start of braking.

[0041] In addition to allowing adjustment of the longitudinal position of the cartridge 12 and cavity 13 relative to the piston 14, and therefore the length of the dead stroke, the adjustment screw 31 provides a stable shoulder surface which prevents the cartridge 12 from being ejected through the end (right side) of the handlebar tube 10 under the influence of the hydraulic thrust exerted by the piston 14 when it is actuated.

[0042] Although specific embodiments of the present invention have been disclosed, it should be understood that this disclosure is provided for illustrative purposes only and that the present invention is not limited thereby. Various modifications will be apparent to those skilled in the art in light of the foregoing examples. The scope of the present invention is limited only by the scope of the appended claims.

Claims

1. 1. A hydraulic brake control unit for a handlebar-steered vehicle having a handlebar tube (10) containing a hydraulic hose (20) therein, comprising: a cartridge (12) configured to be mounted within the handlebar tube (10), the cartridge (12) having a longitudinally extending cavity (13) formed therein with a port (16) at one end thereof; a piston (14) partially contained within said longitudinally extending cavity (13); a transfer lever (17) rotatably mounted on the handlebar tube (10) about a transverse axis (17a), the transfer lever (17) acting between the brake lever (11) and the piston (14) and exerting a first longitudinal thrust on the piston (14) towards the port (16); a flow passage (18) formed within the cartridge (12) and defining a U-shaped path for brake fluid, the flow passage (18) fluidly coupling the port (16) of the longitudinally extending cavity (13) with the hydraulic hose (20) and applying brake actuation pressure to brake fluid contained within the hydraulic hose (20) in a second longitudinal direction opposite the first longitudinal direction; A hydraulic brake control unit comprising:

2. 2. The hydraulic brake control unit according to claim 1, comprising a roller (21) rotatable about a transverse axis (21a) and attachable to the brake control lever (11), the roller (21) acting by rolling along a surface (23) of the transmission lever (17) when the brake control lever (11) is actuated.

3. 3. A hydraulic brake control unit according to claim 2, wherein the surface (23) of the transmission lever for rolling the roller (21) has a varying slope to provide a desired load / piston stroke diagram.

4. 4. A hydraulic brake control unit according to claim 2 or 3, wherein the surface (23) has a recess (23a) for stably receiving the roller (21) when the brake is in an inoperative state.

5. 2. A hydraulic brake control unit according to claim 1, comprising a stop element (26) securable to the handlebar tube (10) and cooperating with a portion (17b) of the transmission lever (17) to define an end-of-stroke position of the piston (14) from the side of the piston (14) furthest from the port (16).

6. 3. The hydraulic brake control unit according to claim 2, wherein the roller (21) can be mounted directly on the brake braking lever (11) or on an intermediate lever (22), the intermediate lever (22) can be mounted on the handlebar tube (10) or on the brake braking lever (11) so as to be rotatable about a transverse axis (22a), and the angular position of the intermediate lever (22) relative to the brake braking lever (11) can be adjusted by means of an adjustment screw (25).

7. 7. The hydraulic brake control unit according to claim 1, wherein the transfer lever (17) is formed as a rocker arm and has an arm (17c) configured to enter the handlebar tube (10) through an opening (10c) in the handlebar tube (10) and engage in thrust relationship with the end of the piston (14) furthest from the port (16).

8. 7. The hydraulic brake control unit of any one of claims 1, 2, 3, 5 and 6, wherein the cartridge (12) further defines an internal reservoir (27) for brake fluid.

9. 9. The hydraulic brake control unit of claim 8, wherein the cartridge (12) further defines an internal passage bore (28) that defines the internal reservoir (27) in fluid communication with the longitudinally extending cavity (13).

10. 7. The hydraulic brake control unit according to claim 1, further comprising a longitudinal adjustment screw (31) acting on an end of the cartridge (12) remote from the transmission lever (17) to adjust the longitudinal position of the cartridge (12) relative to the piston (14).

11. 11. The hydraulic brake control unit of claim 10, further comprising a rigid disc (33) mountable in a longitudinally fixed manner within the handlebar tube (10) and having a central threaded hole (32) in which the longitudinal adjustment screw (31) threadably engages.

12. 12. A hydraulic brake control unit as set forth in claim 11, further comprising a longitudinal locking element (35) having peripheral locking teeth (36) adapted to engage corresponding openings (37) formed in the handlebar tube (10), said longitudinal locking element (35) defining a longitudinally fixed shoulder surface adapted to resist displacement of the rigid disc (33).

13. 13. The hydraulic brake control unit of claim 12, wherein the longitudinal locking element (35) is at least partially aligned in cross section with the peripheral locking teeth (36) and has a central bore (38) capable of receiving a portion of the longitudinal adjusting screw (31).

14. A handlebar assembly for a handlebar-steered vehicle, comprising a handlebar tube (10) and a hydraulic brake control unit according to any one of claims 1, 2, 3, 5 and 6.

Images