Integrated handlebar and master cylinder having piston and hydraulic line coaxially aligned with major central axis of handlebar

[0002] This application claims the benefit of U.S. Provisional Application Ser. No. 60/175,537 filed Jan. 11, 2000.

[0003] The present invention is directed to the art of hydraulic master cylinder devices of the type adapted for manual actuation and, more particularly, to hydraulic hand brake apparatus. The present invention is particularly well suited for use in motorcycle hand brake and hydraulic clutch operations and will be described with particular reference thereto. However, it is to be appreciated that the present invention can be applied in a wide range of applications such as in the bicycle arts, motorized vehicle arts, or anywhere pressurized fluids are used to control one or more devices such as brakes, clutches or the like. Accordingly, the invention is not limited to the preferred embodiments described in detail below.

[0004] Drawings showing examples of prior art hydraulic master cylinders for use with motorcycles are shown in FIGS. 1-3. Generally, the hydraulic master cylinders have an integral piston adapted to be actuated by a lever provided adjacent to a handle grip which is positioned in a spaced apart relationship relative to motorcycle handlebars. FIG. 1 shows an end view of a master cylinder 1 mounted on the handlebar 2 using a bracket 3. FIG. 2 shows a master cylinder 1 positioned alongside of the handlebar 2 and a handle switching unit 4 mounted on the handlebar 2 coaxially therewith. A hydraulic line 5 extends from the master cylinder 1 in a spaced apart relationship relative to the handlebar 2 substantially as shown.

[0005] One disadvantage with typical prior art master cylinder devices is that they are constructed in a manner to provide little or no protection to the hydraulic fluid lines extending between the master cylinder and the actuation device. More particularly, as best illustrated in FIG. 2, the brake line 5 extends from the master cylinder 1 generally alongside the handlebar 2 in a substantially unprotected and rather vulnerable position. More particularly, as those skilled in the motorcycle or bicycle arts can appreciate, brake lines such as hydraulic fluid lines or cables often snag on clothing or other articles causing a potentially dangerous situation. Further, the generally unprotected nature of the brake lines 5 renders them vulnerable to severe mechanical damage, such as rupture, kinking, or the like, when they are exposed to excessive force or impact. This poses a particular problem in connection with high performance motorcycles and with motorcycles built for racing.

[0006] In addition to the above, another concern with prior art master cylinder and brake line arrangements is primarily aesthetic in nature. More particularly, external brake lines are not visually appealing. On some motorcycles, the brake lines are chrome plated or wire braided to provide a pleasant appearance. Even so, the external brake line routing detracts from the overall visual impact of the motorcycle. This is particularly true in custom motorcycles where external brake lines detract from the appearance of highly detailed frames, engines and other parts.

[0007] Another disadvantage with prior art motorcycle hydraulic master cylinder apparatus will be described below in connection with reference to FIG. 3. As shown there, a handlebar 6 defines a major central longitudinal axis 6. During use of the device shown in FIG. 3, a motorcycle operator places his palm onto the handlebar portion 6 and extends the forefingers around a trigger member 8. By squeezing on the trigger portion 8, rotation is established in the direction labeled by the arrow 9 in the Figure. An actuation foot member 10 moves together with the grip portion 8 substantially along a line 11 parallel to the major central axis 7 of the handlebar portion 6. In the configuration shown in FIG. 3, a piston (not shown) contained within the hydraulic master cylinder is linearly slidable along the line 11 substantially parallel but offset from the major access axis 7 of the handlebar portion.

[0008] One disadvantage with the system shown in FIG. 3 is that the piston within the master cylinder is slidable along an axis offset from the major axis of the handlebar portion. Accordingly, the overall hydraulic master cylinder system is generally bulky and therefore has a reduced aesthetic appeal. In addition to unnecessarily consuming space, the relative offset between the axis 11 defined by piston actuation and the hand grip portion 7 results in a mechanical disadvantage to the motorcycle rider.

[0009] In accordance with the above, therefore, it is desirable to provide an integrated handlebar and master cylinder having a piston and hydraulic line coaxially aligned with the central axis of the handlebar. Preferably, the piston is slidable along an axis coaxial and coincident with the major central axis of the hand grip portion of the motorcycle handlebar.

[0010] It would further be desirable to provide an integrated handlebar and master cylinder apparatus adapted for attachment to an associated handlebar, the master cylinder having a piston movable along an axis coaxial with an axis defined by the handlebar portion. Preferably, the axis defined by the handlebar portion together with the axis defined by the piston within the master cylinder is coaxial and coincident with the axis defined by the associated handlebar.

[0011] It would be desirable to provide a system such as described above so that a mechanical advantage is realized during manual actuation of the subject system.

[0012] Further, it would be desirable to provide a system such as described above to enable the routing of hydraulic brake lines or the like directly from the master cylinder and through at least the handlebar and top triple tree portions of a motorcycle. This simultaneously protects the brake lines from damage and is aesthetically pleasing.

[0013] The subject invention provides an integrated handlebar and master cylinder apparatus having a slidable piston and a hydraulic line both of which being coaxially aligned with the major central axis of a hand grip portion of the handlebar. The position of the piston within the subject system enables the piston to be linearly slidably directly along and coincident with the major central axis of the handlebar.

[0014] In addition, the subject invention provides an integrated handlebar and master cylinder device that includes a hydraulic line extending from the master cylinder substantially along an axis coaxial with and coincident with the major central axis of the handlebar. In that way, the hydraulic line is adapted for direct routing within the central cavity of the handlebar and motorcycle fork assemblies. This simultaneously provides protection to the hydraulic lines together with an improved aesthetic appearance.

[0015] The invention may take physical form in certain parts and arrangements of parts, the preferred embodiments of which will be described in detail in this specification and illustrated in the accompanying drawings which form apart hereof and wherein:

[0016] FIG. 1 is a front elevational view showing a conventional master cylinder disposed relative to a handlebar;

[0017] FIG. 2 is a top plan view showing another conventional master cylinder relative to a handlebar;

[0018] FIG. 3 is a top plan view showing another type of conventional master cylinder that is partially connected to the handlebar which is in turn attached to an associated motorcycle fork tube;

[0019] FIG. 4 is a perspective view of an integrated handlebar and master cylinder apparatus formed in accordance with a first preferred embodiment of the subject invention;

[0020] FIG. 5 is a top plan view in partial cross section showing the internal and external working parts of the subject invention and including an electric switch unit in accordance with a second preferred embodiment of the invention;

[0021] FIG. 6 is a side elevational view in partial cross section showing the internal working components of the master cylinder portion in accordance with the preferred embodiments of the invention;

[0022] FIG. 7 is an end elevational view showing actuation lever mount components and electrical switch box configuration in accordance with the preferred embodiments of the invention;

[0023] FIG. 8 is an end elevational view showing the electric switch box and clamp assembly with lever mounts omitted for clarity;

[0024] FIG. 9 is a top plan view in partial cross section showing the electrical switch box, clamp assembly, and lever configuration in accordance with a second preferred embodiment of the invention;

[0025] FIG. 10 is a front perspective view of the subject invention installed onto an associated motorcycle handlebar portion;

[0026] FIG. 11 is a perspective view of the subject invention in a position and orientation prior to installation onto an associated motorcycle handlebar portion and showing the preferred threaded interface portion of the invention;

[0027] FIG. 12 is a side perspective view of the subject invention installed onto an associated motorcycle handlebar showing the forward electrical switch box construction used with the second preferred embodiment of the invention; and,

[0028] FIG. 13 is a rear elevational view of the apparatus shown in FIG. 12 illustrating the position of the electrical switch box in accordance with the second preferred embodiment.

[0029] Referring now to the drawings wherein the showings are for the purposes of the illustrating the preferred embodiments of the invention only and not for purposes of limiting same, the overall arrangement of the preferred form of an integrated handlebar and master cylinder apparatus formed in accordance with the invention can best be seen with reference first to FIG. 4. As shown there, the subject integrated handlebar and master cylinder device 50 includes a brake master cylinder portion 52, formed integrally with a hand grip portion 54 adapted for direct connection onto an associated handlebar section 56 through a threaded interface 58. As can be seen, an actuating lever 60 extends from the subject system 50 and is pivotably attached thereto in a manner well known in the art. A hydraulic brake line 62 extends from the master cylinder portion 52 and hand grip portion 54 substantially coaxially with and coincident with the major central axis 62 defined by the hand grip portion 54 and the associated handlebar section 56. In addition, as shown in FIG. 4, a hydraulic piston 64 is linearly slidably within a cylindrical sleeve of the master cylinder along the major central axis 64 of the handlebar section 56 and the hand grip portion 54.

[0030] With reference next to FIGS. 5 and 6 of the drawings, there are shown a more detailed views of the first embodiment of the invention. Associated motorcycle portion shown fragmentarily in FIG. 5 includes a pair of transversely mounted fork tubes of which only the righthand fork tube 66 is shown in FIG. 5. The front forks are secured integrally to a top bridge shown at 68 in FIG. 5. A handlebar 56 is fitted with a collar member 69 welded in place. A first lower end of the handlebar is externally threaded for a washer face nut 70. After the handlebar is placed through a suitable receiving hole formed in the top bridge shown at 2 in FIG. 5, the washer face nut 70 is tightened to secure the handlebar in the position shown. The handlebar is internally threaded on the opposite or upper end to accept the subject device 50 of the invention at a threaded interface 72.

[0031] A more detailed view is shown in FIG. 6. A brake master cylinder 52 has a body formed integrally with a hand grip portion 54 by casting or machining from billet material. The body 52 has a upper portion, which defines an oil reservoir 74 and a lower portion which defines a cylindrical chamber 76 adjacent to the front end thereof. The reservoir 74 and the chamber 76 are in fluid communication with each other by ports 80 and 82. A cover member 84 having a flexible diaphragm 86 attached thereto is secured to the top of the reservoir 74 by any suitable means, preferably using screws 88. The diaphragm 86 is vertically movable in response to changes in the quantity of oil in the reservoir 74 to maintain a constant pressure in the reservoir.

[0032] A master cylinder piston 90 is linearly slidably positioned in the cylindrical chamber 76. As shown, the piston 90 is linearly slidable along an axis coaxial with and coincident with the major central axis 64 defined by the handlebar 56 portion and the hand grip portion 54. A return spring 92 is provided in the cylindrical chamber 76 between the bottom thereof and the piston 90. A seal cap 94 is disposed between the piston 90 and the spring 92 to maintain oil tightness in the cylindrical chamber 76. The piston 90 is provided with a radially outwardly projecting flange opposite the seal cap 94 end of the piston. A seal ring 96 is disposed inwardly of the flanges in contact with the piston and the peripheral wall of the cylindrical chamber 76.

[0033] With reference now to FIGS. 5 and 7, bracket upper and lower portions 100, 102 are provided on one side of the body 52 and are preferably integrally formed with the body 52 as illustrated. An actuating lever 60 has a base portion 104 which is rotatably or pivotably connected to the bracket 100, 102 by suitable pin or bolt means 106 which is threaded preferably directly into the lower bracket 102 (FIG. 7). The lever 60 has a pressing leg 108 which projects from its base portion 104 and which is in abutment against the pressing area 110 of the piston 90.

[0034] A handle switching unit 120 contains an electrical switch for a turn signal and a starter switch 122. The handle switching unit 120 is mounted on the handlebar/master cylinder adjacent to the master cylinder 52 as shown in FIGS. 5, 7, 8. An integral handlegrip 54 is provided on the free end of the hand grip portion 124 as shown in FIG. 5. Space is provided for a throttle assembly 126 on one unit as shown in FIG. 5.

[0035] A clamp 128 shown in (FIGS. 5, 7, 8) for securing the master cylinder 52 to the handlebar 56 is provided to lock the master cylinder in place after it is threaded into the handlebar. The clamp is slid onto the handlebar before the master cylinder is fastened onto the handlebar and connected to the hydraulic split line 62 as shown in FIGS. 5, 6. The clamp is then tightened down with a bolt or a mirror stem 130, shown in FIG. 8.

[0036] The port 80 (FIG. 6) defines an orifice through which oil is supplied from the reservoir 74 into the cylinder chamber 76. The port 82 which is provided adjacent to the port 80, defines a relief port which serves to relieve the pressure of the oil in the reservoir 74 and the pressure of the oil in the cylinder chamber 76.

[0037] When the boot portion 108 of lever 60 is depressed against master cylinder piston area 110 (FIGS. 5, 7) by pivotal motion of the lever about the bolt 106, the piston 90 is urged into slidable motion along the axis 64 to force the oil (not shown) in chamber 76 through passage 132FIG. 6, and through the hydraulic line 62, threaded into master cylinder unit at 134 as shown in FIG. 6, to an associated brake or clutch assembly (not shown).

[0038] A right hand unit is shown and is usually used in motorcycle applications for the brake assembly. Typically, two master cylinder units of the type described are used per motorcycle. The left hand assembly is used to operate clutch hydraulics and is a mirror image of the right hand assembly in all aspects except for the master cylinder piston assembly which is smaller in diameter for more hydraulic power and less needed travel. Also, these controls may be threaded into many styles of handlebars. With this invention, the controls are compact in size and hide the hydraulic lines while protecting them.

[0039] The invention has been described with reference to the preferred embodiments. Obviously, modifications and alterations will occur to others upon a reading and understanding of this specification. It is intended to include all such modifications and alterations. As an example, in one such modification, the subject invention is adapted for integration into a motorcycle foot peg for foot operated brake controls. In that embodiment of the subject invention, and integrated foot peg and master cylinder apparatus is provided having a piston and hydraulic line coaxially aligned with the major central axis of a motorcycle foot peg.