Bicycle hydraulic operating device

A bicycle hydraulic operating device comprises a bracket, a hydraulic cylinder, a piston, a lever, a fluid reservoir, and a lid. The bracket is configured to be mounted to a bicycle handlebar. The piston is movably disposed within the hydraulic cylinder. The lever is pivotally provided around a pivot axis relative to the bracket and is operatively coupled to the piston to move the piston within the hydraulic cylinder in response to pivotal movement of the lever. The fluid reservoir is disposed on the bracket and having an opening configured to face substantially in a downward direction in a state where the bracket is mounted to the bicycle handlebar. The lid is configured to cover the opening of the fluid reservoir.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a bicycle hydraulic operating device.

2. Discussion of the Background

Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle. In recent years, some bicycles have been provided with a bicycle hydraulic system. The bicycle hydraulic system includes a hydraulic operating mechanism and a hydraulically actuated component, for example.

SUMMARY OF THE INVENTION

In accordance with a first aspect of the present invention, a bicycle hydraulic operating device comprises a bracket, a hydraulic cylinder, a piston, a lever, a fluid reservoir, and a lid. The bracket is configured to be mounted to a bicycle handlebar. The piston is movably disposed within the hydraulic cylinder. The lever is pivotally provided around a pivot axis relative to the bracket and is operatively coupled to the piston to move the piston within the hydraulic cylinder in response to pivotal movement of the lever. The fluid reservoir is disposed on the bracket and has an opening configured to face substantially in a downward direction in a state where the bracket is mounted to the bicycle handlebar. The lid is configured to cover the opening of the fluid reservoir.

In accordance with a second aspect of the present invention, the bicycle hydraulic operating device according to the first aspect is configured so that the lid is disposed between the fluid reservoir and the lever.

In accordance with a third aspect of the present invention, the bicycle hydraulic operating device according to the second aspect is configured so that the lid is disposed between the fluid reservoir and the pivot axis of the lever.

In accordance with a fourth aspect of the present invention, the bicycle hydraulic operating device according to the first aspect is configured so that the lever includes a first end portion and a second end portion opposite to the first end portion. The pivot axis is provided closer to the first end portion than to the second end portion. The lid is disposed between the fluid reservoir and the first end portion.

In accordance with a fifth aspect of the present invention, the bicycle hydraulic operating device according to the first aspect further comprises a flexible diaphragm disposed between the lid and the opening of the fluid reservoir.

In accordance with a sixth aspect of the present invention, the bicycle hydraulic operating device according to the first aspect is configured so that the bracket includes a mounting member configured to mount the bracket to the bicycle handlebar. The hydraulic cylinder is disposed on the bracket between the pivot axis of the lever and the mounting member.

In accordance with a seventh aspect of the present invention, the bicycle hydraulic operating device according to the first aspect further comprises an electric switch unit provided on the lever and configured to be electrically connected to a bicycle electric component.

In accordance with an eighth aspect of the present invention, the bicycle hydraulic operating device according to the first aspect further comprises a bleeding port configured to communicate with the fluid reservoir.

In accordance with a ninth aspect of the present invention, the bicycle hydraulic operating device according to the eighth aspect is configured so that the bleeding port is configured to face substantially in an upward direction in a state where the bracket is mounted to the bicycle handlebar.

In accordance with a tenth aspect of the present invention, a bicycle hydraulic operating device comprises a bracket, a lever supporting portion, a hydraulic cylinder, a piston, a lever, a fluid reservoir, and a lid. The bracket is configured to be mounted to a bicycle handlebar. The lever supporting portion has a receiving space. The piston is movably disposed within the hydraulic cylinder. The lever is pivotally provided around a pivot axis relative to the bracket and is partially disposed at the receiving space. The lever is operatively coupled to the piston to move the piston within the hydraulic cylinder in response to pivotal movement of the lever. The fluid reservoir is disposed on the bracket and has an opening configured to face the receiving space. The lid is configured to cover the opening of the fluid reservoir.

In accordance with an eleventh aspect of the present invention, a bicycle hydraulic operating device comprises a bracket, a hydraulic cylinder, a piston, a lever, a fluid reservoir, and a lid. The bracket is configured to be mounted to a bicycle handlebar. The piston is configured to be movably provided within the hydraulic cylinder. The lever is pivotally provided about a pivot axis relative to the hydraulic cylinder and is operatively coupled to the piston to move the piston within the hydraulic cylinder in response to pivotal movement of the lever. The fluid reservoir is disposed on the bracket and having an opening. The lid is configured to cover the opening of the fluid reservoir and is provided between the fluid reservoir and the brake lever.

DESCRIPTION OF THE EMBODIMENTS

Referring initially toFIG. 1, a bicycle hydraulic operating device10in accordance with the embodiment is configured to operate a bicycle hydraulic brake device (not shown) and is configured to be mounted to a bicycle handlebar100. The bicycle handlebar100is a dropdown bicycle handlebar, for example. The bicycle hydraulic operating device10is a right hand side control device operated by the rider's right hand to operate the hydraulic brake device and a shifting device (not shown, e.g., an electric rear derailleur or a hub transmission). It will be apparent to those skilled in the bicycle field that the configuration of the bicycle hydraulic operating device10can be adapted to a left hand side control device that is operated by the rider's left hand. In this embodiment, the following directional terms “forward”, “rearward”, “left”, “right”, “upward” and “downward” as well as any other similar directional terms refer to those directions which are determined on the basis of the rider who sits on a saddle (not shown) of a bicycle with facing the handlebar100. Accordingly, these terms, as utilized to describe the bicycle hydraulic operating device10should be interpreted relative to a bicycle equipped with the bicycle hydraulic operating device10as used in an upright riding position on a horizontal surface.

As seen inFIG. 1, the bicycle hydraulic operating device10is mounted to a curved section102of the bicycle handlebar100. In other words, the bicycle hydraulic operating device10is particularly designed for a bicycle that is equipped with the dropdown bicycle handlebar such as the bicycle handlebar100. However, it will be apparent to those skilled in the bicycle field from this disclosure that the bicycle hydraulic operating device10could be applied to different types of handlebars if needed and/or desired. As explained below, the bicycle hydraulic operating device10includes both a braking function and a shifting function in a single unit. However, it will be apparent to those skilled in the bicycle field from this disclosure that the shifting function could be eliminated from the bicycle hydraulic operating device10if needed and/or desired. The bicycle hydraulic operating device10is a bicycle hydraulic brake operating device to operate the bicycle hydraulic brake device. However, it will be apparent to those skilled in the bicycle field from this disclosure that the technology disclosed herein can be applied to hydraulic systems of bicycle components other than the bicycle hydraulic brake operating device.

As illustrated inFIG. 1, the bicycle hydraulic operating device10comprises a bracket14, a grip cover38, a front cover39, and a lever18. The bracket14is configured to be mounted to the bicycle handlebar100. In the illustrated embodiment, the grip cover38and the front cover39are attached to the bracket14to at least partially cover the bracket14. The lever18is pivotally provided around a pivot axis P relative to the bracket14. As explained below, the lever18is biased to a rest position with respect to the bracket14. Thus, the lever18moves relative to the bracket14from the rest position along a brake operating path BA. The lever18actuates a hydraulic system (described later) upon movement of the lever18relative to the bracket14to perform a braking operation of the hydraulic brake device (not shown).

As seen inFIG. 1, the bicycle hydraulic operating device10further includes an electric switch unit25. The electric switch unit25is provided on the lever18and is configured to be electrically connected to a bicycle electric component such as the shifting device (not shown). In the illustrated embodiment, the electric switch unit25includes a pair of operating members24and26configured to perform chain or gear shifting operations of the shifting device (not shown). The operating members24and26are electrically connected to a control unit (not shown). The operating members24and26are constructed as shown in U.S. Patent Application Publication No. 2009/0031841 A1 (assigned to Shimano, Inc.), for example. It will be apparent to those skilled in the bicycle field that the electric switch unit25can be eliminated from the bicycle hydraulic operating device10if needed and/or desired. Furthermore, it will be apparent to those skilled in the bicycle field that the operating members24and26are not limited to the illustrated structure and arrangement, but rather other suitable structures and arrangements can be used as needed and/or desired. The control unit is a microcomputer that is located in the bracket14, for example. However, the control unit can be remotely located if needed and/or desired. Since various electrical shifting systems are known in the bicycle field, the operating members24and26and the control unit will not be discussed herein for the sake of brevity.

As illustrated inFIG. 1, the bracket14includes a mounting member20configured to mount the bracket14to the bicycle handlebar100.

As illustrated inFIG. 1, the mounting member20is a handlebar clamp that is configured to be attached to the bracket14for releasably securing the bracket14to the curved section102of the bicycle handlebar100. In the illustrated embodiment, the mounting member20is coupled to a handlebar attachment portion30of the bracket14and includes a band21. The handlebar attachment portion30is arranged at an opposite side of the lever18and contacts the curved section102of the bicycle handlebar100when a fastener (not shown) is tightened to move the band21towards the handlebar attachment portion30. It will be apparent to those skilled in the bicycle field that the mounting member20that is not limited to the illustrated clamp, but rather other suitable attachment mechanisms can be used as needed and/or desired.

Referring now toFIG. 2, the grip cover38and the front cover39are removably attached to the bracket14. The grip cover38is removably attached to the bracket14to cover at least an upper surface and lateral side surfaces of the bracket14. The front cover39is removably attached to bracket14to cover a front surface of the bracket14. The bracket14includes the handlebar attachment portion30, a gripping portion32and a pommel portion34. The bracket14is made of a rigid and hard material. The gripping portion32is located at a substantially middle portion of the bracket14. The pommel portion34is located at a forward free end of the bracket14. In other words, the gripping portion32is disposed between the handlebar attachment portion30and the pommel portion34along a longitudinal axis of the bracket14that is substantially parallel to a longitudinal axis of a bicycle in a state where the bracket14is mounted to the bicycle handlebar100attached to a bicycle. More specifically, the pommel portion34is located forward of the bracket14relative to a transition point on a top surface36of the bracket14in a state where the bracket14is mounted to the bicycle handlebar100.

In the illustrated embodiment, the handlebar attachment portion30, the gripping portion32and the pommel portion34are integrally provided as a one-piece unitary member. Of course, the handlebar attachment portion30, the gripping portion32and the pommel portion34can have removable members as needed and/or desired. For example, an outer panel of the control unit can defines a part of the gripping portion32.

As illustrated inFIG. 2, the grip cover38is stretched over the gripping portion32and a part of the pommel portion34to provide a cushion to the gripping portion32of the bracket14and to provide an attractive appearance. The front cover39is attached to a front portion of the pommel portion34to cover a bleeding plug41provided on the pommel portion34. Typically, the grip cover38is made of elastic material such as rubber. The front cover39is made of a rigid and hard material such as synthetic resin. However, it will be apparent to those skilled in the bicycle field that materials of the grip cover38and the front cover39are not limited to rubber and synthetic resin respectively and any appropriate materials can be applied to the grip cover38and the front cover39if needed and/or desired.

As illustrated inFIG. 2, the bracket14further includes a lever supporting portion15. The lever18is pivotally supported by the lever supporting portion15around a pivot axis P defined by a pivot pin22relative to the bracket14. The lever supporting portion15has a receiving space46in which the lever18is pivotally supported around the pivot axis P. The lever supporting portion15includes a pair of supporting walls47aand47bspaced apart from each other along the pivot axis P. The pivot pin22is secured to the supporting walls47aand47b. The receiving space46is defined between the supporting walls47aand47b. The lever18is partially disposed at the receiving space46. More specifically, the lever18includes a first end portion18aand a second end portion18bopposite to the first end portion18a. The pivot axis P is provided closer to the first end portion18athan to the second end portion18b. The first end portion18ais provided in the receiving space46between the supporting walls47aand47b. The second end portion18bis provided outside the receiving space46. A front section of the receiving space46is covered by the front cover39.

Referring toFIG. 3, the bicycle hydraulic operating device10further comprises a hydraulic cylinder56, a piston58, a biasing element62and a fluid reservoir tank54. The hydraulic cylinder56, the piston58, the biasing element62and the fluid reservoir tank54constitute the hydraulic system of the bicycle hydraulic operating device10. The hydraulic cylinder56is disposed on the bracket14between the pivot axis P of the lever18and the mounting member20in a longitudinal direction of the bracket14. In the illustrated embodiment, the hydraulic cylinder56is provided in the gripping portion32of the bracket14and is integrally provided in the gripping portion32of the bracket14as a one-piece unitary member.

The piston58is movably disposed within the hydraulic cylinder56. More specifically, the hydraulic cylinder56includes a cylinder bore60extending along the longitudinal axis of the bracket14. The cylinder bore60is open to the receiving space46. The piston58is movable disposed within the cylinder bore60in a reciprocal manner in response to operation of the lever18. The piston58and the internal surface of the cylinder bore60define a cylinder chamber61of the hydraulic cylinder56. The biasing element62is disposed in the cylinder bore60for biasing the piston58to a rest position. In the illustrated embodiment, the biasing element62is a coil compression spring (return spring) that also biases the lever18to its rest position as seen inFIG. 3. The hydraulic cylinder56has an outlet port66that extends from the cylinder bore60to a hydraulic hose connector (not shown).

As seen inFIG. 3, the lever18is operatively coupled to the piston58to move the piston58within the hydraulic cylinder56in response to pivotal movement of the lever18. More specifically, the lever18is operatively connected to the piston58by a connecting rod64. The connecting rod64is connected to the lever18with a reach adjustment connection such that a distance between the piston58and the lever18is adjustable. The reach adjustment connection between the connecting rod64and the lever18is substantially similar in construction to the reach adjustment connection that is disclosed in U.S. Patent Application Publication No. 2011/0147149 A1 (assigned to Shimano, Inc.), for example.

As the lever18is pivoted around the pivot axis P relative to the bracket14, the piston58moves within the cylinder bore60of the hydraulic cylinder56against the force of the biasing element62to force hydraulic fluid out of the cylinder bore60through the outlet port66. Operation of the lever18causes hydraulic fluid to move from the hydraulic cylinder56to a slave piston or pistons (not shown) in the hydraulic brake device (e.g., hydraulic disc brake caliper or hydraulic rim brake caliper) so as to apply frictional resistance and causing the bicycle to slow down or stop. Of course, the bicycle hydraulic operating device10can be applied to any kind of a hydraulic disc brake system.

As illustrated inFIG. 3, the fluid reservoir tank54is disposed above the pivot axis P of the lever18in a state where the bracket14is mounted to the bicycle handlebar100. The fluid reservoir tank54is disposed above the hydraulic cylinder56in the pommel portion34of the bracket14. Of course, it will be apparent to those skilled in the bicycle field from this disclosure that a location of the fluid reservoir tank54is not limited to the illustrated location, but rather other suitable locations can also be used.

As illustrated inFIG. 3, the fluid reservoir tank54includes a fluid reservoir70, a lid72, and a flexible diaphragm74. The fluid reservoir70is disposed on the bracket14and has an opening82configured to face substantially in a downward direction D2in a state where the bracket14is mounted to the bicycle handlebar100. In the illustrated embodiment, the fluid reservoir70is provided in the pommel portion34of the bracket14. The fluid reservoir70is integrally provided in the pommel portion34of the bracket14as a one-piece unitary member. The fluid reservoir70is provided as a recess being substantially recessed in an upward direction D1and open substantially in the downward direction D2in a state where the bracket14is mounted to the bicycle handlebar100. The opening82is disposed at a lower portion of the fluid reservoir70in a state where the bracket14is mounted to the bicycle handlebar100. As illustrated inFIG. 3, the hydraulic cylinder56and the fluid reservoir70are integrally provided as a part of a one-piece unitary member. In other words, the hydraulic cylinder56and the fluid reservoir70are integrally provided with the bracket14as a one-piece unitary member.

The opening82of the fluid reservoir70is configured to face the receiving space46. More specifically, the opening82of the fluid reservoir70is disposed to face the first end portion18aof the lever18. The lid72is configured to cover the opening82of the fluid reservoir70and is disposed between the fluid reservoir70and the lever18. More specifically, the lid72is disposed between the fluid reservoir70and the first end portion18aof the lever18. Further, the lid72is disposed between the fluid reservoir70and the pivot axis P of the lever18.

The lid72is attached to the fluid reservoir70together with the flexible diaphragm74to cover the opening82and the flexible diaphragm74. The flexible diaphragm74is disposed between the lid72and the opening82of the fluid reservoir70. The flexible diaphragm74includes a protruding part74athat extends into the fluid reservoir70. A hydraulic fluid chamber78is defined between the fluid reservoir70and the flexible diaphragm74and is configured to reserve hydraulic fluid therein.

As illustrated inFIG. 3, the hydraulic fluid chamber78of the fluid reservoir tank54is in fluid communication with the cylinder chamber61of the hydraulic cylinder56via an internal passageway80. The internal passageway80is provided in the bracket14to fluidly connect the hydraulic fluid chamber78of the fluid reservoir tank54to the cylinder chamber61of the hydraulic cylinder56. The internal passageway80includes an enlarged area89. The enlarged area89is disposed closer to the cylinder chamber61of the hydraulic cylinder56than to the hydraulic fluid chamber78of the fluid reservoir tank54in the internal passageway80. A removable plate90is fixedly coupled to the bracket14to cover or seal the enlarged area89. The enlarged area89includes a timing port86and a compensation port88, both of which are in fluid communication with the cylinder chamber61of the hydraulic cylinder56. The internal passageway80is in fluid communication with the cylinder chamber61of the hydraulic cylinder56via the timing port86and the compensation port88provided in the enlarged area89. The functions of the timing port86and the compensation port88are well known and will not be described further.

As illustrated inFIG. 4, the lid72and the flexible diaphragm74are attached to the fluid reservoir70with screws76to cover the opening82. The flexible diaphragm74and the lid72are provided in the receiving space46defined between the supporting walls47aand47bof the lever supporting portion15. The bicycle hydraulic operating device10further comprises a bleeding port44provided on the pommel portion34. The bleeding port44is configured to communicate with the fluid reservoir70. The bleeding port44is provided as a funnel mounting portion to which an oil funnel (not shown) is configured to be mounted for adding hydraulic fluid into or for bleeding air from the hydraulic system of the bicycle hydraulic operating device10. In the illustrated embodiment, the bleeding port44is disposed on the bracket14at a location primarily forward of the pivot axis P of the lever18in a state where the bracket14is mounted to the bicycle handlebar100. The bleeding plug41is screwed in the bleeding port44. It will be apparent to those skilled in the bicycle field from this disclosure that a location of the bleeding port44is not limited to the illustrated location, but rather other suitable locations can also be used. The bleeding port44can be disposed on lateral side faces of the bracket14at the pommel portion34, for example.

Referring toFIG. 5, the bleeding port44has an outer end opening94provided at the uppermost portion of the bracket14. The outer end opening94of the bleeding port44is open into an external space outside the bracket14. As illustrated inFIG. 6, the bleeding port44is provided in a first inner wall surface70aof the fluid reservoir70. The bleeding port44has an inner end opening95provided in the first inner wall surface70a. The inner end opening95of the bleeding port44is opposite to the outer end opening94(FIG. 5) and is open into the fluid reservoir70(the hydraulic fluid chamber78). Thus, the bleeding port44fluidly connects the hydraulic fluid chamber78of fluid reservoir70with the external space outside the bracket14. The fluid reservoir70includes a ceiling surface70b.

As illustrated inFIG. 6, the lever supporting portion15has an attachment surface81which has a flat shape and is disposed around the opening82to define the opening82. The inner end opening95is closer to the attachment surface81than to the ceiling surface70bof the fluid reservoir70. The attachment surface81is provided in the receiving space46between the supporting walls47aand47bof the lever supporting portion15. The lid72and the flexible diaphragm74are attached to the attachment surface81.

As illustrated inFIG. 5, the internal passageway80is provided in a second inner wall surface70cand is disposed on an opposite side of the bleeding port44with respect to the fluid reservoir70. The internal passageway80includes an end opening96provided in the second inner wall surface70c. The end opening96of the internal passageway80is open into the fluid reservoir70(the hydraulic fluid chamber78). Further, the end opening96is closer to the attachment surface81than to the ceiling surface70bof the fluid reservoir70.

As illustrated inFIG. 7, the bleeding port44is provided above the opening82and is configured to face substantially in the upward direction D1in a state where the bracket14is mounted to the bicycle handlebar100. The bleeding port44extends substantially in the upward direction D1from the hydraulic fluid chamber78(the fluid reservoir70). The phrase “the bleeding port44is configured to face substantially in an upward direction D1” can encompass that the direction D5in which the bleeding port44faces is inclined with respect to the upward direction D1as well as that the direction D5is the same as the upward direction D1. Namely, the phrase “the bleeding port44is configured to face substantially in an upward direction D1” can encompass that the direction D5includes a horizontal component D51and an upward component D52which is directed in the same direction as the upward direction D1.

The direction D5in which the bleeding port44faces can be defined as a direction which is parallel to a center line C1of the bleeding port44and which is directed to an opposite side of the fluid reservoir70. The bleeding port44extends along the center line C1. The center line C1of the bleeding port44is inclined with respect to the vertical direction (the upward direction D1). It will be apparent to those skilled in the bicycle field that the direction D5of the bleeding port44can be parallel to the upward direction D1and can be inclined with respect to the upward direction D1. The outer end opening94of the bleeding port44is open substantially in the upward direction D1. The outer end opening94and the inner end opening95of the bleeding port44are disposed above the opening82of the fluid reservoir70.

As seen inFIG. 7, the opening82is configured to face substantially in the downward direction D2in a state where the bracket14is mounted to the bicycle handlebar100. The opening82is configured to face the receiving space46defined between the supporting walls47aand47bof the lever supporting portion15in a state where the bracket14is mounted to the bicycle handlebar100. As well as the opening82, the attachment surface81is provided to face substantially in the downward direction D2and provided to face the receiving space46in a state where the bracket14is mounted to the bicycle handlebar100. The attachment surface81is inclined relative to a vertical direction (the upward direction D1and the downward direction D2) in a state where the bracket14is mounted to the bicycle handlebar100.

The phrase “the opening82is configured to face substantially in the downward direction D2” can encompass that the direction D6in which the opening82faces is inclined with respect to the downward direction D2as well as that the direction D6is the same as the downward direction D2. Namely, the phrase “the opening82is configured to face substantially in the downward direction D2” can encompass that the direction D6includes a horizontal component D61and a downward component D62which is directed in the same direction as the downward direction D2. The direction D6in which the opening82faces can be defined as a direction which is perpendicular to a virtual surface V1defined by the opening82and which is directed to an opposite side of the fluid reservoir70with respect to the opening82, for example. In the illustrated embodiment, the virtual surface V1is parallel to the attachment surface81, and the attachment surface81is provided on the virtual surface V1. It will be apparent to those skilled in the bicycle field that the direction D6of the opening82can be parallel to the downward direction D2and can be inclined with respect to the downward direction D2.

The ceiling surface70bis provided to face substantially in the downward direction D2in a state where the bracket14is mounted to the bicycle handlebar100. The ceiling surface70bis provided along the top surface36of the bracket14(the top surface36of the pommel portion34). The ceiling surface70bis curved along the top surface36of the pommel portion34and has a curved shape such that a front end of the ceiling surface70bis higher than a rear end of the ceiling surface70b. As seen inFIG. 7, a distance H1between the attachment surface81and the front end of the ceiling surface70bis greater than a distance H2between the attachment surface81and the rear end of the ceiling surface70bwhen viewed from a direction of the pivot axis P. The ceiling surface70band the first inner wall surface70aare disposed above the second inner wall surface70cand the opening82in a state where the bracket14is mounted to the bicycle handlebar100.

As illustrated inFIG. 8, the protruding part74aof the flexible diaphragm74is provided in the fluid reservoir70. The flexible diaphragm74is made of elastic material such as rubber to be deformable in the fluid reservoir70. The flexible diaphragm74and the lid72are attached to the attachment surface81of the lever supporting portion15with the screws76(FIG. 4) to cover the opening82.

As illustrated inFIGS. 9A and 9B, the flexible diaphragm74includes the protruding part74a, a flange part74b, and a thinner part74c. The flange part74bhas a plate shape and is configured to contact the attachment surface81. The flange part74bis provided around an outer periphery of the thinner part74c. The thinner part74chas a plate shape and is provided within the flange part74b. A thickness of the thinner part74cis smaller than a thickness of the flange part74b. The protruding part74aprotrudes from the thinner part74cand provides a slit or recess at the receiving space46side of the thinner part74c. A thickness of the protruding part74ais substantially the same as the thickness of the thinner part74cand smaller than the thickness of the flange part74b. The protruding part74aand the thinner part74care deformable to change the capacity of the hydraulic fluid chamber78.

As illustrated inFIG. 8, the flange part74bis provided between the attachment surface81and the lid72. The lid72has a plate shape and is made of metallic material such as aluminum alloy or iron. The lid72and the flange part74bare inclined relative to the vertical direction (the upward direction D1and the downward direction D2) in a state where the bracket14is mounted to the bicycle handlebar100, as well as the attachment surface81. The lid72and the flange part74bare disposed along the attachment surface81. The lid72and the flange part74bare disposed substantially along the top surface36of the pommel portion34of the bracket14.

Referring toFIG. 10, the protruding part74aof the flexible diaphragm74is disposed at a substantially middle position in the hydraulic fluid chamber78(the fluid reservoir70) in a transverse direction D3defined along the pivot axis P. The ceiling surface70bis provided on an opposite side of the top surface36of the bracket14(the top surface36of the pommel portion34) and is curved along the top surface36of the pommel portion34. The ceiling surface70bhas a curved shape such that a transverse center of the ceiling surface70bis higher than transverse ends of the ceiling surface70b. A distance H3between the attachment surface81and the transverse center of the ceiling surface70bis greater than a distance H4between the attachment surface81and the transverse ends of the ceiling surface70b. The protruding part74aof the flexible diaphragm74is disposed under the transverse center of the ceiling surface70b.

As seen inFIG. 8, when the hydraulic fluid is added into the hydraulic system of the bicycle hydraulic operating device10, the front cover39is removed from the bracket14, and the bleeding plug41is removed from the bleeding port44. An oil funnel (not shown) is attached to the bleeding port44from the outer end opening94. When the hydraulic fluid is added into the hydraulic system of the bicycle hydraulic operating device10from the oil funnel, the outer end opening94of the bleeding port44serves as an inlet of the fluid reservoir tank54for bleeding hydraulic fluid into the cylinder bore60. In this case, the hydraulic fluid flows into the cylinder bore60via the bleeding port44, the fluid reservoir tank54and the internal passageway80. Furthermore, the hydraulic fluid drains out of the outlet port66(FIG. 3) towards the bicycle brake device that is fluidly coupled to the bicycle hydraulic operating device10via the hydraulic hose (not shown).

On the other hand, when the hydraulic fluid is added into the hydraulic system of the bicycle hydraulic operating device10from the hydraulic brake device via the hydraulic hose or when the air in the hydraulic system is bled out of the hydraulic system, the outer end opening94of the bleeding port44serves as an outlet of the fluid reservoir tank54for bleeding hydraulic fluid into the cylinder bore60from the hydraulic hose or for bleeding air out of the hydraulic system. In this case, when the hydraulic fluid is added to the hydraulic system from a bleed nipple of the hydraulic brake device using a syringe (not shown), the hydraulic fluid flows into the fluid reservoir tank54via the hydraulic hose, the outlet port66, the cylinder bore60and the internal passageway80to fill the fluid reservoir tank54. Excess hydraulic fluid of the fluid reservoir tank54overflows out of the outer end opening94of the bleeding port44into the oil funnel. Furthermore, air included in the hydraulic fluid in the hydraulic system is also bled from the outer end opening94of the bleeding port44.

With the bicycle hydraulic operating device10according to the embodiment, since the opening82of the fluid reservoir70is configured to face substantially in the downward direction D2in a state where the bracket14is mounted to the bicycle handlebar100, it is possible to adjust an upper shape of the fluid reservoir70to the outer shape (e.g., the top surface36of the bracket14) of the bicycle hydraulic operating device10. Accordingly, an interior of the bicycle hydraulic operating device10can be effectively utilized, which allows the bicycle hydraulic operating device10to be more compact.

With the bicycle hydraulic operating device10according to the embodiment, since the opening82of the fluid reservoir70is configured to face the receiving space46, the receiving space46can be effectively utilized as a space in which the lid72is disposed. Accordingly, an interior of the bicycle hydraulic operating device10can be effectively utilized, which allows the bicycle hydraulic operating device10to be more compact.

Furthermore, with the bicycle hydraulic operating device10according to the embodiment, since the lid72is disposed between the fluid reservoir70and the lever18, the space between the fluid reservoir70and the lever18can be effectively utilized. Accordingly, an interior of the bicycle hydraulic operating device10can be effectively utilized, which allows the bicycle hydraulic operating device10to be more compact.

In understanding the scope of the present invention, as used herein to describe the above embodiment(s), the following directional terms “forward”, “rearward”, “left”, “right”, “upward” and “downward” as well as any other similar directional terms refer to those directions which are determined on the basis of the rider who sits on a saddle (not shown) of a bicycle with facing a handlebar of the bicycle. Accordingly, these terms, as utilized to describe the bicycle hydraulic operating device should be interpreted relative to a bicycle equipped with the bicycle hydraulic operating device as used in an upright riding position on a horizontal surface.

The term “comprising” and its derivatives, as used herein, are intended to be open ended terms that specify the presence of the stated features, elements, components, groups, integers, and/or steps, but do not exclude the presence of other unstated features, elements, components, groups, integers and/or steps. This definition also applies to words of similar meaning, for example, the terms “have”, “include” and their derivatives.

The terms “member”, “section,” “portion,” “part” or “element” when used in the singular can have the dual meaning of a single part or a plurality of parts.