Abstract:
A brake control device is provided for connecting to a hydraulic fluid conduit, wherein the hydraulic fluid conduit has a first end for connecting to the brake control device and a second end for connecting to a braking apparatus. The brake control device comprises a bracket that can be mounted to a handlebar of the bicycle, a brake operating member that is movably coupled to the bracket, and a hydraulic fluid transmission unit disposed on the bracket. The hydraulic fluid transmission unit is structured to communicate a hydraulic fluid to the hydraulic fluid conduit in response to movement of the brake operating member. A joint securing area is disposed on the hydraulic fluid transmission unit, wherein the joint securing area is structured to couple to the first end of the hydraulic fluid conduit. A rotation restrictor is disposed at the joint securing area, wherein the rotation restrictor is structured to restrict rotation of the first end of the hydraulic fluid conduit relative to the joint securing area.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention is directed to bicycles and, more particularly, to various features of a bicycle brake device.  
           [0002]    Bicycle brake control devices typically are mounted to the handlebar of the bicycle. Such devices often comprise a brake bracket that is mounted to the handlebar and a lever member that is movably mounted to the brake bracket. When the brake apparatus is operated using hydraulic power, the lever member is operatively connected to the brake apparatus via a hydraulic fluid transmission unit that generates hydraulic pressure in accordance with the movement of the lever member and transmits this pressure to the brake apparatus.  
           [0003]    The hydraulic fluid transmission unit typically is integrally formed with the bracket. The hydraulic fluid transmission unit has a tank that stores the hydraulic fluid, a master cylinder, and a piston. The piston is constructed such that one end can come into contact with the lever member. When the lever member is moved toward the handlebar, pressure is exerted on another end of the piston to compress the hydraulic fluid from the tank into the master cylinder.  
           [0004]    A joint securing area for securing a rotatable connecting joint, termed a ‘banjo’, is disposed on the hydraulic fluid transmission unit. The connecting joint serves to fluidly connect the master cylinder to a brake hose, which acts as a hydraulic pipe. The connecting joint typically comprises a cylindrical member, a bolt member that extends through the center of the cylindrical member and screws into the joint securing area, and a hose connector that extends radially outwardly from the outer circumferential surface of the cylindrical member. The outer circumferential surface of the hose connector is adapted to be inserted into the brake hose. A caulking member is fixed to the hose connector with a gap between it and the outer circumferential surface of the cylindrical member in order to caulk and secure the brake hose to the hose connector.  
           [0005]    A fluid pathway is formed in the bolt member such that fluid from the master cylinder travels through the tip of the bolt member and through the center of the bolt member. The fluid pathway opens out to the outer circumferential area of the bolt member at an intermediate location of the bolt member. The inner diameter of the cylindrical member is larger than the outer diameter of the bolt member, so a hydraulic fluid path is formed between the outer peripheral surface of the bolt member and the inner peripheral surface of the cylindrical member. This fluid path communicates the brake fluid to the hose connector and then to the braking apparatus. O-rings are disposed between one side surface of the cylindrical member and the hydraulic fluid transmission unit and between the other side surface of the cylindrical member and the top of the bolt member. When the connecting joint and the brake hose are assembled in this manner, the brake hose generally is oriented at an angle to the hydraulic fluid transmission unit in a manner that it does not become an obstacle even if the handlebar is turned.  
           [0006]    When a connecting joint of the type having a bolt member as described above is mounted to a conventional hydraulic fluid transmission unit, the bolt member is rotated in a clockwise direction, for example, to tighten the bolt and thereby secure the connecting joint to the hydraulic fluid transmission unit. However, as the bolt member becomes tighter with the cylindrical member, the cylindrical member may rotate clockwise together with the bolt member, and the brake hose orientation may deviate from the desired direction. Similarly, when the bolt member is rotated in a counterclockwise direction to remove the connecting joint from the hydraulic fluid transmission unit, the cylindrical member may rotate counterclockwise together with the bolt member until the frictional force between the cylindrical member and the bolt member is sufficiently relieved. This results in the brake hose being pulled. Consequently, attaching and removing the connecting joint from the hydraulic fluid transmission unit becomes difficult and risks damage and/or misalignment of the brake hose.  
         SUMMARY OF THE INVENTION  
         [0007]    The present invention is directed to inventive features of a bicycle brake device. In one embodiment, a brake control device is provided for connecting to a hydraulic fluid conduit, wherein the hydraulic fluid conduit has a first end for connecting to the brake control device and a second end for connecting to a braking apparatus. The brake control device comprises a bracket that can be mounted to a handlebar of the bicycle, a brake operating member that is movably coupled to the bracket, and a hydraulic fluid transmission unit disposed on the bracket. The hydraulic fluid transmission unit is structured to communicate a hydraulic fluid to the hydraulic fluid conduit in response to movement of the brake operating member. A joint securing area is disposed on the hydraulic fluid transmission unit, wherein the joint securing area is structured to couple to the first end of the hydraulic fluid conduit. A rotation restrictor is disposed at the joint securing area, wherein the rotation restrictor is structured to restrict rotation of the first end of the hydraulic fluid conduit relative to the joint securing area. Additional inventive features will become apparent from the description below, and such features may be combined with the above features to provide additional benefits. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    [0008]FIG. 1 is a side view of a front portion of a bicycle including a particular embodiment of a brake control device;  
         [0009]    [0009]FIG. 2 schematic view of a particular embodiment of a brake apparatus used with the bicycle shown in FIG. 1;  
         [0010]    [0010]FIG. 3 is a partial cross-sectional view of a particular embodiment of a brake control device used with the bicycle shown in FIG. 1;  
         [0011]    [0011]FIG. 4 is an exploded perspective view of a particular embodiment of brake hose connecting components used with the brake control device shown in FIG. 3;  
         [0012]    [0012]FIG. 5 is a side cross-sectional view of the brake hose connecting components in an assembled condition;  
         [0013]    [0013]FIG. 6 is a front view of the brake hose connecting components in the assembled condition; and  
         [0014]    [0014]FIG. 7 is an exploded view of an alternative embodiment of brake hose connecting components.  
     
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
       [0015]    [0015]FIG. 1 is a side view of a front portion of a bicycle  10  including a particular embodiment of a braking apparatus. The bicycle  10  is known in the conventional art, and it includes a bicycle frame  14  having a handlebar  15 , front and rear forks  16  (only the front fork having a double crown suspension is shown in the figure), front and rear wheels  17  (only the front wheel is shown in the figure), a drive system including sprockets and a chain (not shown), and front and rear disc brake systems  12  (only the front disc brake system is shown in the figure).  
         [0016]    The front disc brake system  12  includes a brake apparatus  18 , a brake control device  23 , and a brake hose  25 . Brake apparatus  18  comprises a brake caliper  21  that is mounted to the front fork  16 , and a disc rotor  22  that is mounted to the front wheel  17 . Brake control device  23  controls the operation of the brake apparatus  18 , and brake hose  25  hydraulically connects the brake apparatus  18  to the brake control device  23 . A connecting joint  26  that is secured to the brake control device  23  is connected to the upper end of the brake hose  25 .  
         [0017]    The disc rotor  22  is secured to the hub of the front wheel  17 , as shown in FIG. 1, and rotates together with it. The disc rotor  22  is a round plate-shaped member formed from stainless steel alloy, for example. Disc rotor  22  comprises a ring-shaped rotor member  22   b , the outer surfaces of which constitute friction contact surfaces, and a centrally-disposed hub mounting member  22   a , such members being formed as a single unit.  
         [0018]    The brake caliper  21  is mounted to the front fork  16  of the bicycle  10  at a position near the disc rotor  22 , and it can apply constricting force to the disc rotor  22  to stop its rotation. As shown in FIG. 2, the brake caliper  21  includes a housing  70  and a piston unit  71 . The housing  70  comprises a heat-conductive material such as aluminum alloy, and it has a first housing member  72   a  and a second housing member  72   b  that are connected together using a bolt. The two housing members  72   a  and  72   b  have essentially the same configuration. One end of the brake hose  25  is connected to the second housing member  72   b  to supply brake fluid to the housing members  72   a  and  72   b . The piston unit  71  has four pistons  74  (only two are shown in the figure) and a pair of brake pads  76 . The pistons  74  are movably placed in the first housing member  72   a  and the second housing member  72   b , respectively, and move between a brake release position and a braking position. The brake pads  76  are disposed on the ends of the pistons  74  and move integrally therewith. Therefore, when the pistons  74  move from the brake release position to the brake position, the brake pads  76  also move from the brake release position to the braking position. When located at the braking position, the brake pads  76  grasp either side of the disc rotor  22  via friction engagement therewith, thus braking the front wheel  17  via the disc rotor  22 . When located at the brake release position, the brake pads  76  are separated from the disc rotor  22 , thus releasing the disc rotor  22  and permitting it to rotate freely.  
         [0019]    The brake control device  23  is fluidly connected to the brake apparatus  18  via the brake hose  25 . As shown in FIGS. 3 through 6, the brake control device  23  includes a bracket  30  that can be mounted to the handlebar  15 , a manually-operable lever member  31  that is movably disposed on the bracket  30 , a hydraulic fluid transmission unit  24  that can transmit brake fluid to the front disc brake system  12  via the brake hose  25  (through compression of the brake fluid resulting from movement of the lever  31 ), a joint securing area  27  disposed on the hydraulic fluid transmission unit  24  for securing connecting joint  26 , and a rotation restrictor  28  that is formed in close proximity to the joint securing area  27  to restrict the rotation of the connecting joint  26 .  
         [0020]    In this embodiment, the bracket  30  is integrally formed with the hydraulic fluid transmission unit  24 . Bracket  30  has a mounting piece  40  that is mounted to the handlebar  15  and a support member  41  that is integrally formed with the mounting piece  40 . A mounting band  40   a  is placed such that it surrounds the handlebar  15 , and bracket  30  can be mounted to the handlebar  15  by inserting a bolt through the mounting band  40   a  and into mounting piece  40 . A movement shaft  42  is disposed in the support member  41  along an axis that is generally perpendicular to the handlebar  15 . The lever member  31  is rotatably mounted to the movement shaft  42  and protrudes from the bracket  30 . Lever member  31  can move in a direction such that it approaches the handlebar  15  from the brake release position shown in FIG. 3.  
         [0021]    The hydraulic fluid transmission unit  24  has a master cylinder  81 , a piston  82  that moves inside the master cylinder  81  along an axis of operation X to compress the brake fluid, and a fluid tank  83  that stores the brake fluid. The fluid tank  83  and the master cylinder  81  are integrally formed with the bracket  30 . One end of the piston  82  protrudes from the master cylinder  81  toward the left in FIG. 3 such that it comes into contact with a contact piece  44  of the lever member  31 , and force is applied to the piston  82  toward the left in FIG. 3 via a return spring  84 . As a result, force is applied to the lever member  31  in the direction of the brake release position.  
         [0022]    Connecting joint  26  is mounted to the tip of the master cylinder  81  at the joint securing area.  27 . As shown in FIG. 4, the joint securing area  27  comprises a securing surface  27   a  and a screw hole  27   b.  Securing surface  27   a  is formed on one end surface of the master cylinder  81  of the hydraulic fluid transmission unit  24  such that the securing surface  27   a  lies perpendicular to the axis of operation X. Screw hole  27   b  is formed essentially in the center of the securing surface  27   a.    
         [0023]    The connecting joint  26  has a bolt member  51  that is screwed into the screw hole  27   b , a joint main unit  52 , and a caulking member  53  that caulks and secures the brake hose  25  to the joint main unit  52 . O-rings  54  are placed between the top  51   a  of the bolt member  51  and one side surface of the joint main unit  52 , and between the securing surface  27   a  of the master cylinder  81  and the other side surface of the joint main unit  52 , respectively.  
         [0024]    As shown in FIG. 5, a fluid path  51   c  is formed in a shaft  51   b  of bolt member  51 . Fluid path  51   c  extends through the tip of the bolt member  51  and along the center of bolt member  51 . Fluid path  51   c  opens through the outer circumferential surface of bolt member  51  partway though the shaft  51   b  of the bolt member  51 . The opening of the fluid path  51   c  is located in close proximity to the inner circumferential surface of the joint main unit  52 .  
         [0025]    The joint main unit  52  has a cylindrical member  52   a  and a hose connector  52   b . Bolt member  51  passes through the center of cylindrical member  52   a  and secures cylindrical member  52   a  to the joint securing area  27 . The inner diameter of the cylindrical member  52   a  is larger than the outer diameter of the shaft  51   b  of the bolt member  51 , thus forming a cylindrical space  52   d  between the shaft  51   b  of the bolt member  51  and the inner circumferential surface of the cylindrical member  52   a.  The fluid exiting fluid path  51   c  flows into cylindrical space  52   d  and toward hose connector  52   b.    
         [0026]    Hose connector  52   b  extends radially outwardly from the outer circumferential surface of the cylindrical member  52   a  and forms a fluid path  52   c.  A sawtooth area  52   e  that has a sawtooth cross-sectional configuration is formed on the outer circumferential surface of the tip of hose connector  52   b . The brake hose  25  is fitted over this sawtooth area  52   e  so that the sawtooth area locks the brake hose  25  in place. The hose connector  52   b  may be formed integrally with the cylindrical member  52   a  and/or fixed using some other fixing means such as welding or screw attachment. Both side surfaces of the cylindrical member  52   a  are sealed by the O-rings  54 . As a result, a closed fluid channel that extends from the hydraulic fluid transmission unit  24  to the brake hose  25  is formed by the hydraulic fluid path  51   c  in the bolt member  51 , the cylindrical space  52   d  and the hydraulic fluid path  52   c.    
         [0027]    The caulking member  53  is disposed with a gap between the sawtooth area  52   e  of the hose connector  52   b  and the outer circumferential surface of the cylindrical member  52   a.  The caulking member  53  has a round plate-shaped fixed piece  53   a  and a cylindrical caulking piece  53   b . Fixed piece  53   a  is welded or otherwise fixed to the hose connector  52   b . Caulking piece  53   b  extends from the outer circumference of the fixed piece  53   a  and covers the outer circumferential surface of the brake hose  25 . The brake hose  25  is firmly secured and sealed to the hose connector  52   b  by pressing the caulking member  53   b  toward the sawtooth area  52   e , such as by crimping.  
         [0028]    The rotation restrictor  28  comprises a pair of protrusions  29   a  and  29   b  that protrude in the direction of the axis of operation X in close proximity to the securing surface  27   a . Protrusions  29   a  and  29   b  are disposed such that they sandwich the hose connector  52   b  between the outer circumferential surface of cylindrical member  52   a  and the fixed piece  53   a  of the caulking member  53 . This construction restricts the rotation of the connecting joint  26  around the axis of operation X, as shown in FIG. 6. A small gap is formed between the hose connector  52   b  and the pair of protrusions  29   a  and  29   b  so that the connecting joint  26  can rotate only slightly between the protrusions  29   a  and  29   b  when it is being attached or detached.  
         [0029]    The brake control device  23  is assembled as follows. First, the brake hose  25  is connected to the sawtooth area  52   e  of hose connector  52   b  and then caulked and secured by crimping the caulking member  53 . The O-rings  54  are then placed on either side of the cylindrical member  52   a  as shown in FIG. 4, and the hose connector  52   b  is fitted between the protrusions  29   a  and  29   b . The bolt member  51  is passed through the center of cylindrical member  52   a  and screwed into the screw hole  27   b  of the joint securing area  27 . When this is done, the joint main unit  52  is mounted such that the hose connector  52   b  of the connecting joint  26  is sandwiched by the pair of protrusions  29   a  and  29   b . When the bolt member  51  is tightened using a tool such as a screwdriver, thereby exerting a friction force on the joint main unit  52  that tends to rotate the joint main unit  52  clockwise together with the bolt member  51 , the hose connector  52  is prevented from rotating by the left side protrusion  29   a . Consequently, the joint main unit  52  does not rotate together with the bolt member  51 . Also, the direction of connection of the brake hose  25  does not deviate from the preset direction, thus making it easy to connect the brake hose  25 . The connecting joint  26  may be further secured to the joint securing area  27  by tightening the bolt member  51  to the point at which appropriate pressure is exerted on the O-rings  54 , and the fluid channel described above is formed.  
         [0030]    After the bolt member  51  has been screwed in, the protrusion  29   b  also acts as a rotation stopper when the brake hose  25  or the caulking member  53  is subjected to an external force that tends to rotate the joint main unit  52  in the counterclockwise direction. Protrusion  29   b  thus functions to prevent the loosening of the bolt member  51 .  
         [0031]    To detach the brake hose  25 , the bolt member  51  should be loosened. Normally, the joint main unit  52  has a tendency to rotate counterclockwise together with the bolt member  51  because of the friction between joint main unit  52  and bolt member  51  in the tightened condition. However, in this case such counterclockwise rotation of the hose connector  52   b  is restricted by the right protrusion  29   b , so the joint main unit  52  does not rotate together with the bolt member  51 . Consequently, the brake hose  25  can be easily detached as well. In any event, because the securing surface  27   a  of the connecting joint  26  is perpendicular to the axis of operation X of the master cylinder  81 , the joint securing area  27  can be aligned with the axis of operation X, thus making the construction of the joint securing area  27  simple.  
         [0032]    While the above is a description of various embodiments of inventive features, further modifications may be employed without departing from the spirit and scope of the present invention. For example, in the above embodiment, the securing surface  27   a  of the joint securing area  27  was perpendicular to the axis of operation X, but a securing surface  127   a  of a joint securing area  127  may be parallel to the axis of operation X, as shown in FIG. 7. The securing surface  127   a  is formed on the outer circumferential surface of the master cylinder  81  in a protruding fashion, and a screw hole  127   b  is formed in the securing surface  127   a . A rotation restrictor  128  comprises a pair of protrusions  129   a  and  129   b . The protrusions  129   a  and  129   b  may be formed on the right side of the securing surface, typically with a vertical gap therebetween. The remainder of the construction is identical to that of the previous embodiment, so a detailed explanation thereof will be omitted. Because the connecting joint is disposed perpendicular to the axis of operation X in this embodiment, the brake control device  23  can be made shorter in length along the axis of operation X when the connecting joint  26  is attached thereto.  
         [0033]    In the above embodiments, the rotation restrictor comprised one or more protrusions, but one or more protrusions may be formed on the connecting joint (e.g., pointing outwardly from an area of the outer scaling surface of the cylindrical member  52   a  of the joint main unit  52  toward the securing surface  27   a ), and one or more concavities formed in the securing surface  27   a.    
         [0034]    In the above embodiments, the rotation restrictor  28  was formed integrally with the master cylinder  81 , but it can constitute one or more separate components. It is also possible to select the direction in which the brake hose  25  is removed by allowing the connecting joint  26  to be positioned at multiple positions along the direction of rotation.  
         [0035]    The size, shape, location or orientation of the various components may be changed as desired. Components that are shown directly connected or contacting each other may have intermediate structures disposed between them. The functions of one element may be performed by two, and vice versa. The structures and functions of one embodiment may be adopted in another embodiment. It is not necessary for all advantages to be present in a particular embodiment at the same time. Every feature which is unique from the prior art, alone or in combination with other features, also should be considered a separate description of further inventions by the applicant, including the structural and/or functional concepts embodied by such feature(s). Thus, the scope of the invention should not be limited by the specific structures disclosed or the apparent initial focus on a particular structure or feature.