Abstract:
A bicycle having at least two wheels, a frame supported on the two wheels, a brake, a gear shift mechanism (e.g., a chain derailleur), a shifter (e.g., a shift lever), and a brake mechanism coupled to the brake and also coupled to the gear mechanism (e.g., via an auxiliary shift cable between a brake lever and a shift lever). Preferably, the shifter and brake mechanism are mounted on a handlebar assembly (e.g., the shifter mounted on an extension and the brake mechanism mounted on a base bar). In one embodiment, the brake mechanism comprises a brake support fixedly secured to the handlebar assembly, a lever base pivotally mounted to the brake support for rotation about a first axis, and a brake lever pivotally mounted to the lever base for rotation about a second axis. Preferably, the lever base is rotationally biased relative to the brake support.

Description:
BACKGROUND 
       [0001]    The present invention relates generally to bicycles, and more specifically to mechanisms for shifting gears on bicycles. 
         [0002]    Bicycles are commonly driven by a chain that connects a front sprocket connected to the pedal to a rear sprocket connected to the rear wheel. Many bicycles have multiple sprockets on the front or rear in order to provide the ability to select different gear ratios between the front and rear sprockets. On such bicycles, changing gears involves moving the chain from one sprocket to another sprocket using a derailleur. The derailleur is commonly controlled by a shift lever mounted on the handlebars and connected to the derailleur by a shift cable. 
         [0003]    Some bicycles have handlebars that provide multiple locations for a user to grab. For example, one type of bicycle is a time trial bicycle that commonly includes at least two different locations for placing a user&#39;s hands. In a first location, the hands are widely spaced, and in a second location, the hands are narrowly spaced and positioned further forward. The first position is commonly used when the rider desires better steering control or wants to stand up to provide more power to the pedals, and the second position is commonly used when the rider desires a more aerodynamic riding position. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention provides a bicycle that facilitates actuation of the gear shift mechanism from multiple locations. Specifically, the bicycle includes at least two wheels, a frame supported on the two wheels, a brake, a gear shift mechanism (e.g., a chain derailleur), a shifter (e.g., a shift lever) for changing a gear ratio of the gear shift mechanism, and a brake mechanism coupled to the brake and also coupled to the gear mechanism (e.g., via an auxiliary shift cable between a brake lever and a shift lever). Preferably, the shifter and brake mechanism are mounted on a handlebar assembly (e.g., the shifter mounted on an extension and the brake mechanism mounted on a base bar). 
         [0005]    In one embodiment, the brake mechanism comprises a brake support fixedly secured to the handlebar assembly, a lever base pivotally mounted to the brake support for rotation about a first axis (e.g., a base axis), and a brake lever pivotally mounted to the lever base for rotation about a second axis (e.g., a lever axis). As a result of this arrangement, the brake lever is effectively movable in at least two different planes. Preferably, movement of the brake lever in one of the at least two different planes actuates the brake, and movement of the brake lever in the other of the at least two different planes actuates the gear mechanism. 
         [0006]    Preferably, the lever base is rotationally biased relative to the brake support. The brake mechanism can further comprise an auxiliary shift cable secured to the lever base such that rotation of the lever base causes movement of the auxiliary shift cable. A brake cable is preferably positioned through both the brake support and the lever base and secured to the brake lever such that movement of the brake lever causes movement of the brake cable. 
         [0007]    Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a side view of a bicycle embodying the present invention. 
           [0009]      FIG. 2  is an enlarged front perspective view of a handlebar assembly from the bicycle illustrated in  FIG. 1 . 
           [0010]      FIG. 3  is a right-side perspective view of a brake mechanism from the bicycle of  FIG. 1 . 
           [0011]      FIG. 4  is a left-side exploded perspective view of the brake mechanism of  FIG. 3 . 
           [0012]      FIG. 5  is perspective view of portions of the handlebar assembly of  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. 
         [0014]      FIG. 1  illustrates a bicycle  20  including a main frame  22 , a front fork  26  rotationally supported by the main frame  22 , and a seat  28  supported by the main frame  22 . Front and rear derailleurs  30 , 32  facilitate the shifting of gears on the bicycle  20 . The main frame  22  and fork  26  are supported by a rear wheel  34  and a front wheel  36 . A brake  37  can be used to control the speed of the bicycle  20 . A handlebar assembly  38  is coupled to the front fork  26 , as described in more detail below. 
         [0015]    The illustrated handlebar assembly  38  includes a handlebar stem  40  coupled to the front fork  26 , and a base bar  42  secured to the handlebar stem  40 . The illustrated base bar  42  is clamped to the handlebar stem  40 , but could instead be integrally formed with the handlebar stem  40 . The base bar  42  (commonly called a bull horn bar) includes two wide-grip locations  44  (commonly called the “drops”) for the user to engage when riding the bicycle. The drops  44  are commonly used when the rider is accelerating quickly or climbing a hill. 
         [0016]    Handlebar extensions  46  are secured to the base bar  42 . The illustrated extensions  46  are bolted to the base bar  42 , but could instead be integrally formed with the base bar  42 . The extensions  46  include two narrow-grip locations  48  for the user to engage when riding. The narrow-grip locations  48  are typically engaged in order to achieve an aerodynamic riding position. In this position, the rider&#39;s forearms rest on arm supports  50 , as is known in the art. 
         [0017]    Each extension  46  includes a main shifter  52 , 54  that shifts one of the two derailleurs  30 , 32 . In the illustrated embodiment, the right shifter  52  shifts the rear derailleur  30 , and the left shifter  54  shifts the front derailleur  32 . Each main shifter  52 , 54  operates substantially the same, and therefore only the right main shifter  52  will be described in detail. 
         [0018]    The right main shifter  52  includes a shifter base  56  positioned partially in the end of the corresponding extension  46 , and a shift lever  48  pivotally attached to the shifter base  56 . A main shift cable (not shown) couples the shift lever  48  to the rear derailleur, as is known in the art. The shift lever  58  is a ratchet-type lever that will return to a neutral position (shown in  FIG. 2 ) after shifting. For example, if the illustrated right shift lever  58  is moved downward from the illustrated neutral position (broken lines in  FIG. 5 ), the rear derailleur  32  will upshift and, when the right shift lever  58  is released, it will return to the neutral position (shown in  FIG. 2  and solid lines in  FIG. 5 ). Similarly, if the illustrated right shift lever  58  is moved upward, the rear derailleur  32  will downshift and, when the right shift lever  58  is released, it will return to the neutral position. The left shifter  54  is designed to shift the front derailleur  30  in a similar manner. This basic design for a ratcheting shift lever is known in the art and will not be described further in this document. 
         [0019]    A brake mechanism  60 , 62  is secured to each end of the base bar  42 . Each brake mechanism  60 , 62  includes a brake lever  64  pivotally mounted on a lever base  66  for rotation about a lever axis. The brake lever  64  can be engaged by a user to move a brake cable  68  to operate a bicycle brake, as is known in the art. The left brake mechanism  62  operates the front brake  37 , and the right brake mechanism  60  operates a rear brake (not shown). The illustrated brake cables  68  are threaded through the base bars  42 . 
         [0020]    The right brake mechanism  60  is shown in more detail in  FIGS. 3 and 4  and further includes a brake support  70  secured to the end of the base bar  42  by wedges  72  and an anchor screw  74 . More specifically, the brake support  70  includes a frustoconical surface  76  that engages one end of the wedges  72 , and the anchor screw  74  also includes a frustoconical surface  78  that engages the other end of the wedges  72 . By threading the anchor screw  74  into the brake support  70 , the wedges  72  are forced radially outward into engagement with the interior of the base bar  42  to thereby secure the brake support  70  to the base bar  42 . A threaded end  80  ( FIG. 3 ) of the anchor screw  74  includes a hexagonal socket  82  that is adapted to be engaged by a hex key tool (not shown) inserted through the brake support  70  to facilitate tightening the anchor bolt  74 . 
         [0021]    A brake stud  84  is threaded into the brake support  70  and provides a fixed structure for mounting the lever base  66 . The lever base  66  is mounted for lateral rotation on the brake stud  84  about a base axis, and is secured in place by a mounting screw  86 . The lever base  66  can be rotated inward about the base axis from a neutral position relative to the brake support  70 . A torsion spring  88  is positioned between the brake support  70  and the lever base  66  to rotationally bias the lever base  66  back to the neutral position. 
         [0022]    The brake support  70  includes a first housing stop  90  including a hole  92  ( FIG. 3 ) for receiving an auxiliary shift cable  93  ( FIG. 5 ), and a cylindrical recess  94  ( FIG. 4 ) for receiving the end of an auxiliary shift housing  96  ( FIG. 5 ). The lever base  66  includes a cable groove  98  positioned circumferentially around the lever base  66 , and a cable anchor  100  for securing the end of the auxiliary shift cable  93  to the lever base  66 . The auxiliary shift cable  93  is secured to the cable anchor  100  (e.g., by a clamp) and extends around the lever base  66  in the cable groove  98 . The auxiliary shift cable  93  then passes through the hole  92  and into the auxiliary shift housing  96 . 
         [0023]    The other end of the auxiliary shift housing  96  is positioned in a second housing stop  102  near the right shifter  52 . The second housing stop includes a hole  104  for receiving the auxiliary shift cable  93 , and a cylindrical recess (not visible) for receiving the other end of an auxiliary shift housing  96 . The auxiliary shift cable  93  passes through the second housing stop  102  and wraps around a lower side of the right shift lever  58 . The end of the auxiliary shift cable  93  is secured to the right shift lever  58  such that upward movement of the shift lever  58  will pull the auxiliary shift cable  92 . 
         [0024]    In operation, the right shifter  52  can be used at any time to shift the rear derailleur  32  in both upshift and downshift directions by moving the right shift lever  58  downward and upward, respectively. After a shift, the shift lever  58  will return to its neutral position due to a biasing mechanism (not shown). 
         [0025]    The brake lever  64  can be rotated inward (i.e., toward the centerline of the bicycle  20 , and shown in broken lines in  FIG. 5 ) to cause the auxiliary shift cable  93  to be pulled, which forces the main shift lever  58  to rotate downward (shown in broken lines in  FIG. 5 ), resulting in upshifting of the rear derailleur  32 . After the brake lever  64  is released, it will return to its neutral position due to the torsion spring  88 , and the shift lever  58  will return to its neutral position, as described above. Accordingly, it can be seen that the illustrated brake lever  64  can act as an auxiliary shift lever to cause upshifting of the corresponding derailleur. This is particularly useful when the rider is grasping the base bar  42  (e.g., when standing on the pedals), thus eliminating the need for the rider to change hand positions in order to upshift. 
         [0026]    The illustrated embodiment is shown with an auxiliary shift cable that facilitates upshifting of the rear derailleur using the brake lever. If desired, an additional auxiliary shift cable could be added in order to facilitate downshifting of the rear derailleur. This would be done by attaching this additional auxiliary shift cable such that outward rotation of the brake lever pulls the additional auxiliary shift cable and results in upward rotation of the corresponding main shift lever. Alternatively, a two-way actuating member (e.g., a mechanical linkage or a two-way cable actuator) could be used to achieve both upshifting and downshifting capabilities using a single actuator. 
         [0027]    In addition, while not shown in the illustrated embodiment, it should be understood that the left brake mechanism could be designed to act as an auxiliary shift lever for actuating the left shifter. Such a design would facilitate shifting of the front derailleur using either the left shifter or the brake lever of the left brake mechanism. 
         [0028]    Various features and advantages of the invention are set forth in the following claims.