Patent Publication Number: US-2011048873-A1

Title: Structure of hydraulic brake lever assembly

Description:
(a) TECHNICAL FIELD OF THE INVENTION 
     The present invention generally relates to a structure of hydraulic brake lever assembly that is formed in an inside-accommodated configuration to eliminate invasion of air for ensuring better protection. 
     (b) DESCRIPTION OF THE PRIOR ART 
     Taiwan Patent No. 1294388 issued in Mar. 11, 2008 discloses a brake lever and an adjustment device thereof wherein a mount  10  is coupled internally a hydraulic control set  30 . A fluid tank  11  extends above the mount and the fluid tank  11  comprises a fluid inlet opening  12  communicating an interior space of the mount  10 , whereby the hydraulic control set  30  controls the brake operation realized through the fluid inlet opening. 
     The hydraulic tank  11  is structured to directly extend from the mount  10  and is covered by a lid that is secured by bolts, so that the hydraulic tank is exposed above the mount  10  and is thus susceptible to invasion of air that forms air bubbles that might deteriorates the brake operation and thus threatens riding safety. Further, hole drilling must be carried out first and then bolt securing can be done. This makes the assembling inconvenient for the parts are not allowed to individually remove. Thus, when any of the parts is broken, the whole assembly must be replaced. This increases the costs of maintenance. 
     Thus, the present invention aims to solve the problems of the conventional devices of being susceptible to invasion of air that leads to deterioration of brake operation and having high costs of assembling, repairing and maintenance. 
     SUMMARY OF THE INVENTION 
     An objective of the present invention is to provide an inside accommodated construction of hydraulic brake lever assembly that arranges a hydraulic pump inside a lever mount to eliminate invasion of air so as to ensure preciseness and reliability of brake operation for improved safety. 
     Another objective of the present invention is to provide a hydraulic brake lever assembly that is formed by simple and direct assembling a mass-produced hydraulic so as to realize efficient assembling and to allow simple replacement of a broken part without the need of replacing the whole assembly, in case of malfunctioning, whereby maintenance costs of the hydraulic brake lever assembly is effectively reduced. 
     A further objective of the present invention is to provide a hydraulic brake lever assembly that allows for easy inspection of internal hydraulic fluid through an external window and also allows for colorful combinations of a lever mount and a hydraulic pump that are made of different colors so as to enhance visual aesthetics. 
     To achieve the above objectives, the present invention provides a lever mount comprising a barrel-like body forming a bore having a reduced end opening and an opposite end opening from sides of which a pivot joint section for pivotally jointing a brake lever and a clamp ring for mounting to a handlebar project. The lever mount forms in opposite sides thereof window openings in communication with the bore. A master hydraulic pump is accommodated in the bore of the lever mount and comprises an outer cylinder member, an inner bore member, and a piston. The outer cylinder member forms a channel having an end section forming an internal thread. The inner bore member has an external thread section set in engagement with the outer cylinder member and partially projects beyond the reduced end opening to engage an internally threaded fastener member, whereby a hydraulic fluid chamber is defined between the outer cylinder member and the inner bore member. An in-flow passage is defined in a wall of the inner bore member communicating between the hydraulic fluid chamber and a bore defined in the inner bore member. The outer cylinder member forms a fluid charge opening in a wall thereof for communication with the hydraulic fluid chamber and removably closed by a lid and further defines one or two opposite internally-threaded holes at locations circumferentially shifted away from the fluid charge opening and in communication with the hydraulic fluid chamber for receiving, in threading engagement a transparent plug for visual inspection of the fluid contained inside the hydraulic fluid chamber. The inner bore member receives therein a piston that is coupled to a resilient element. The piston has a circumferential surface to which two sealing rings are mounted in a spaced manner. The piston has an outer end forming a socket for receiving and forming a driving coupling with an end of a driving bar that is retained in position by a retention plate. An opposite end of the driving bar is rotatably coupled to a brake lever by means of a rotatable connection sub-assembly. 
     The foregoing objectives and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts. 
     Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded view of a hydraulic brake lever assembly in accordance with the present invention. 
         FIG. 2  is a perspective view of the hydraulic brake lever assembly of the present invention in an assembled form. 
         FIG. 3  is a cross-sectional view of the hydraulic brake lever assembly of the present invention, showing the hydraulic brake lever assembly in a non-actuated condition. 
         FIG. 4  is also a cross-sectional view of the hydraulic brake lever assembly of the present invention in an actuated condition. 
         FIG. 5  is an enlarged cross-sectional view of a portion of the hydraulic brake lever assembly of the present invention taken along a different section. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following descriptions are exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims. 
     As shown in  FIGS. 1-3 , a hydraulic brake lever assembly according to an embodiment of the present invention is composed of a lever mount  10 , a master hydraulic pump  20 , and a brake lever  30 . 
     The lever mount  10  comprises a barrel-like body through which a bore is formed. The bore has a reduced opening  11  defined in an end of the body and an opposite opening defined an opposite end of the body. A pivot joint section  12  extends sideways from one side of the opposite end opening for pivotally jointing the brake lever  30  and a clamp ring  13 , to which a fastener pin  131  is fit, extends sideways from an opposite side of said opposite end opening for mounting to a handlebar of for example a bicycle. Window openings  14  of a proper width are respectively defined in opposite sides of a middle section of the body and in communication with the bore. 
     The master hydraulic pump  20  is arranged inside the barrel-like body of the lever mount  10  and comprises an outer cylinder member  21 , an inner bore member  22 , and a rod-like piston  23 . The outer cylinder member  21  comprises a cylindrical body forming an internal channel that has an end section forming an internal thread  211  for threading engagement with an external thread section  221  of the inner bore member  22  received in the channel of the outer cylinder member  21  so that an end portion of the external thread section  221  of the inner bore member  22  projects beyond the reduced opening  11  of the lever mount  10  for engagement with an inner-threaded fastener member  111  and thus being fixed for the purposes of connection with a hydraulic conduit (not shown). A hydraulic fluid chamber  25  is formed between the outer cylinder member  21  and the inner bore member  22 . The hydraulic fluid chamber  25  is in communication with a fluid in-flow opening  26  defined in the inner bore member  22  for further communication with a bore defined in the inner bore member  22 . The outer cylinder member  21  has a circumferential wall forming a fluid charge opening  27 , which communicates the hydraulic fluid chamber  25  and receives a lid  28  mounted thereto by means of for example bolt for shielding and closing. An inner flange  222  is formed in the bore of the inner bore member  22  to support the piston  23  that is coupled to a resilient element  231 . The piston  23  has an outer circumferential surface to which two sealing rings  232  are mounted in a spaced manner for engagement with an inside surface of the bore of the inner bore member  22  in a fluid sealed manner. The piston  23  has an outer end forming a socket  233 . Also referring to  FIG. 5 , one or two internally-threaded holes  212  are defined through the circumferential wall of the outer cylinder member  21  at locations corresponding to the window openings  14  on the opposite sides of lever mount  10  and circumferentially shifted away from the fluid charge opening  27  to communicate the hydraulic fluid chamber  25 . Transparent plugs  24  are mounted in the holes  212  with threading engagement. This arrangement provides windows for convenient inspection of fluid level inside the hydraulic fluid chamber  25  of the master hydraulic pump  20  and also provides, under the condition that the window openings  14  have a sufficient width, a colorful combination of the lever mount  10  and the master hydraulic pump  20  that are made with different colors to thereby enhance visual aesthetics. 
     The brake lever  30  comprises a handgrip portion and an end that is opposite to the handgrip portion and forms a pivot hole  31  that receives a pivot pin  121  therein for pivotally jointing to the pivot joint section  12  of the lever mount  10 . Two lugs  32  extend sideways from a side of the pivot hole  31  and define aligned holes for rotatably receiving a rotatable connection sub-assembly  34  that is mounted to an outer end of a driving bar  33 . The driving bar  33  has an opposite end forming a sphere  331  that is received and retained in the socket  233  of the piston  23  by a retention plate  224  so as to allow the brake lever  30  to drive the driving bar  33  to cause movement of the piston  23  inside the inner bore member  22  for selectively opening/closing the fluid in-flow opening  26 , as shown in  FIGS. 3 and 4 , to effect brake operation. 
     As shown in  FIG. 3 , the present invention arranges the master hydraulic pump  20  inside the barrel-like body of the lever mount  10  to be secured by a fastener member  111 . The two transparent plugs  24  on opposite sides are arranged to expose through the window openings  14  on the opposite sides of the lever mount  10 . The fluid charge opening  27  and the lid  28  are completely shielded by the lever mount  10  and concealed therein. The driving bar  33  that is pivotally coupled to the brake lever  30  extends into the  22  of the master hydraulic pump  20  with the spherical end  331  thereof positioned against the socket  233  of the piston  23 . The spherical end  331  of the driving bar  33  is set and retained in position by the retention plate  224  set in the end opening of the inner bore member  22 . As such, a hydraulic brake lever assembly is formed in an efficient manner. The lever mount  10  forms an interior hollow space that is sufficient to completely accommodate the master hydraulic pump  20  to provide an inside accommodated assembly, whereby the hydraulic fluid chamber  25 , the fluid charge opening  27 , and the lid  28  are completely concealed inside the lever mount  10 . Air invasion due to exposure of the hydraulic fluid chamber  25  is eliminated, preciseness and reliability of brake operation can be ensured, and driving/riding safety can be improved. When the hydraulic brake lever assembly is broken, repairing can be done by simply replacing only the broken parts, such as brake lever  30  and the master hydraulic pump  2 . Further, depending whether a broken portion occurs in the outer cylinder member  21  or the inner bore member  22 , a malfunctioning master hydraulic pump  20  can be repaired without replacement by a new one. This effectively reduces the costs for maintenance. 
     While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.