Abstract:
The present invention improves the operability of a throttle lever device mounted in the vicinity of a grip at one end of a handlebar of a water jet bike or a snowmobile when the rider rotates the handlebar to the left or right. A front end portion of an operation lever  3  can be moved vertically relative to a bracket  1  for a throttle lever within a certain range, and a throttle cable  6  can be directly or indirectly actuated by virtue of gripping operations of the operation lever  3.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a throttle lever device for increasing and/or decreasing the output of an engine via a throttle cable attached to a handlebar of a water jet bike or a snowmobile in the vicinity of a grip thereof.  
           [0003]    2. Description of the Prior Art  
           [0004]    As shown in FIG. 13, in a conventional throttle lever of this type, a throttle cable  6  is provided for connecting an operation lever  3  and a throttle valve (not shown) of a carburetor. This throttle lever device is fixedly attached to a right-hand side of a handlebar  7  in the vicinity of a grip  8  attached to an end of the handlebar, when viewed from an operator in a travelling direction, via a synthetic resin bracket  1  and a holder  2 , which are attached to the handlebar  7  in such a manner as to hold it therebetween and are fixedly clamped together with an attachment bolt  5 . A support shaft  4  is put through the bracket  1  vertically, so that the operation lever  3  is rotatably supported thereon at a rear end portion thereof. The throttle cable  6  is connected to a front end portion of the operation lever  3  at a drum-like member  6   a  affixed to a tip thereof. In this construction, the operation lever  3  is rotated about the support shaft  4  when it is grasped with the fingers, whereby the throttle cable  6  is in turn pulled to thereby open the throttle valve.  
           [0005]    The aforesaid water jet bike or snowmobile is turned to the left or right when the handlebar  7  is so turned. When turning the handlebar in such a way, as shown in FIG. 14, the position of the fingers of the rider changes vertically relative to the operation lever  3  due to the fact that the handlebar  7  is turned at a certain angle relative to the vehicle body and that the arm of the rider is flexed and/or extended during such operations.  
           [0006]    In other words, when turning to the left, as shown on the rightmost side of FIG. 14, since the arm is extended, the wrist being flexed slightly upwardly, the tips of the fingers tend to move upwardly when compared with the position of the fingers assumed when riding straight as shown at the center of the drawing. On the contrary, when turning to the right, as shown on the leftmost side of the drawing, since the arm is flexed, the wrist being extended slightly downwardly, the tips of the fingers tend to move downwardly when compared with the position thereof assumed when riding straight as shown at the center of the drawing. When these happen, with the conventional throttle lever device, since it is allowed to rotate in horizontal directions but is not in vertical directions, the operation lever  3  cannot follow the movements of the fingers of the rider, leading to a drawback that the operability is deteriorated.  
         SUMMARY OF THE INVENTION  
         [0007]    The present invention improves the operability of a water jet bike or a snowmobile by constructing an operation lever  3  of a throttle lever device such that it oscillates relative to a throttle lever bracket in vertical directions at a front end portion thereof, so that the operation lever  3  can follow the movements of the fingers of the rider when he or she operates and turns a handlebar  7 .  
           [0008]    In other words, a first aspect according to the present invention provides a throttle lever device wherein an operation lever  3  is allowed to move vertically relative to a throttle lever bracket  1  within a certain range at a front end portion thereof, and wherein a throttle cable  6  is operated directly or indirectly through gripping operations of the operation lever  3 .  
           [0009]    A second aspect according to the present invention provides a throttle lever device, wherein a bracket  1  for a throttle lever is provided adjacent to an inside of a grip  8  provided at an end of a handlebar  7 , wherein a support shaft  4  is provided and extended in a vertical direction at a front portion of the bracket  1 , so that an opening of a driving arm  11  is rotatably supported thereon, which driving arm has a substantially U-shaped cross-section and with a front end internal surface of which a drum-like member  6   a  of a throttle cable  6  is brought into engagement, wherein a shaft  11   a  is provided and extended in a horizontal direction at an inner rearward portion of the U-shaped driving arm  11 , so that the operation lever  3  is rotatably supported on the shaft at a rear end portion thereof, and wherein the operation lever  3  is constructed such that it oscillates in vertical directions at a front end thereof.  
           [0010]    A third aspect according to the present invention provides a throttle lever device as set forth in the second invention, wherein a moderating mechanism is provided between the operation arm  3  and an internal surface of the driving arm  11 .  
           [0011]    A fourth aspect according to the present invention provides a throttle lever device, wherein a bracket  1  for a throttle lever is provided adjacent to an inside of a grip  8  provided at an end of a handlebar  7 , which bracket has a hollow support portion  1   d  having upper and lower curved surfaces  1   b  at a front portion thereof, which support portion has a transversely elongated rectangular hole-like opening  1   c  formed in a front portion thereof and a longitudinally elongated hole  1   a  formed in the upper and lower curved surfaces, wherein an operator  22  having a barrel-type external surface is disposed inside the support portion  1   d,  and a support shaft is fixed to an axial center of the operator  22  with ends of the shaft  4  being allowed to protrude outwardly from the upper and lower elongated holes  1   a,  wherein an arm portion  21   c  of a cable driving arm  21  is provided in such a manner as to protrude forwardly from the opening  1   c  with a drum-like member  6   a  of a throttle cable  6  being locked to a distal end of the cable driving arm  21 , which cable driving arm  21  has formed at a rear end thereof a pipe-like base portion  21   a  adapted to rotate on an outer circumferential surface of the barrel-type operator  22  inside the support portion  1   d,  wherein an inwardly formed opening of the operation lever  3  having a U-shaped cross-section is rotatably supported at both end portions of the support shaft  4  in such a manner as to cover the cable driving arm  21 , and wherein an arc-like projection  3   c  is provided at a front inner end portion of the operation lever  3  for abutment with a distal inner end portion of the cable driving arm  21 .  
           [0012]    The present disclosure relates to subject matter contained in Japanese Patent Application No. Hei. 10-282161, filed on Oct. 5, 1999, and which is expressly incorporated herein by reference in its entirety. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 is a plan view showing a first embodiment of the present invention;  
         [0014]    [0014]FIG. 2 is a right-hand side view of FIG. 1;  
         [0015]    [0015]FIG. 3 is a sectional view taken along the line B-B of FIG. 2;  
         [0016]    [0016]FIG. 4 is a sectional view taken along the line A-A of FIG. 1;  
         [0017]    [0017]FIG. 5 is a partially cutaway plan view showing a second embodiment of the present invention;  
         [0018]    [0018]FIG. 6 is a right-hand side view of FIG. 5;  
         [0019]    [0019]FIG. 7 is a sectional view taken along the line D-D of FIG. 6;  
         [0020]    [0020]FIG. 8 is a sectional view taken along the line C-C of FIG. 5;  
         [0021]    [0021]FIG. 9 is a sectional view corresponding to FIG. 8, showing a state in which an operation lever is rotated upwardly;  
         [0022]    [0022]FIG. 10 is a perspective view, partially cutaway, showing a relationship of a cable driving arm, an operator and a support shaft;  
         [0023]    [0023]FIG. 11 is a perspective view, partially cutaway, showing a relationship of the cable driving arm, the support shaft, the operation lever and a bracket;  
         [0024]    [0024]FIG. 12 is a diagram showing a relationship between the operation lever of the throttle lever device of the present invention and the movements of the fingers and arm of a rider;  
         [0025]    [0025]FIG. 13 is a partially cutaway plan view of a conventional throttle lever device; and  
         [0026]    [0026]FIG. 14 is a diagram showing a relationship between an operation lever of the conventional throttle lever device and the movements of the fingers and arm of a rider.  
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0027]    First Embodiment:  
         [0028]    In FIG. 1, reference numeral  1  denotes a bracket for a throttle lever provided adjacent to an inside of a grip  8  provided at an end of a handlebar  7  of a water jet bike or a snowmobile. This bracket  1  is made of a synthetic resin as with a conventional bracket and is combined with a holder  2  which is assembled to the handlebar  7  from the rear such that the bracket  1  and the holder  2  hold the handlebar  7  therebetween, and they are clamped together with an attachment bolt  5  for fixation together to the handlebar  7 .  
         [0029]    As shown in FIGS. 3 and 4, a support shaft  4  is provided at a front portion of the bracket  1  in a vertical direction, and openings of a driving arm  11 , made from a synthetic resin and having a U-shaped cross-section, are rotatably supported on the support shaft  4 , and a screw  9  is screwed into a lower end of the support shaft  4  from below so as to prevent the support shaft  4  from coming off the bracket  1 .  
         [0030]    Formed on a front inside portion of the driving arm  11 , as shown in FIG. 3, is an engagement portion  11   b  for engagement with a drum member  6   a  disposed at a tip of a throttle cable  6 , and a plurality of moderating grooves  11   d  (for instance, five grooves) are formed on the right-hand side of the engagement portion  11   d  at predetermined intervals, as shown in FIG. 4.  
         [0031]    In addition, a shaft  11   a  is provided at an inwardly rear portion of the driving arm  11  in such a manner as to face outwardly, and the synthetic resin operation lever  3  is rotatably supported on the shaft  11   a  at a rear end portion thereof.  
         [0032]    A spring hole  3   b  is formed in a front end of the operation lever  3 , while a horizontal shaft hole  3   a  is formed in a rear portion thereof, and as shown in FIGS. 3 and 4, a moderating ball  15  is loaded in the spring hole  3   b  in such a state in which the ball is biassed outwardly. The ball  15  is then brought into elastic engagement with one of the moderating grooves  11   d  formed in the internal surface of the driving arm  11 , and in this state, the shaft  11   a  is inserted into the shaft hole  3   a,  and when a screw  13  is screwed thereinto and tightened via a collar  12 , the operation lever  3  is rotatably supported on the shaft  11   a.    
         [0033]    Reference numeral  6  denotes a throttle cable, which is identical with a conventional throttle cable. The throttle cable  6  is inserted from a left-hand side of the bracket, and the drum member  6   a  at the tip of the cable  6  is in engagement with the engagement portion  11   b  on the inside at the front end portion of the driving arm  11 .  
         [0034]    Next, an operation of the throttle lever device according to the first embodiment of the present invention will be described.  
         [0035]    With the fingers being placed on the operation lever  3  while the grip  8  being grasped by the hand of the rider, when the operation lever  3  is pulled toward the rider (rearward), as shown in double-dashed lines, the operation lever  3  and the driving arm  11  rotate together about the support shaft  4 , and the throttle cable  6  is in turn pulled. Since this opens a throttle valve (not shown) of a carburetor of an engine, the density of fuel that is supplied to the engine is increased, whereby the engine speed is in turn increased.  
         [0036]    When the rider turns the handlebar  7  to the left or right in the above state, as shown in FIG. 12, the position of the fingers of the rider changes vertically relative to the operation lever  3 . With the throttle lever device according to the present invention, however, since the operation lever  3  is rotatably supported on the shaft  11   a  of the driving arm  11 , as shown in FIGS. 2 and 12, the throttle lever is allowed to rotate vertically within a range from (a) to (b), whereby the throttle lever can follow the movements of the fingers of the rider, good operability being thereby obtained.  
         [0037]    In addition, a moderating mechanism is formed such that the moderating ball  15  is brought into engagement with one of the moderating grooves  11   d  formed in the driving arm by virtue of the elastic force of the spring  14 , so that the operation lever  3  can rotate vertically with a certain moderating feeling (five moderating steps being provided in this embodiment).  
         [0038]    Second Embodiment:  
         [0039]    In FIG. 5, reference numeral  1  denotes, as with the first embodiment, a bracket for a throttle lever provided adjacent to a grip  8  provided at an end of a handlebar  7  of a water jet bike or a snowmobile. This bracket  1  is formed of a synthetic resin and is combined with a holder  2  which is assembled to the handlebar  7  from the rear such that the bracket  1  and the holder  2  hold the handlebar  7  therebetween, and they are clamped together with an attachment bolt  5  for fixation together to the handlebar  7 .  
         [0040]    As shown in FIGS. 8 and 11, a hollow support portion  1   d  is formed at a front portion of the bracket  1 , which support portion has upper and lower curved surfaces  1   b,  and a transversely elongated rectangular hole-like opening  1   c  is formed in a front portion of the support portion  1   d,  a longitudinally elongated hole (refer to FIG. 5) being formed in the upper and lower curved surfaces, respectively.  
         [0041]    As shown in FIGS. 8 and 10, an operator  22  having a barrel-type external surface is disposed in the support portion  1   d,  and a support shaft  4  is fixed to an axial center of the operator  22 , both end portions of the support shaft  4  being allowed to protrude outwardly from the upper and lower elongated holes  1   a.    
         [0042]    Reference numeral  21  denotes a cable driving arm, and as shown in FIGS.  7  to  10 , this cable driving arm comprises a pipe-like base portion  21 , an arm portion  21   c  radially protruding from the pipe-like base portion and an attachment portion  21   b  provided at a distal end of the arm portion  21   c.  The arm portion  21   c  is allowed to protrude forwardly from the transversely elongated rectangular hole-like opening  1   c  with the barrel-type operator  22  being inserted in the pipe-like base portion  21   a,  whereby the pipe-like base portion  21   a  of the cable driving arm  21  is allowed to rotate around an outer circumferential surface of the operator  22  within the support portion  1   d.    
         [0043]    Reference numeral  3  denotes a synthetic resin operation lever that is made open at ends thereof and which has a U-shaped cross-section, and a shaft hole  3   d  is formed in rear ends of the U-shaped opening. On the other hand, an arc-like projection  3   c  is provided at a front inner end portion and an arc hole  3   e  is formed rearward contiguously with the projection  3   c.  The U-shaped opening is placed so as to cover the cable driving arm  21 , and as shown in FIG. 7, and the projection  3   c  is then brought into abutment with a left side portion of the attachment portion  21   b  of the cable driving arm  21 . In this state, both the curved surfaces  1   b  of the support portion  1   d  are held between inner surfaces of the shaft holes  3   d  formed in the U-shaped opening. Furthermore, the support shaft  4  is then inserted into the operator  22  in this state and the ends of the support shaft  4  are inserted into both the shaft holes  3   d,  whereby the cable driving arm  21  is oscillatably and rotatably supported on the support portion.  
         [0044]    In addition, reference numeral  6  denotes, as with the first embodiment, a throttle cable, and this cable is inserted into the bracket from the left side thereof, and a drum member  6   a  at a tip thereof engages the attachment portion  21   b  of the driving arm  21  through the arc hole  3   e  of the operation lever  3 .  
         [0045]    Furthermore, reference numeral  9  denotes a screw for preventing the support shaft  4  from coming off the bracket and is adapted to be screwed thereinto from below. Reference numeral  23  shown in FIGS. 7 and 8 denotes a plate for closing the opening at a rear end on the inside of the support portion  1   d,  and the plate is fitted therein from the rear of the support portion  1   d  of the bracket  1  and is fixed thereto with plate screws  24 ,  24 .  
         [0046]    An operation of the throttle lever device according to the second embodiment will be described as below.  
         [0047]    The rider places his or her fingers on the operation lever  3  while grasping the grip  8  by his or her hand and pulls it toward him or her (rearward), the operation lever  3  rotates in a horizontal direction about the support shaft  4 , and the projection  3   c  pushes the attachment portion  21   b  of the cable driving arm  21  outwardly. This allows the cable driving arm  21  to rotate interlockingly with the operation lever  3 , and this in turn pulls the throttle cable  6 . This then opens a throttle (not shown) valve of a carburetor of an engine, the density of fuel that is supplied to the engine being increased, the engine speed being thereby increased.  
         [0048]    When the rider rotates the handlebar  7  to the left or right in the above state, the position of the fingers of the rider changes relative to the operation lever  3 . When this happens, assuming the barrel-type external surface, the operator  22  is allowed to oscillate back and forth in the pipe-like base portion  21   a  of the cable driving arm  21 , and therefore the support arm  4  in turn oscillates back and forth along the elongated hole  1   a  of the support portion together with the operator  22 , as shown in FIG. 9.  
         [0049]    Then, this allows the operation lever  3  rotatably supported on the support shaft  4  is allowed, as shown in FIG. 9, to rotate vertically within a range from (a) to (b) along the curved surfaces  1   b  of the support portion  1   d,  the operation lever  3  being thereby be allowed, as shown in FIG. 12, to follow the movements of the fingers of the rider based on the same principle as that described in the first embodiment.  
         [0050]    When this happens, the cable driving arm  21  is only allowed to rotate in the horizontal direction by the transversely elongated rectangular hole-like opening  1   c  and is restricted thereby with respect to the vertical movements, and therefore there is no risk of the pull amount of the throttle cable  6  being altered in conjunction with vertical movements of the operation lever  3 .  
         [0051]    Consequently, since the present invention is constructed as has been described heretofore, even when the rider rotates the handlebar  7  to the left or right, the operation lever  3  can follow the movements of the fingers and automatically oscillate vertically, thereby making it possible to provide a throttle lever device that exhibits good operability and which is markedly easy to use when compared with conventional throttle lever devices.  
         [0052]    Note that although in the above-mentioned description the throttle lever devices according to the present invention which is applicable for a water jet bike or a snowmobile is explained, the throttle lever device according to the present invention is also applicable for the another vehicle having a barhandle.  
         [0053]    While there has been described in connection with the preferred embodiment of the invention, it will be obvious to those bikelled in the art that various changes and modifications may be made therein without departing from the invention, and it is aimed, therefore, to cover in the appended claim all such changes and modifications as fall within the true spirit and scope of the invention.