Abstract:
An axle assembly is supplied capable of solving that troublesome mounting and dismantling works needing a wrench to screw fasten bolt. In the axle assembly, the present invention is to furnish nipping and holding member with collet shape on tubular body; to insert the nipping and holding member into penetrating hole of shaft mounting portion so as to shrink diameter; and to directly insert the tubular body into the penetrating hole. When moving fastening bar by operation of cam lever, both nipping and holding members nip and hold the shaft mounting portion. While dismantling, diameter shrinking part moves so as to make the nipping and holding member shrink diameter.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to an axle assembly to mount wheel hub of a bicycle to front fork or suspension fork. 
         [0003]    2. Related Background Art 
         [0004]    Conventional axle assembly has a tubular body and a pair of nipping and holding members with flange shape. In the conventional axle assembly, through inserting both ends of the tubular body into respective penetrating holes of a pair of shaft mounting portions (i.e. dropouts) furnished below a suspension fork; screwing the respective nipping and holding members into the both ends of the tubular body; and using the nipping and holding members to nip and hold the pair of shaft mounting portions, the tubular boby is installed on the pair of the shaft mounting portions. The tubular body rotatably supports a hub of wheel. 
         [0005]    The shaft mounting portions to mount such conventional axle assembly are formed into two separate structures in order to enable to shrink diameter of the penetrating holes of the shaft mounting portions. After inserted the tubular body into the penetrating hole, through integrating them by tightness of fastening bolt so as to shrink diameter of the penetrating hole, the tubular body is fixed strongly. 
         [0006]    However, as stated above, when screwing the nipping and holding member or performing the tightness of the fastening bolt, there is a problem that: not only a wrench is needed, but also time and exertion are needed for mounting and dismantling works of the tubular body. 
         [0007]    Recently, through furnishing throat for expanding diameter at both ends of the tubular body; moving a fastening bar furnished on the tubular body by a lever operation of a cam lever; expanding diameters of the both ends of the tubular body via the throats by pressing a taper washer connected to the fastening bar into the both ends of the tubular body; and squeezing peripheral surfaces of the both ends of the tubular body onto wall surfaces of the penetrating holes of the shaft mounting portions, the axle assembly having a structure in which the tubular body is installed on the shaft mounting portion is used practically. 
         [0008]    This axle assembly can dismantle the tubular body from the shaft mounting portions through restoring the cam lever to an open position and taking off the taper washer from the fastening bar, and it has comparatively simple structure for mounting and dismantling. However, since there are throats at both ends of the tubular body, there is a drawback that the strength of the tubular body becomes weak. 
       SUMMARY OF THE INVENTION 
       [0009]    It is, therefore, an objective of the invention to provide an axle assembly capable of solving the above problem. That is, the present invention has an objective to provide an axle assembly which enables to simply perform mounting and dismantling works with respect to shaft mounting portions and has excellent mechanical strength. 
         [0010]    According to the present invention, there is provided an axle assembly having a tubular body whose both ends are inserted into respective penetrating holes formed on a pair of shaft mounting portions, and rotatably supports wheel hub, comprising: 
         [0011]    a nipping and holding means that is installed on one end of the tubular body and is used for pressing edge of the penetrating hole of the shaft mounting portion on one side; 
         [0012]    a fastening bar that passes through the nipping and holding means and is placed inside the tubular body; 
         [0013]    a moving means that is placed to face to the nipping and holding means, is connected to one end of the fastening bar, and makes the fastening bar move inside the tubular body towards one end of the tubular body; 
         [0014]    a nipping and holding means with collet shape that has plural partition pieces and protrudes from other end of the tubular body so as to make the plural partition pieces can expand and shrink diameter; 
         [0015]    a pressing means that is connected to other end of the fastening bar, presses the nipping and holding means with collet shape by movement of the fastening bar, and presses the respective partition pieces to edge of the penetrating hole of the shaft mounting portion on the other side; and 
         [0016]    a diameter shrinking means that is installed on the pressing means so as to enable to move towards the other end of the tubular body, and couples with the plural partition pieces by moving so as to shrink diameter. 
         [0017]    3. Effect of the Present Invention 
         [0018]    According to the present invention, because the nipping and holding member with collet shape contacts to the wall surface of the penetrating hole of the shaft mounting portion and shrinks diameter, the tubular body and the nipping and holding member can be directly inserted into the penetrating hole. In addition, through shrinking diameter of the nipping and holding member with collet shape by a moving operation of the diameter shrinking means, the tubular body can be taken off from the penetrating holes. Therefore, it is possible to perform the installing and dismantling works simply. In addition, according to the present invention, because the pair of shaft mounting portions are nipped and held by two nipping and holding members without designing throats on the tubular body, the strength of installation is improved. 
         [0019]    The above and other objects and features of the present invention will become apparent from the following detailed description and the appended claims with reference to the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]      FIG. 1  is a sectional view of an axle assembly related to the present invention; 
           [0021]      FIG. 2  is a disassembled oblique view of an axle assembly; 
           [0022]      FIG. 3A  to  FIG. 3C  are sectional views for explaining mounting of this assembly onto shaft mounting portion and its movement; 
           [0023]      FIG. 4A  to  FIG. 4C  are diagrams for explaining dismantling of this assembly from the shaft mounting portion and its movement; 
           [0024]      FIG. 5  is a sectional view related to transformation embodiment of an axle assembly of the present invention; and 
           [0025]      FIG. 6  is an oblique view of fork structure related to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Embodiment 
       [0026]    Embodiments of the invention will be described in detail hereinbelow with reference to the drawings. 
         [0027]      FIG. 6  is an oblique view of fork structure installing an axle assembly  10  related to the present invention. 
         [0028]    In  FIG. 6 ,  1  shows front fork, on the front fork  1 , a suspension fork  2  with reverse U-shape is installed. On lower portions of respective forks of the suspension fork  2 , shaft mounting portions  3 A and  3 B are mounted. On the shaft mounting portions  3 A and  3 B, a penetrating hole  4  is respectively formed. An axle assembly  10  of the present invention is passed through the penetrating hole  4  of the shaft mounting portion  3 A on one side and is inserted into and passed through hub  5 , further, is passed though the penetrating hole  4  of the shaft mounting portion  3 B on the other side. 
         [0029]      FIG. 1  is a sectional view of the axle assembly  10  in the present invention, and  FIG. 2  is a disassembled oblique view of the axle assembly  10 . 
         [0030]    The axle assembly  10  has a tubular body  11  as shown in  FIG. 1  and  FIG. 2 . A nipping and holding member  12  is screwed into an opening of one end of the tubular body  11 . The nipping and holding member  12  has a tubular screwed part  12   a  and a flange part  12   b  which is protruded towards the radial direction while closing the opening. A sliding and contacting use plate  13  is fit to a concave of the flange part  12   b.    
         [0031]    The sliding and contacting use plate  13  is made from plastic, it is used to enable a cam lever  14  to slide smoothly. The cam lever  14  is composed of a cam part  14   a  and a lever  14   b.  The cam part  14   a  has a camshaft  15  eccentrically arranged. One end of a fastening bar  16  is inserted into the camshaft  15  and is fixed. The fastening bar  16  goes through the sliding and contacting use plate  13  and the screwed part  12   a  of the nipping and holding member  12 , and is coaxially arranged inside the tubular body  11 . Other end of the fastening bar  16  is protruded from the tubular body  11 . A screw slot  16   a  is furnished on the other end of the fastening bar  16 . 
         [0032]    The inner wall of other end of the tubular body  11  is formed with a slight thickness through a recess section. One end of coil spring  17  is contacted with the recess section. A cylindrical guide block  18  is pressed on other end of the coil spring  17 . As shown in  FIG. 2 , on the guide block  18 , six strips of guide grooves  18   a  radiating along radius direction are formed. 
         [0033]    The guide groove  18   a  of the guide block  18  is used to expand or shrink diameter of the nipping and holding member  19  with collet shape. That is, the nipping and holding member  19  is composed of six partition pieces  19   a  that protrude from the other end of the tubular body  11  and are arranged in concentric arrangement. Each partition piece  19   a  includes a flange part  20  having slant surface  20   a,  and a protuberance  19   b  fitting to the guide groove  18   a.    
         [0034]    A pressing member  21  is arranged to face to the nipping and holding member  19  with collet shape. The pressing member  21  is screwed with the screw slot  16   a  of the fastening bar  16 , and is composed of a taper part  21   a  and a serration shaft  21   b  for pressing respective inside slant surfaces  20   b  of plural partition pieces  19   a.    
         [0035]    A tubular shrinking member  22  is mounted on the pressing member  21 . The shrinking member  22  is fit to the pressing member  21  so as to be able to move towards the nipping and holding member  19 . An inside taper surface  22   a  is formed at front end of the shrinking member  22  for pressing respective slant surfaces  20   a  on the flange parts  20  of the plural partition pieces  19   a.  A serration boss  23  is screwed into rear end of the shrinking member  22 . The serration boss  23  is movably fit to the serration shaft  21   b  so as to allow the shrinking member  22  to move. 
         [0036]    In the axle assembly  10  of the present invention having the above-mentioned structure, as shown in  FIG. 1 , when the cam lever  14  locates in the open position, the nipping and holding member  19  with collet shape leaves one of the nipping and holding members  12 . 
         [0037]    Next, the operation of the axle assembly  10  in the present invention will be explained together with usage pattern. 
         [0038]      FIG. 3A  to  FIG. 3C  are sectional views for explaining mounting order of the axle assembly  10 . 
         [0039]    Firstly, as shown in  FIG. 3A , the axle assembly  10  is inserted into the penetrating hole  4  of the shaft mounting portion  3 A from the side of the shrinking member  22 , and is sequentially inserted into a hub  5  and the shaft mounting portion  3 B. During the aforesaid inserting work, in the nipping and holding member  19  with collet shape, the slant surfaces  20   a  of the flange parts  20  of the partition pieces  19   a  slidably contact with the inner wall surface of the penetrating hole  4  and with the inner wall surface of the hub  5 , the respective partition pieces  19   a  are guided towards the guide grooves  18   a  of the guide block  18  and approach each other. That is, because the nipping and holding member  19  automatically shrinks diameter, it is possible to make the axle assembly  10  pass through the both penetrating holes  4  and the hub  5  only by pushing and pressing the axle assembly  10 . 
         [0040]    Next, as shown in  FIG. 3B , when the axle assembly  10  is pushed and pressed, the flange part  12   b  of the nipping and holding members  12  on one side contacts with the edge of a penetrating hole of the shaft mounting portion  3 A, and it becomes impossible to push and press. In such pushing and pressing state, the flange part  20  of the nipping and holding member  19  with collet shape on the other side is protruded from the shaft mounting portion  3 B, and the respective partition pieces  19   a  are kept in diameter expansion state. 
         [0041]    Next, as shown in  FIG. 3C , the cam lever  14  is performed to rotate downward. By the operation, because the cam part  14   a  slidably contacts with the sliding and contacting use plate  13  while rotating; and the camshaft  15  separates from the sliding and contacting use plate  13 , the fastening bar  16  axially moves only the separate distance. Accordingly, because the pressing member  21  also moves and presses the nipping and holding member  19  with collet shape due to the taper part  21   a,  the nipping and holding member  19  (plural partition pieces  19   a ) moves against resilience of the coil spring  17  while expanding diameter. Therefore, because the flange part  20  of the nipping and holding member  19  is pressed to the edge of the penetrating hole  4  of the shaft mounting portion  3 B, the axle assembly  10  of the present invention can be mounted onto the suspension fork  2 . 
         [0042]    Next, dismantling work of the axle assembly  10  of the present invention will be explained by referring to  FIG. 4 . 
         [0043]    Firstly, as shown in  FIG. 4A , the cam lever  14  is performed to rotate upward. By the operation, the flange part  20  of the nipping and holding member  19  with collet shape releases to nip and hold the shaft mounting portion  3 B. In the case, because the nipping and holding member  19  is kept in a diameter expansion state, the nipping and holding member  19  is unable to pass through the penetrating hole  4 . 
         [0044]    Next, as shown in  FIG. 4B , the shrinking member  22  is moved leftward as shown in the diagram. By the operation, because the inner taper surface  22   a  of the shrinking member  22  presses the slant surfaces  20   a  in the flange part  20  of each partition piece  19   a  of the nipping and holding member  19 , the respective partition pieces  19   a  approach each other so as to shrink diameter. Accordingly, because it become possible to make the nipping and holding member  19  pass through the penetrating hole  4  of the shaft mounting portion  3 B, thereafter, as shown in  FIG. 4C , the axle assembly  10  can be dismantled only by pulling it out of the hub and the shaft mounting portion  3 B. 
         [0045]    As described in the above explanations, because the axle assembly  10  of the present invention can be easily mounted and dismantled on forks by one touch without designing breach on the tubular body, it is possible to obtain excellent installation strength. 
         [0046]      FIG. 5  is a sectional view showing transformation embodiment of the axle assembly  10  related to the present invention. 
         [0047]    In the transformation embodiment, taper surface  6  is designed on the edge of the penetrating hole  4  of both shaft mounting portions  3 A and  3 B, and taper surface  24  is designed to surface-contact with the taper surface  6  on flange parts  12 B and  20  of both nipping and holding members  12  and  19 . Accordingly, in a state that the axle assembly  10  is mounted onto both shaft mounting portions  3 A and  3 B, because the taper surface  6  contacts with the taper surface  24 , it is possible to more raise the strength of installation. 
         [0048]    In the above embodiment, the fastening bar  16  is moved through using the cam lever  14 , however, instead of the cam lever  14 , it is possible to furnish a rotatable operating section on one end of the tubular body  11 , to screw the fastening bar  16  into the operating section and to move the fastening bar  16  by a rotation operation of the operating section. 
         [0049]    Further, instead of the above-mentioned coil spring  17 , a spring section may also be furnished on the guide block  18 . 
         [0050]    Furthermore, it is possible to integrate the bottoms of plural partition pieces  19   a  in the nipping and holding member  19  so as to leave out the guide block  18 .