Abstract:
The present invention relates to a bicycle wheel hub with strengthening mechanism which includes a regulating spindle connected at the front and rear forks of the shaft of the wheel hub. Based on the opening or closed end of he fork, the shaft is adjusted from the original position to the appropriate position. Accordingly, the engagement among the chainwheel, the freewheel and the drive chain is slightly adjusted to a better condition. Besides, both ends of the shaft or one end thereof near the freewheel is able to be larger than the diameter of portion receiving the bearing by means of the adjustment of the screw joint so that the supporting strength is much improved.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a bicycle wheel hub with strengthening mechanism, and more particularly, to a wheel hub which adjusts the engagement among the chainwheel, the freewheel and the drive chain to a better state while the supporting strength of the joint between the frame and the shaft can be improved.  
           [0003]    2. Description of the Prior Art  
           [0004]    In the whole frame of the bicycle, the power is transmitted to the freewheel by means that the chainwheel is engaged with the chain. Thus, the bicycle moves forward.  
           [0005]    Conventionally, the front and rear forks of the bicycle frame are connected to the shafts of the bicycle wheel hubs. Moreover, the bicycle wheel hub utilizes the spokes and tire to join together as one body. Therefore, the shaft of the bicycle wheel hub will leave the prearranged central position degree by degree because the bicycle jolts over the rough roads, the bike-rider intentionally makes the wheel spring ups and downs. Accordingly, an unnecessary wearing during the power transmission is produced so that the bike-riding will be more and more strenuous. For the serious case, the engagement of the wheel teeth and the drive chain will easily fail, thereby causing the malfunction of the bike.  
           [0006]    In addition, the shaft is the joint of the bicycle wheel hub and the front and rears forks. Also, it is the force-exerting and resisting point. Under restriction of the standard specification of the freewheel, bearing, etc., the diameter of two ends doesn&#39;t exceed the diameter of the mounting portion of the bearing. Although it won&#39;t be broken down because of the springing (or jumping) ride, the supporting force is still insufficient, especially, when the bike-riders stand on the add-on rods at two ends thereof. Accordingly, the smoothness during the riding is seriously influenced.  
         SUMMARY OF THE INVENTION  
         [0007]    It is a primary object of the present invention to remove the above-mentioned drawbacks and to provide a bicycle wheel hub which can adjust the engagement among the chainwheel, the freewheel and the drive chain to a better state, thereby reducing the possibility of the disengagement of the chain.  
           [0008]    It is another object of the present invention to provide a bicycle wheel hub which improves the supporting strength of the joint between the frame and the shaft. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    The accomplishment of this and other objects of the invention will become apparent from the following description and its accompanying drawings of which:  
         [0010]    [0010]FIG. 1 is a perspective view of the shaft of the present invention;  
         [0011]    [0011]FIG. 2 is a perspective view of another shaft of the present invention;  
         [0012]    [0012]FIG. 3 is a sectional assembly view of the wheel hub and the shaft while the rear fork is marked by dotted line;  
         [0013]    [0013]FIG. 4 is a sectional view of the joint portion with a treading rod;  
         [0014]    [0014]FIG. 5 is a sectional view of the joint among the regulating mechanism, the shaft and the fork; and  
         [0015]    [0015]FIG. 6 is a sectional view of the joint among another regulating mechanism, the shaft and the fork. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0016]    Referring to FIG. 1, a strengthened shaft  10  is divided into an embedded portion  11  and two threaded joint portions  12 . The threaded joint portions  12  each include two locating portions  15  being recess-shaped and disposed parallel to each other. A smooth mounting portion  14  is formed between the threaded portion and the embedded portion  11 . The free end of the mounting portion  14  of a threaded joint portion  12  is provided with a threaded portion  13  in the axial direction.  
         [0017]    An adjustable shaft  10 , as shown in FIG. 2, is also divided into an embedded portion  11  and two threaded joint portions  12 . Besides, the threaded joint portions  12  each have two locating portions  15  being recess-shaped and disposed parallel to each other and a smooth mounting portion  14 . The adjustable shaft  10  differs from the strengthened shaft  10  in that the former is formed in a body and is provided with a regulating hole  16  passing through the threaded portion between both locating portions  15 .  
         [0018]    A combination shaft  10  of the above two is shown in FIG. 3. It&#39;s apparent from FIG. 3 that the portion of the threaded joint portion  12 , whose diameter greater than the mounting portion  14 , is inserted from one end of the wheel hub (a) with the freewheel-fixing portion (e) so that the mounting portion  14  is attached to the bearing (b) in the bearing groove (d). Another portion is inserted from the opposing end of the wheel hub (a) in order for the embedded portion  11  to connect with the threaded portion (not shown) in a body. Thereafter, a screw (c) together with a washer is driven from both ends thereof into the bearing (b) for completing the assembly procedure.  
         [0019]    The center of both ends of the shaft  10  is situated at a phantom line and won&#39;t be deviated by means of the design of the bearing groove (d) of the wheel hub (a) and the assembly of the standard bearing (b) and the mounting portion  14 . The washer and the screw (c) will enable both locating portions  15  to adjust to a horizontal phantom line for connecting with the rear fork (f) (shown with dotted line).  
         [0020]    The corresponding relationship of the joint between the fork and the shaft  10  can be shown in FIGS. 4 and 6. The thickness between both locating portions  15  of the threaded joint portion  12  is the same to or slightly smaller than the length of an opening (g) of the rear fork (f) so that the former can be inserted into the opening. A regulating spindle  20  includes a drive end  21  in shape of polygonal groove while the other end thereof is screwed with the regulating hole  16  and supports against the closed end of the opening (g) of the rear fork (f).  
         [0021]    When the user utilizes a tool to drive the drive end  21  to turn the regulating spindle  20 , a pulling force in the direction of the chainwheel to the wheel hub (a) together with the shaft is created because of the engagement of the chainwheel, the freewheel (not shown) and the chain. However, it won&#39;t be moved as the regulating spindle  20  supports against the closed end of the opening (g) of the rear fork (f).  
         [0022]    If the drive end  21  is turned to couple with the regulating hole  16  to screw in the left direction for displacement, the locating portions  15  will enable the threaded joint portion  12  to move in the same direction on the top and bottom edges of the opening (g). At this time, the clearance between the shaft of the wheel hub (a) and the shaft center of the chainwheel will be enlarged. In the contrary, if the regulating spindle  20  is turned to move the threaded joint portion  12  forward in the right direction of the figure, the clearance between the shaft of the wheel hub (a) and the shaft center of the chainwheel will be shortened.  
         [0023]    When the threaded joint portion  12  is moved forward on the stationary regulating spindle  20 , the increased distance of the wheel hub on the rear fork (f) is slight. However, it has the following advantages:  
         [0024]    1. The height value of the teeth of the chainwheel or the freewheel is not large. Thus, the forward and rearward movement distance on the regulating spindle  20  is enough to adjust the engagement of the teeth and the chain holes to a better state, thereby reducing the possibility of disengagement.  
         [0025]    2. The power is transmitted from the chainwheel to the freewheel by means of the chain. If the engaging condition can be adjusted by the bike-rider himself after using the bike, the power transmission will be smoother. Also, the service life will be prolonged.  
         [0026]    Another corresponding relationship of the joint between the fork and the shaft  10  is shown in FIG. 5. Similarly, the opening of the rear fork (f) of both locating portions  15  of the threaded joint portion  12  slides into the opening (g). A regulating spindle  20  includes a polygonal drive end  21  at one end thereof while the other end thereof passes through the hole  26  in the middle of the locating block  24  and is screwed with the regulating hole  16 . The locating block  24  includes a groove  25  on the surface of the hole  26  so that it can be mounted on the opening (g) of the rear fork (f). The drive end  21  supports against the outer rim of the locating block  24  by means of the pulling force among the chainwheel, the freewheel and the chain.  
         [0027]    Based on the above-mentioned structure, it&#39;s no more important if the other end of the regulating spindle  20  supports against the closed end of the opening (g) of the rear fork (f) because the polygonal drive end  21  supports against the outer rim of the locating block  24 . Besides, the operation steps and advantages thereof are identical so that no further descriptions are given hereinafter.  
         [0028]    In addition, it&#39;s apparent from FIGS. 3 and 4 when the bike-rider want to add a treading rod (h) to the exposed portion of the threaded joint portion  12  with enlarged diameter on the shaft  10 , one end of the neighbored rear fork (f) can be mounted or screwed on the threaded joint portion  12 . Also, the both are screwed together by means of the locking element  22  of the polygonal drive head  23 .  
         [0029]    The advantages of the wheel hub (a) in comparison with the conventional lie in:  
         [0030]    1. Supposed that the diameter of the threaded joint portion  12  is enlarged from 14 mm to 20 mm, the clearance of the diagonal line or the opposing sides is somehow enlarged when the conventional standard nut is used to lock the treading rod (h) and the shaft  10 . The inner diameter of the treading rod (h) must also be enlarged to receive the socket or wrench for locking. However, the aforementioned drive head  23  of the locking element  22  can be designed as standard specification so that the locking procedure won&#39;t be influence if the maximal outer diameter at the other end is identical to the inner diameter of the treading rod (h).  
         [0031]    2. The enlarged diameter of the threaded joint portions  12  at both ends of the shaft  10  can strengthen the structure of the fork. Also, more body weight on the treading rod (h) can be supported. This can&#39;t be reached by the conventional wheel hub (a) whose diameter at both end must be smaller than the shaft of the mounting portion.  
         [0032]    Many changes and modifications in the above-described embodiments of the invention can, of course, be carried out without departing from the scope thereof. Accordingly, to promote the progress in science and the useful arts, the invention is disclosed and is intended to be limited only by the scope of the appended claims.