Abstract:
There is disclosed a bicycle to which a trailer can be connected and from which the trailer can be detached without jeopardizing the integrity thereof. The bicycle includes a frame and two hooks. The frame includes two rear ends. Each of the hooks includes a first end detachably connected to a related one of the rear ends of the frame and a second end for connection to the trailer. A positioning device is used to precisely position each of the hooks with respect to a related one of the rear ends of the frame.

Description:
BACKGROUND OF INVENTION 
       [0001]    1. Field of Invention 
         [0002]    The present invention relates to a bicycle to which a trailer can be connected and from which the trailer can be detached without jeopardizing the integrity thereof 
         [0003]    2. Related Prior Art 
         [0004]    Referring to  FIGS. 1 and 2 , a conventional bicycle  1  includes a frame  2  and two hooks  3  for connecting a trailer to the frame  2 . The frame  2  includes a head tube  6 , a top tube  7  connected to the head tube  6 , a down tube  8  connected to the head tube  6 , a seat tube  9  connected to both of the tubes  7  and  8 , a seat stay  10  connected to the seat tube  9  and a chain stay  11  connected to the seat tube  9 . The seat stay  10  includes two branches each including a first end connected to the seat tube  9 . The chain stay  11  includes two branches each including a first end connected to the seat tube  9 . A second end of each of the branches of the seat stay  10  is joined to a second end of a related one of the branches of the chain stay  11  by a rear end  12  of the frame  2 . Each of the rear ends  12  of the frame  2  includes a recess  14  defined therein within upper and lower walls and a cutout  15  defined therein within the recess  14 . 
         [0005]    A connector  13  is located between the rear ends  12  of the frame  2 . The connector  13  includes a hub  131  formed thereon and a tunnel  16  defined therein. Each of the hooks  3  includes an aperture  19  defined in a first end  17  and a hook tip  20  formed at a second end  18 . The first ends  17  of the hooks  3  are disposed in the recesses  14  of the rear ends  12  of the frame  2 . A shaft  5  is inserted through the tunnel  16  of the connector  13 . The shaft  5  includes two threaded ends inserted through the cutouts  15  of the rear ends  12  of the frame  2  and the apertures  19  of the hooks  3 . Each of the threaded ends of the shaft  5  is driven in a screw hole  21  defined in a nut  4  so that the hooks  3  are connected to rear ends  12  of the frame  2 . The trailer includes two rods each including a recess defined therein for receiving the hook tip  20  of a related one of the hooks  3  so that the trailer is connected to the frame  2 . 
         [0006]    The integrity of the bicycle  1  might be jeopardized during the connection of the hooks  3  to the frame  2  for several reasons. 
         [0007]    Firstly, the hooks  3  are accessories that cannot be connected to the frame  2  without detaching the nuts  4  from the threaded ends of the shaft  5 . The nuts  4  are engaged with the threaded ends of the shaft  5  again after the threaded ends of the shaft  5  are inserted through the apertures  19  of the hooks  3 . The engagement of the nuts  4  with the threaded ends of the shaft  5  might not be done properly so that the shaft  5  and a rear wheel might be detached from the frame  2 . This is however undesirable. 
         [0008]    Secondly, the connection of the hooks  3  to the frame  2  inevitably increases the vibration of the bicycle  1 . This increased vibration contributes to the disengagement of the nuts  4  from the shaft  5  and therefore the detachment of the rear wheel from the frame  2 . 
         [0009]    Thirdly, the hooking of the trailer by the hooks  3  inevitably causes one of the hooks  3  to pivot in a wrong direction and contribute to the disengagement of the related nut  4  from the shaft  5 . 
         [0010]    Fourthly, the hooks  3  are not supported from below by any portions of the rear ends  12  of the frame  2 . 
         [0011]    The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art. 
       SUMMARY OF INVENTION 
       [0012]    According to the present invention, a bicycle includes a frame and two hooks. The frame includes two rear ends. Each of the hooks includes a first end detachably connected to a related one of the rear ends of the frame and a second end for connection to the trailer. A positioning device is used to precisely position each of the hooks with respect to a related one of the rear ends of the frame. 
         [0013]    The primary advantage of the bicycle according to the present invention is that the integrity thereof will not be jeopardized during the connection of the hooks to the rear ends and the detachment of the hooks from the rear ends. 
         [0014]    Other objectives, advantages and features of the present invention will become apparent from the following description referring to the attached drawings. 
     
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0015]    The bicycle according to the present invention will be described via the detailed illustration of four embodiments in comparison with a conventional bicycle referring to the drawings wherein: 
           [0016]      FIG. 1  is a perspective partial view of a conventional bicycle; 
           [0017]      FIG. 2  is an exploded view of the bicycle shown in  FIG. 1 ; 
           [0018]      FIG. 3  is a perspective partial view of a bicycle according to the first embodiment of the present invention; 
           [0019]      FIG. 4  is an exploded view of the bicycle shown in  FIG. 3 ; 
           [0020]      FIG. 5  is a perspective view of a trailer connected to the bicycle shown in  FIG. 3 ; 
           [0021]      FIG. 6  is a perspective view of the trailer detached from the bicycle shown in  FIG. 3 ; 
           [0022]      FIG. 7  is a perspective partial view of a bicycle according to the second embodiment of the present invention; 
           [0023]      FIG. 8  is an exploded view of the bicycle shown in  FIG. 7 ; 
           [0024]      FIG. 9  is a perspective partial view of a bicycle according to the third embodiment of the present invention; and 
           [0025]      FIG. 10  is a perspective partial view of a bicycle according to the fourth embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0026]    Referring to  FIGS. 3 through 6 , a trail  80  can be connected to and detached from a bicycle  30  according to a first embodiment of the present invention without jeopardizing the integrity of the latter. The bicycle  30  includes a frame  40 , two hooks  50  for connecting the trailer  80  to the frame  40  and two fasteners  60  for attaching the hooks  50  to the frame  40 . 
         [0027]    Referring to  FIGS. 3 and 4 , the frame  2  includes a head tube  41 , a top tube  42  connected to the head tube  41 , a down tube  43  connected to the head tube  41 , a seat tube  44  connected to the tubes  42  and  43 , a seat stay  45  connected to the seat tube  44  and a chain stay  46  connected to the seat tube  44 . The seat stay  45  includes two branches each including a first end connected to the seat tube  44 . The chain stay  46  includes two branches each including a first end connected to the seat tube  44 . A second end of each of the branches of the seat stay  45  is joined to a second end of a related one of the branches of the chain stay  46  by a rear end  47 . Each of the rear ends  47  includes a cutout  56  defined therein, a cavity  48  defined therein and a screw hole  49  defined therein within the cavity  48 . The cavity  48  of each of the rear ends  47  of the frame  40  is defined by a lower wall  66 , a front wall  68  and an upper wall  70 . 
         [0028]    Each of the hooks  50  includes an aperture  53  defined in a first end  51  and a hook tip  54  formed at a second end  52 . The first end  51  of each of the hooks  50  is located in the cavity  48  of one of the rear ends  47  of the frame  40 . The first end  51  of each of the hooks  50  is restrained by the walls  66 ,  68  and  70  of a related one of the rear ends  47  of the frame  40  and, more particularly, supported from below by the lower wall  66 . 
         [0029]    Each of the fasteners  60  includes a head  61  and a threaded body  62  extended from the head  61 . The threaded body  62  of each of the fasteners  60  is driven into the screw hole  49  of a related one of the rear ends  47  through the aperture  53  of a related one of the hooks  50 . 
         [0030]    Referring to  FIGS. 5 and 6 , the trailer  80  includes two rods  81  each including a recess  82  defined therein for receiving the hook tip  54  of a related one of the hooks  50 . Thus, the trailer  80  is detachably connected to the frame  40 . 
         [0031]    A connector such as the connector  13  shown in  FIGS. 1 and 2  can be located between the rear ends  47 . The connector includes a hub formed thereon and a tunnel defined therein. A shaft is inserted through the tunnel of the connector. The shaft include two threaded ends inserted through the cutouts  56  of the rear ends  47  and engaged with two nuts so that a rear wheel is connected to the rear ends  47 . 
         [0032]    It is clear that the connection of the hooks  50  to the rear ends  47  does not interfere with the connection of the shaft to the rear ends  47 . 
         [0033]    Referring to  FIGS. 7 and 8 , there is shown a bicycle according to a second embodiment of the present invention. The second embodiment is like the first embodiment except including two covers  90  for covering the cavities  48  and the fasteners  60  when then hooks  50  are detached from the rear ends  47 . Therefore, the bicycle is aesthetically pleasing. 
         [0034]    Referring to  FIG. 9 , according to a third embodiment of the present invention, a bicycle  100  includes a frame  110 , two hooks  130  and two fasteners  140  for attaching the hooks  130  to the frame  110 . The frame  110  includes a head tube  111 , a top tube  112  connected to the head tube  111 , a down tube  113  connected to the head tube  111  and a seat tube  114  connected to the tubes  112  and  113 . A chain stay  118  includes two branches each including a first end connected to the seat tube  114  and a second end. There are two supporting elements  117  each including a first end and a second end connected to the second end of a related one of the branches of the chain stay  118  by a rear end  119 . The rear ends  119  are similar to the rear ends  47 . A cushion  115  is connected to the down tube  113 . There are two rockers  116  each including a pivot  121  connected to the seat tube  114 , a first end  120  connected to the cushion  115  and a second end  122  connected to the first end of a related one of the supporting elements  117 . The hooks  130  are similar to the hooks  50 . The fasteners  140  are similar to the fasteners  60 . 
         [0035]    Referring to  FIG. 10 , there is a bicycle according to a fourth embodiment of the present invention. The fourth embodiment is like the first embodiment except two things. Firstly, each of the rear ends  47  is formed with a block  58  instead of the cavity  48 . Secondly, each of the hooks  50  includes a cavity  64  defined therein for receiving a related one of the block  58 . 
         [0036]    The bicycle according to the present invention exhibits several advantages. 
         [0037]    Firstly, the integrity of the bicycle will not be jeopardized during the connection of the hooks to the frame for several reasons. This is because the connection of the hooks to the frame does not interfere with the connection of the wheel to the frame. 
         [0038]    Secondly, the connection of the hooks to the frame is convenient since the fasteners are easily operable. 
         [0039]    Thirdly, the connection of the hooks to the frame is firm particularly because the hooks are supported from below by the lower walls of the cavities of the rear ends of the frame. 
         [0040]    Fourthly, the frame is aesthetically pleasing for using the covers to cover the cavities and fasteners when the hooks are detached from the frame. 
         [0041]    The present invention has been described via the detailed illustration of the embodiments. Those skilled in the art can derive variations from the embodiments without departing from the scope of the present invention. Therefore, the embodiments shall not limit the scope of the present invention defined in the claims.