Patent Abstract:
A transmission mechanism is used in a bicycle having a frame. The transmission mechanism includes a quick assembly device including a central shaft, threaded collars, and a clip bracket, which is adapted to mount to a lower frame portion of the bicycle frame and a multi-mode mechanism, which is supported and fixed by the quick assembly device to provide the bicycle with multiple modes of pedaling.

Full Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a multipurpose transmission mechanism for a bicycle, and in particular to a transmission mechanism comprising a clip bracket that can be easily mounted to the bicycle frame to couple a multi-mode mechanism to the bicycle frame. 
         [0003]    2. The Related Arts 
         [0004]    Bicycles equipped with a gear-shifting mechanism are available in the market. The gear-shifting mechanism functions to switch the operation of the bicycle among different sprockets of different speed ratios. Besides switching among different sprockets of different speed ratios, the conventional gear-shifting mechanism does not function to alert operation mode of the bicycle. This makes it only possible to exercise particular muscles in riding the bicycle. Further, a single, fixed operation mode also makes long term riding boring. 
         [0005]    Thus, U.S. Pat. No. 5,088,340, entitled “Multipurpose Transmission Mechanism for Bicycles”, filed by the present inventor discloses a bicycle of which the operation mode can be changed. In other words, besides the conventional operation of continuous rotation of the pedals, other operation modes, including leverage mode and independent pedaling mode, are also available. Such variety of operation modes allows a bicycle rider to select the most suitable mode for riding and exercising. Such a transmission mechanism is also applicable to stationary bicycles. 
         [0006]    However, the conventional multipurpose suffers some drawbacks: 
         [0007]    (A) The bicycle disclosed in U.S. Pat. No. 5,088,340 requires a particular-purpose hub mounted in a rear wheel in order to allow the bicycle to carry out leverage mode operation and the particular-purpose hub is of high manufacturing costs as compared to regular hubs. 
         [0008]    (B) The rear wheel hub of the bicycle disclosed in U.S. Pat. No. 5,088,340 is of heavy weight, which makes it difficult to operate for certain users. 
         [0009]    (C) The multipurpose transmission mechanism of the bicycle disclosed in U.S. Pat. No. 5,088,340 is easy to malfunction. 
         [0010]    In view of the drawbacks, the present inventor teaches in U.S. patent application Ser. No. 11/281,470, entitled “Improved Multifunctional Pedaling Motion Bicycle” a bicycle transmission mechanism that effectively overcomes the drawbacks discussed above. However, the known transmission mechanism must work with a particular-purpose bicycle frame. Since it does not work with regular bicycle frame, it is difficult to get popularized. In addition, it is not possible for general consumers to do assembling by themselves. 
         [0011]    Thus, it is desired to further improve the bicycle transmission mechanism to allow easy and quick assembling and compatible wit the conventional bicycle frames. 
       SUMMARY OF THE INVENTION 
       [0012]    An object of the present invention is to provide a multipurpose transmission mechanism for a bicycle, which comprises a quick assembly device that allows quick assembling of a multi-mode mechanism to a regular bicycle frame so that a regular bicycle is provided with a clutch-based control mechanism that selectively allows pedal cranks of the bicycle to carry out a variety of pedaling modes, including the conventional alternate pedaling operation, synchronous and same-direction up and down pedaling operabon, rotary pedaling, both side alternate up-and-down pedaling, and single side up-and-down pedaling. In addition, assembling the transmission mechanism to a bicycle frame is easy, requiring no service of professional mechanics. Further, the transmission mechanism can be applied to regular bicycle frames. Thus, the present invention realizes utilization and low costs and can be popularized to be applied to all kinds of bicycles. 
         [0013]    The present invention has the following advantages: 
         [0014]    (1) While the conventional transmission mechanisms need parts of particular designs, the present invention allows for easy assembling by using a quick assembly device. The quick assembly device functions to support a multi-mode mechanism. With such an arrangement, even a regular bicycle frame can function as a multi-mode bicycle and can be assembled in an efficient manner. 
         [0015]    (2) The conventional transmission mechanism must be installed by professional mechanics. This increases the manufacturing costs and makes popularization difficult. The present invention, however, can be assembled by the general consumers. Thus, popularization can be effectively achieved. 
         [0016]    To realize the above object, in accordance with the present invention, a transmission mechanism for a bicycle having a frame is provided, wherein the transmission mechanism comprises a quick assembly device comprising a central shaft, threaded collars, and a clip bracket, which is adapted to mount to a lower frame portion of the bicycle frame and a multi-mode mechanism, which is supported and fixed by the quick assembly device to provide the bicycle with multiple modes of pedaling. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    The present invention will be apparent to those skilled in the art by reading the following description of a preferred embodiment thereof, with reference to the attached drawings, wherein: 
           [0018]      FIG. 1  is an exploded view of a multipurpose transmission mechanism constructed in accordance with the present invention; 
           [0019]      FIG. 2  is a cross-sectional view of a multipurpose transmission mechanism constructed in accordance with the present invention in an assembled condition; 
           [0020]      FIG. 3  is a perspective view of a clip bracket of the multipurpose transmission mechanism of the present invention; 
           [0021]      FIG. 4  an enlarged side elevational view of the multipurpose transmission mechanism mounted to a bicycle frame; 
           [0022]      FIG. 5  is a cross-sectional view of the multipurpose transmission mechanism of the present invention mounted to the bicycle frame; 
           [0023]      FIG. 6  is an enlarged cross-sectional view of a multi-mode mechanism of the transmission mechanism of the present invention, illustrating an operation thereof; 
           [0024]      FIG. 6A  is a side elevational view illustrating a pedaling mode of the present invention; 
           [0025]      FIG. 7  is an enlarged cross-sectional view of the multi-mode mechanism of the transmission mechanism of the present invention, illustrating another operation thereof; 
           [0026]      FIG. 7A  is a side elevational view illustrating another pedaling mode of the present invention; 
           [0027]      FIG. 8  is an enlarged cross-sectional view of the multi-mode mechanism of the transmission mechanism of the present invention, illustrating a further operation thereof; and 
           [0028]      FIG. 8A  is a side elevational view illustrating a further pedaling mode of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0029]    With reference to the drawings and in particular to  FIGS. 1 and 2 , which are an exploded view and a cross-sectional view, in an assembled condition, of a multipurpose transmission mechanism constructed in accordance with the present invention, the transmission mechanism is incorporated in a bicycle for switching the operation of the bicycle among different modes. The transmission mechanism comprises a quick assembly device  12  and a multi-mode mechanism  200 . The quick assembly device  12  comprises a central shaft  201 , threaded collars  30 ,  31 , and a clip bracket  40 . 
         [0030]    The transmission mechanism of the present invention is mounted to a lower frame portion  11  of a frame  10  of a regular bicycle or a stationary bicycle. To mount the transmission mechanism, retention rings  41   a,    41   b  of the clip bracket  40  are positioned in alignment with a bore (not labeled) of the lower frame portion  11  of the bicycle frame  10 . The central shaft  201  of the quick assembly device  12 , with the threaded collar  30 , which has bearing accommodated therein, mounted thereon in advance as shown in  FIG. 1 , is then inserted through both the retention rings  41   a,    41   b  of the clip bracket  40  and the lower frame portion  11  of the bicycle frame  10 . After the central shaft  201  extends through the retention ring  41   a,    41   b  of the clip bracket  40  and the lower frame portion  11  of the bicycle frame  10 , the threaded collar  31 , which has bearing accommodated therein, is fit over and mounted to an opposite ends of the central shaft  201 . A fixing ring  32  is then fit over and mounted to an outer end section of the threaded collars  30 ,  31  to “quickly” secure the retention rings  41   a,    41   b  in position. The opposite ends of the central shaft  201  are then fit through resilient elements  207   a,    207   b,  inner-threaded retention tubes  202   a,    202   b  of driving sprocket means  215  and gear-shifting means  215   a,  pedal cranks  243   a,    243   b,  locking members  203   a,    203   b,  and caps  255   a,    255   b.    
         [0031]    Clips  401   a,    401   b  are arranged outside the lower frame portion  11  of the bicycle frame  10  at locations corresponding to the clip bracket  40 . The retention rings  41   a,    41   b  of the clip bracket  40  have downward extensions forming therebetween a rear support block  42  which defines inner-threaded holes  42   a,    42   b  and also have upward extensions forming therebetween a front support block  43 , which defines an inner-threaded hole  43   a.  The clips  401   a,    401   b,  which constitute a control mechanism  400 , comprises a support block  406  that is attached to the clip bracket  40 . A control cable  402  has lower branches (not labeled) respectively secured to the clips  401   a,    401   b.    
         [0032]    With additional reference to  FIG. 3 , which shows a perspective view of the clip bracket  40 , as well as  FIGS. 4 and 5 , which are an enlarged side elevational view and a cross-sectional view of the transmission mechanism of the present invention mounted to the bicycle frame, the clip bracket  40  is provided, corresponding to the opposite sides of the lower frame portion  11  of the bicycle frame  10 , with the retention rings  41   a,    41   b,  which are positioned in alignment with the opposite ends of the bore of the lower frame portion  11 , and are supported by the threaded collars  30 ,  31  and secured against the lower frame portion  11  by the fixing rings  32 , whereby the clip bracket  40  is secured to the lower frame portion  11  of the bicycle frame  10 . 
         [0033]    The support block  406  of the clips  401   a,    401   b  of the control mechanism  400  is secured by bolts that engages inner-threaded holes  406   a,    406   b  defined in the support block  406  and put in alignment with the inner-threaded holes  42   a,    42   b  of the rear support block  42  of the clip bracket  40 . The control cable  402  is then attached to the clips  401   a,    401   b  and thereafter, a front end of the control cable  402  is extended through the inner-threaded hole  43   a  of the front support block  43  of the clip bracket  40  to allow the control cable  402  to control the operation of the clips  401   a,    401   b.    
         [0034]    Referring to  FIGS. 1 ,  2 , and  5 , the multi-mode mechanism  200  has a symmetrical arrangement on opposite sides of the central shaft  201 , except the driving sprocket means  215  and the gear-shifting means  215   a.  Only one side of the symmetric arrangement will be explained as an example to describe the present invention, and it is noted that although only reference numerals with a postfix of “b” will be described, counterpart and symmetric reference numerals with a postfix of “a” are of identical construction and operation. The multi-mode mechanism  200  comprises a resilient element  207   b  (as well as a counterpart and symmetric element  207   a  on the other side, see  FIG. 1 ), a driving disk  208   b,  a clutch ring block  224   b,  a control block  223   b,  and a connection rod  217   b.  A controller (not shown) can be mounted at any suitable location on the bicycle frame  10  to be accessed and operated by a user to operate the control cable  402  to for example release the clips  401   a,    401   b  and simultaneously, the resilient element  207   b  urges the driving disk  208   b  to move and the clips  401   a,    401   b  are simultaneously moved outward whereby the clutch ring block  224   b  is forced to abut against a recess formed on a side surface of the pedal crank  243   b.  The driving disk  208   b  engages a transmission block  225   b.  In this condition, the driving power induced by the user&#39;s pedaling is transmitted through the pedal crank  243   b  to drive the driving sprocket means  215 , while the power from the other pedal crank  243   a  is transmitted through the transmission block  225   b  to drive the driving sprocket means  215  (see  FIGS. 5 ,  6 , and  6 A). This allows the pedal cranks  243   a,    243   b  to do up and down operation in the same direction for driving a rear wheel through the driving sprocket means  215 . 
         [0035]    Referring to  FIGS. 7 and 7A , when the control cable  402  is operated to cause the clips  401   a,    401   b  (see  FIG. 5 ) to control the driving disk  208   b  to drive the clutch ring block  224   b  through the connection rod  217   b,  and making the driving disk  208   b  displaced away from the transmission block  225   b  and disengaging from the transmission block  225   b,  the pedal cranks  243   a,    243   b  are allowed to operate independently. Thus, the pedal cranks  243   a,    243   b  can independently drive the driving sprocket means  215  whereby the driving sprocket means  215  can obtain continuous or intermittent supply of power and the pedal cranks  243   a,    243   b  can be pedaled up and down independently or rotated independently to realize various modes of pedaling operation that transmits power to the rear wheel through the driving sprocket means  215 . 
         [0036]    Referring to  FIGS. 8 and 8A , when the control cable  402  drives the clips  401   a,    401   b  to control the driving disk  208   b  and the connection rod  217   b  to engage the clutch ring block  224   b  with the control block  223   b,  the pedal cranks  243   a,    243   b  are switched to a regular opposite-positioned condition whereby the pedal cranks  243   a,    243   b  can be pedaled alternatively to rotate continuously for supplying power to the driving sprocket means  215 , which is then transmitted to the rear wheel. 
         [0037]    To summarize, the present invention offers the following advantages: 
         [0038]    (1) The first advantage of the present invention is that a conventional and regular bicycle frame can be used to combine with the central shaft and the threaded collars of the quick assembly device to mount a clip bracket thereon so that no specific-purpose bicycle frame is needed in coupling the multi-mode mechanism to the regular bicycle frame. Thus, the construction is simplified and the assembling is made easy, both facilitating popularization of bicycle products of the present invention and enhancing economic values of the bicycle. 
         [0039]    (2) The second advantage of the present invention is that the transmission mechanism of the present invention can be easily mounted to a regular bicycle frame by the general consumers, which facilitates popularization. In addition, the bicycle of the present invention can be of various modes of pedaling, which enhances pleasure of riding and appealing to the general consumers. 
         [0040]    (3) The third advantage of the present invention is that the quick assembly device of the present invention can also work with a stationary bicycle, providing the stationary bicycle with different modes of pedaling so that a user may select different mode of pedaling depending upon the user&#39;s mood and desire. In addition, the various modes of pedaling provided by the present invention also allows a user of the stationary bicycle to carry out training and exercising of different muscles of the user. 
         [0041]    Although the present invention has been described with reference to the preferred embodiment thereof, it is apparent to those skilled in the art that a variety of modifications and changes may be made without departing from the scope of the present invention which is intended to be defined by the appended claims.

Technology Classification (CPC): 8