Abstract:
An auxiliary supporting device is designed for supporting and fixing a bicycle. When a user rides a bicycle which is set up on this supporting device, the bicycle will neither move forward nor fall down if the user applies the skill of riding bicycle. This device can be used to train a rider for better bicycle controllability or to let user exercise at a fixed location.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an auxiliary supporting device of a bicycle and, more particularly, to an auxiliary supporting device of a bicycle for exercise. 
     2. Description of Related Art 
     With the progress of science and technology, people become busier and have less time to go out exercising. Moreover, because high buildings stand in great numbers in cities, there are less and less places where people can exercise. 
     Therefore, many kinds of exercise equipments have sprung up in the market such as exercise bicycles, treadmills, and so on. People can use these equipments to exercise indoors. 
     In the disclosure of U.S. Pat. No. 6,612,970, an adjustable stationary exercise bicycle is proposed. As shown in  FIG. 1 , a bicycle  10  comprises a seat  102 , handlebars  104 , two connected pedals  106  and a wheel  108 . All the above components are disposed on a lower frame  110 . This bicycle, however, cannot swing along an imaginary axis direction of the wheel contact surface. 
     In the disclosure of U.S. Pat. No. 6,736,761, a stationary bicycle resistance generator is proposed. As shown in  FIG. 2 , a stationary bicycle resistance generator  20  comprises two struts  202  and two retaining sleeves  204 . The rear wheel axle of a bicycle is fixed on the retaining sleeves  204 . The bicycle, however, cannot swing left or right on the stationary bicycle resistance generator  20 . 
     In the disclosure of U.S. Pat. No. 6,126,577, an exercise stationary bicycle is proposed. As shown in  FIG. 3 , a bicycle  30  comprises a seat  302 , handlebars  304 , two connected pedals  306  and a wheel  308 . All the above components are disposed on a lower frame  310 . This frame  310  is supported and balanced on a base  314  by a left and a right hydraulic cylinders  312 . Although this bicycle  30  can swing left or right, it is not based on the balance principle of bicycle (i.e., a bicycle is balanced by the moment of inertia generated through rotation of wheels), but makes use of the supporting and balancing function of the two hydraulic cylinders  312 . 
     The present invention aims to propose an auxiliary supporting device of a bicycle to solve the above problems in the prior art. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to propose an auxiliary supporting device of a bicycle to accomplish the exercising effect. 
     Another object of the present invention is to propose an auxiliary supporting device of a bicycle, in which the front and rear wheels of the bicycle rotate synchronously so that a user can simulate the exercise of riding a bicycle at a fixed location to accomplish the exercising effect. 
     Yet another object of the present invention is to propose an auxiliary supporting device of a bicycle, in which the handlebars of the bicycle can be turned left or right so that a user can apply the skill of riding bicycle. 
     Still yet another object of the present invention is to propose an auxiliary supporting device of a bicycle, in which the bicycle can swing along an imaginary axis (embodied with a main rotating shaft) direction of the wheel contact surface to train a user his sense of balance. 
     To achieve the above objects, the present invention proposes an auxiliary supporting device of a bicycle, which comprises a base, two rolling elements and a supporting element. The base is connected with a main rotating shaft having a protruding part, which is engaged with a wheel axle of a rear wheel of a bicycle. The two rolling elements are disposed on the base and located below the protruding part so that partial wheel surface of the rear wheel is located on the rolling element. The supporting element is disposed above the main rotating shaft. The supporting element is engaged with a front wheel of the bicycle. The supporting element includes a rotating element with a rolling element. The front wheel is located on the rolling element. A rotating guide wire is used to connect the rear wheel rolling elements and the front wheel rolling element. When a user sits on the bicycle and moves the pedals, the rear wheel leads the rolling element to roll and further drives front wheel rotate via the rotating guide wire and front wheel rolling element, thereby accomplishing synchronous rotation of the front and rear wheels. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing, in which: 
         FIG. 1  is a perspective structure diagram of an adjustable stationary exercise bicycle in the prior art; 
         FIG. 2  is a perspective structure diagram of a stationary bicycle resistance generator in the prior art; 
         FIG. 3  is a perspective structure diagram of an exercise stationary bicycle in the prior art; 
         FIG. 4  is a top view of the present invention; 
         FIG. 5  is a side view of the present invention; 
         FIG. 6  is a side view according to an embodiment of the present invention; 
         FIGS. 7(   a ) and  7 ( b ) are diagrams showing a front view of supporting element and a bicycle sway on the present invention; 
         FIG. 8  is a diagram showing a back view of the present invention; and 
         FIG. 9  is a perspective view of a supporting element, a rolling element, and a bearing of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In order to help people achieving the effect of exercise indoors, the present invention proposes an auxiliary supporting device of a bicycle. As shown in  FIGS. 4 ,  5  and  6 , an auxiliary supporting device  50  comprises a base  502  with a main rotating shaft  503 . The main rotating shaft  503  has a protruding part  504 , and a rear wheel  602  of a bicycle  60  is engaged on the protruding part  504 . Two rolling elements  506  are disposed on the base  60  and located below the protruding part  504  such that rear wheel  602  of the bicycle  60  is located on the rolling elements  506 . The main rotating shaft  503  has also a supporting element  508 . The supporting element  508  includes a rotating element connected with a rolling element  510  for engaging a front wheel  604  of the bicycle  60  such that front wheel  604  is located on the rolling element  510 . 
     The main rotating shaft  503  can be either free rotated to let bicycle  60  sway (As shown in  FIGS. 7(   a ) and  7 ( b ), the bicycle  60  can swing along the axle of the main rotating shaft  503 .) or fixed by a fixing element  512  like a tenon joint such that it cannot rotate. The fix element  512  can be applied in the cases: (1). When the bicycle  60  is not in use, the main rotating shaft  503  is fixed to prevent the bicycle  60  from falling down. (2). It also can be used to train a user who cannot ride bicycle to move the pedals of the bicycle  60  without worrying bicycle  60  falls down. 
     In addition to the function of bicycle  60  swing along the axle of main rotating shaft  503 , the supporting element  508  can also be engaged with the main rotating shaft  503  via a bearing  516  so as to rotate along the direction perpendicular to the main rotating shaft  503 , thereby making the handlebars of the bicycle  60  be able to turn left and right. 
     Besides, the rolling element  510  is connected to the rolling elements  506  via a rotating guide wire  514 . The rolling elements  506  and  510  are rollers. When a user moves the pedals of the bicycle  60 , the rear wheel  602  leads the rolling elements  506  to roll and further drives the rotating element  510  to rotate through a rotating guide wire  514  so as to let the front wheel rotate therewith, thereby accomplishing synchronous rotation of the front and rear wheels. 
     As shown in  FIG. 8 , the rear wheel  602  of the bicycle  60  is supported by the two rolling elements  506 , and the engagement between the rear wheel of the bicycle  60  and the protruding part  504  is accomplished by means of piston and bushing (the engagement between the front wheel axle of the bicycle  60  and the supporting element  508  is also accomplished by means of piston  518  and bushing  520 , as shown in  FIG. 9 ) such that the weight of a rider and the bicycle  60  can be directly transmitted to the rolling elements  506 . The rear wheel  602  of the bicycle  60  rotates to lead the rolling elements  506  to roll. The roughness degree of the surface of the rolling elements  506  makes the rider feel as though he is rides on the road. 
     To sum up, when a rider uses this auxiliary supporting device of a bicycle (with not fixed by a fixing element  512 ), the principle of the bicycle  60  won&#39;t fall down is the same as that of riding a bicycle on the road. They both exploit the moment of inertia generated through rotation of the front and rear wheels. The present invention utilizes the rotation of the rear wheel of the bicycle to lead the rolling elements to roll and further drives the front wheel to rotate via the rotating guide wire and front wheel rolling element. By this auxiliary supporting device of a bicycle, the bicycle can swing and the handlebars of the bicycle can turn left and right. Therefore, the user can simulate the exercise of riding bicycle at a fixed location. 
     Although the present invention has been described with reference to the preferred embodiment thereof, it will be understood that the invention is not limited to the details thereof. Various substitutions and modifications have been suggested in the foregoing description, and other will occur to those of ordinary skill in the art. Therefore, all such substitutions and modifications are intended to be embraced within the scope of the invention as defined in the appended claims.