Abstract:
The present invention relates to the drive assembly coupled with the pedal thereon the frame, and the transmission assemblies rotated by the drive assembly. Thereby to step on the pedal repeatedly rotates the transmission assemblies to make the wheel rotate in single direction. Therefore, the invention can first enhance the operating stability and then get the exercise effect while the user kicks the ground to propel the pedal scooter and steps on the pedal repeatedly.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a scooter. In particular, it relates to a pedal scooter with enhanced stability and durability. 
   2. Description of the Related Art 
   Referring to  FIG. 1 , a conventional scooter comprises a frame  11 , a steering rod  12  and a pair of wheels  13 ; wherein the steering rod  12  is pivoted to the frame  11 , and a handlebar  121  is disposed on the steering rod  12 . The pair of wheels  13  is pivotally coupled to two sides of the frame  11 ; one of the wheels  13  is connected to the steering rod  12  for controlling the moving direction of the scooter. In operation, the user first propels the scooter to move forwards, when the moving speed becomes slower the user kicks on the ground with one foot to propel again. The aforesaid movement is repeated again and again to maintain the speed of the scooter. However, propelling with one foot has limitation in increasing the speed of the scooter; in addition, the balance of the scooter with one foot is not stable. 
   Accordingly, there is a prior art disclosed a power scooter with an improved transmission structure. Referring to  FIGS. 2 and 3 , the power scooter  2  comprises a frame  21 , a pair of wheels  22  connected to the frame  21 , a handlebar  23 , an elastic body  25 , a pedal assembly  26  and a one-way transmission bearing  27 . The pedal assembly  26  comprises two pedals  261  disposed to both sides of the frame  21 , and a transmission sprocket  262  extending from the pedals  261  and engaged with the one-way transmission bearing  27 . Further, the one-way transmission bearing  27  and the wheel  22  are coupled together; therefore, while the one-way transmission bearing  27  rotates in a specific direction, it also rotates the wheel  22 . Along with the elastic body  25  set between said frame  21  and said pedals  261 , the pedals  261  will then be stepped repeatedly in operation. 
   While in use, repeat stepping on the pedals  261  drives the transmission sprocket  262  and the one-way transmission bearing  27  to rotate in a specific direction, which in turn further rotates the wheels  22  forwards. However, due to the two pedals  261  disposed on both sides of the frame  21 , the space for standing is quite limited. 
   Due to the limited space for standing, it is quite difficult for a user to step on the pedals  261  for forward moving. While a user steps on the pedals  261  repeatedly, the frame  21  will be out of balance and shake. In addition, because the wheels  22  of conventional scooter are over small, safety becomes a concern. 
   SUMMARY OF THE INVENTION 
   The present invention provides a pedal scooter which relies on a user&#39;s weight for stepping on the pedal repeatedly for rotation power of wheels. The stepping process is stable and can achieve great exercising effect. 
   The present invention comprises a frame, a steering rod, a plurality of wheels, a drive assembly, and two transmission assemblies disposed on the frame. The drive assembly comprises a pedal pivotally disposed on the frame, and one elastic body connected between the pedal and the frame. Further, the transmission assemblies are disposed on both sides of the wheels of the frame; each of the aforesaid transmission assembly comprises a curved rack connected to the pedal, a first sprocket wheel engaging with the curved rack on the frame, a second sprocket wheel engaging with the first sprocket wheel, a third sprocket wheel disposed on the wheel and engaging with the second sprocket wheel, and a one-way transmission bearing disposed between the first and second sprocket wheels. Therefore, a user only needs to step on the pedal repeatedly, and the elastic body disposed between the pedal and the frame springs up and down to make the two transmission assemblies rotate, and make the wheels rotate. Accordingly, this invention has the benefit of being stable in operation and of achieving greater exercising effect. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawing is included to provide a further understanding of the invention, and constitutes a part of this specification. The drawing illustrates an embodiment of the invention and, together with the description, serves to explain the principles of the invention. In the drawing, 
       FIG. 1  is a plan view of a conventional scooter; 
       FIG. 2  is an another perspective view of a conventional power scooter; 
       FIG. 3  is a perspective diagram showing the transmission structure of the conventional power scooter; 
       FIG. 4  is a perspective diagram showing a preferred embodiment of the present invention; 
       FIG. 5  is a perspective diagram showing the drive assembly and the transmission assembly of the present invention; 
       FIG. 6  is a perspective diagram showing the one-way transmission bearing of the present invention; 
       FIG. 7  is a cross-section view showing the one-way transmission bearing engaging with second sprocket wheel of the present invention; 
       FIG. 8  is perspective diagram showing the present invention being folded according to the preferred embodiment; and 
       FIGS. 9 and 10  is a perspective view showing the transmission assembly rotating of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to  FIG. 4 , the preferred embodiment of the present invention comprises one frame  51 , one steering rod  52 , a plurality of wheels  53 , one drive assembly  54  and two transmission assemblies  55 . The steering rod  52  is pivotally disposed on the frame  51 , and the steering rod  52  is disposed on the handlebar  521 . Further, the wheels  53  are pivotally coupled to the frame  51  and the steering rod  52  to control the advancing direction with the steering rod  52 . 
   Referring to  FIG. 5 , the drive assembly  54  comprises one pedal  541  disposed on the frame  51  pivotally, and one elastic body  542 (such as spring) coupled between the said pedal  541  and the said frame  51 . A mudguard  543  is disposed on the frame  51  and extends to the wheel  53 . While an external force applies to the pedal  541 , it will return to the original position due to the reverse force of the elastic body  542 . Meanwhile, the splash dirt from the wheel  53  will be blocked by the mudguard  543 . 
   Referring to  FIGS. 5 and 6 , said two transmission assemblies  55  are disposed on each of the two sides of the said wheel  53 . Each of the transmission assemblies  55  comprises a curved rack  551  connected to the pedal  541 , a first sprocket wheel  552  engaged with the curved rack  551 , a second sprocket wheel  553  engaged with the first sprocket wheel  552 , a third sprocket wheel  554  disposed to the wheel  53  and engaged with the second sprocket wheel  553 , and a one-way transmission bearing  555  disposed between the first and second sprocket wheels  552 ,  553 . 
   Accompanying with  FIG. 7 , the aforesaid one-way transmission bearing  555  comprises a retaining sheath  556 , a spindle  557  located through the retaining sheath  556 , a plurality of rollers  558  disposed in the retaining sheath  556 , and a rotated sheath  559  disposed outside the retaining sheath  556  and driven by the second sprocket wheel  553 . The retaining sheath  556  has a plurality of apertures  5561  thereon to retain the said rollers  558 . A plurality of recesses  5591  are disposed inside the rotated sheath  559 . Furthermore, each said recess  5591  has a bottom wall  5592 , a side surface  5593  extending upwardly from the bottom wall  5592 , and an inclined surface  5594  extending upwardly from the bottom wall  5592  and connecting with the side surface  5593  at the adjacent recess. 
   While the second sprocket wheel  553  is operating, the first sprocket wheel  552  rotates, which in turn pushes the spindle  557  circling, further to make the rollers  558  move toward the inclined surface  5594 , and finally get held in between the space between the spindle  557  and inclined surface  5594 . Thus, the first sprocket wheel  552  delivers power through the roller  558  to push the second sprocket wheel  553 . In contrast, while circling in counter-clockwise direction, the spindle  557  pushes rollers  558  into the recesses  5591  (as the imagination line showing). Therefore, the power of the first sprocket wheel  552  can not deliver through the rollers  558 , causing the first sprocket wheel  552  idling. 
   Referring to  FIG. 8 , while the pedal scooter  5  is not used, the steering rod  52  can be bent down to connect with frame  51  for convenient storage. When in use, a user only needs to pull up the steering rod  52  so the pedal scooter  5  can be unfold as showing in  FIG. 4 . Referring to  FIG. 9 , the user holds the steering rod  52  in hand to control the moving direction. Further, the user steps on the pedal  541  with one foot as the interlock state showing in  FIG. 9 and 10 . That is, relying on the reversing power of the elastic body  542  for supporting, the pedal  541  will be pushed upwardly to make the curved rack  551  move up and down to rotate the first sprocket wheel  552 , which in turn pushes the second sprocket wheel  553  to rotate right away. The rotating of first sprocket wheel  552 , which moves the second sprocket wheel  553 , is made possible by the one-way transmission bearing  555  disposed between the two sprocket wheels; the one-way bearing  555  makes the first sprocket wheel  552  rotate the second sprocket wheel  553  in one direction only, not allowing for rotating in a reverse direction, which would counteract the rotating power of second sprocket wheel  553 . As a result, the second sprocket wheel  553  moves the third sprocket wheel  554 , which in turn rotates the wheel  53  as a forwarding power, enhancing the controlling stabilities while the two transmission assemblies  55  are still delivering power. In addition, a user&#39;s weight applied to the pedal repeatedly in operation also achieves the exercising effect. 
   To sum up, the invention makes use of the drive assembly to rotate the two transmission assemblies disposed on the frame; therefore, it could move the wheel rotate more stably than prior arts. Moreover, whenever a user wants to move the scooter forwards, he only needs to step on the drive assembly repeatedly to rotate the transmission assemblies for advancing the scooter, also achieving an exercising effect. 
   While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.