Pneumatic ab wheel

Abstract

A pneumatic ab wheel includes shaft having a middle section and two holding sections, a rotation assembly pivotally connected to the middle section of the shaft and performing a rotational movement on the shaft, and a wheel provided around the rotation assembly to drive the rotation assembly to perform the rotational movement on the shaft and to roll on a surface while in contact with the surface so as to generate a frictional force. The wheel is filled therein with at least one gas to form a pneumatic pressure in the wheel. When the pneumatic pressure in the wheel is adjusted, the frictional force between the wheel and the surface is changed.

What is claimed is: 
     
         1 . A pneumatic ab wheel, comprising:
 a shaft, having a middle section, and two holding sections respectively extending from the middle section and towards opposite directions;   a rotation assembly, pivotally connected to the middle section of the shaft, performing a rotational movement on the shaft, having a limiting area; and   a wheel, provided around the limiting area of the rotation assembly to drive the rotation assembly to perform the rotational movement on the shaft, and to perform rolling while in contact with a surface to generate a frictional force;   wherein, the wheel is filled therein with at least one gas so as to form a pneumatic pressure in the wheel, and the frictional force between the wheel and the surface is changed when the pneumatic pressure in the wheel is adjusted.   
     
     
         2 . The pneumatic ab wheel of  claim 1 , wherein each of the two holding sections is sleeved by a grip. 
     
     
         3 . The pneumatic ab wheel of  claim 2 , wherein each of the two grips comprises an anti-slip region. 
     
     
         4 . The pneumatic ab wheel of  claim 1 , wherein the rotation assembly comprises a first pivotal connection member, and a second pivotal connection member pivotally assembled with the first pivotal connection member. 
     
     
         5 . The pneumatic ab wheel of  claim 4 , wherein the first pivotal connection member comprises a first pivotal connection body and a first side cover covering one side of the first pivotal connection body, and the second pivotal connection member comprises a second pivotal connection body and a second side cover covering one side of the second pivotal connection body. 
     
     
         6 . The pneumatic ab wheel of  claim 5 , wherein the first pivotal connection body and the second pivotal connection body are located between the first side cover and the second side cover. 
     
     
         7 . The pneumatic ab wheel of  claim 1 , wherein the wheel comprises an air hole, through which the pneumatic pressure in the wheel is adjusted.