Structure for a stepper

Abstract

The present invention discloses an improved structure for a stepper, particularly a stepper having a restoring device, wherein an inertial gas together with hydraulic oil is filled into the hydraulic cylinder of a stepper. As the outer shell of the atom of the inertial gas is saturated with electrons, the inertial gas will be very stable in the hydraulic cylinder. When a force is applied to the piston rod of the stepper, the piston will be pushed forward to compress the inertial gas and the hydraulic oil. When the force acting on the piston is released, the inertial gas will expand, which will create a restoring force to push the piston back to the original position.

1 . An improved structure for a stepper, comprising: 
 an outer cylinder;    an inner cylinder, installed inside said outer cylinder;    a piston assembly, further comprising a piston and a piston rod, and installed inside said inner cylinder, wherein said piston further comprises gaskets, O-rings, and a nut, and said piston is installed on the internal end of said piston rod;    a seat, installed on one end of said inner cylinder;    a bearing, installed inside said outer cylinder, and engaged with the other end of said inner cylinder;    a joint seat, installed inside said outer cylinder, firmly contacting said seat installed on one end of said inner cylinder; and    connecting elements, separately installed to the external end of said outer cylinder and the external end of said piston rod; and    characterized in that a stable gas together with hydraulic oil is filled into the hydraulic cylinder to create a restoring force while the force acting on said piston is released.    
     
     
         2 . The improved structure for a stepper according to  claim 1 , wherein said stable gas is an inertial gas.  
     
     
         3 . The improved structure for a stepper according to  claim 2 , wherein said inertial gas is nitrogen.  
     
     
         4 . The improved structure for a stepper according to  claim 2 , wherein said inertial gas is helium.  
     
     
         5 . The improved structure for a stepper according to  claim 1 , wherein said hydraulic oil is a machine oil.  
     
     
         6 . The improved structure for a stepper according to  claim 5 , wherein said hydraulic oil is a mineral-oil based one.  
     
     
         7 . The improved structure for a stepper according to  claim 5 , wherein said hydraulic oil is a synthetic oil.  
     
     
         8 . The improved structure for a stepper according to  claim 1 , wherein multiple notches are formed on said seat.  
     
     
         9 . The improved structure for a stepper according to  claim 8 , wherein multiple holes are formed on said seat.  
     
     
         10 . The improved structure for a stepper according to  claim 1 , wherein said bearing and said joint seat are fixedly installed to said outer cylinder in cooperation with O-rings.  
     
     
         11 . The improved structure for a stepper according to  claim 10 , wherein said bearing and said joint seat are fixedly installed to said outer cylinder by roll welding.  
     
     
         12 . The improved structure for a stepper according to  claim 1 , wherein said connecting elements have holes.  
     
     
         13 . The improved structure for a stepper according to  claim 1 , wherein said outer cylinder and said inner cylinder are cast in carbon steel.  
     
     
         14 . The improved structure for a stepper according to  claim 7 , wherein said outer cylinder and said inner cylinder are cast in an aluminum alloy.  
     
     
         15 . The improved structure for a stepper according to  claim 1 , wherein said piston rod is chromium-plated.  
     
     
         16 . The improved structure for a stepper according to  claim 1 , wherein said gasket is made of Teflon.  
     
     
         17 . The improved structure for a stepper according to  claim 1 , wherein said O-ring is made of rubber.