Leg exercise machine

Abstract

A leg exercise machine includes a frame and a swinging mechanism. The swinging mechanism includes two parallel tubes, four swinging rods and two pedals. The tubes are supported on the frame. Each of the pedals is connected to two corresponding ones of the swinging rods. Each of the universal joints connects a corresponding end of a corresponding one of the tubes to an upper end of a corresponding one of the swinging rods.

1 . A leg exercise machine comprising:
 a frame; and   a swinging mechanism comprising:
 two parallel tubes supported on the frame; 
 four swinging rods; 
 two pedals each connected to two corresponding ones of the swinging rods; and 
 four universal joints each for connecting a corresponding end of a corresponding one of the tubes to an upper end of a corresponding one of the swinging rods. 
   
     
     
         2 . The leg exercise machine according to  claim 1 , wherein each of the universal joints comprises:
 a shaft rotationally inserted in the corresponding tube; and   a ball comprising:
 a semi-spherical shell connected to the shaft; 
 a semi-spherical cover pivotally connected to the semi-spherical shell; and 
 an axle rotationally inserted in the semi-spherical shell, wherein the axle extends perpendicularly to the shaft. 
   
     
     
         3 . The leg exercise machine according to  claim 2 , wherein each of the universal joints comprises a bearing formed on an internal face of the semi-spherical shell, wherein the axle is rotationally supported on the bearing. 
     
     
         4 . The leg exercise machine according to  claim 5 , wherein each of the universal joints further comprises at least one clip for keeping the axle on the bearing. 
     
     
         5 . The leg exercise machine according to  claim 1 , wherein the frame comprises two struts pivotally connected to each other. 
     
     
         6 . The leg exercise machine according to  claim 3 , wherein the frame further comprises two crossbars each connected to a lower end of a corresponding one of the struts. 
     
     
         7 . The leg exercise machine according to  claim 4 , wherein the frame further comprises four anti-skid pads each connected to a corresponding end of a corresponding one of the crossbars. 
     
     
         8 . The leg exercise machine according to  claim 3 , wherein the frame further comprises:
 a U-shaped element for holding one of the struts; and   a pivot for connecting the U-shaped element to one of the remaining strut so that the struts are movable between an opened position and a closed position.   
     
     
         9 . The leg exercise machine according to  claim 6 , wherein the U-shaped element comprises at least one adjustment aperture located below the pivot, wherein the frame further comprises a pin inserted in the adjustment aperture to keep the struts at a desired position relative to each other.