Elevational adjusting device of exercise bicycle

Abstract

An elevational adjusting device is used in an exercise bicycle which has a body capable of standing on the ground. The body is movable by a treading operation. A cushion of the bicycle is adjustable. The elevational adjusting device comprises an outer tube having a hollow inner space and a long hole; an inner tube being installed with a cushion at a top thereof; the inner tube having a plurality of positioning holes which are positioned corresponding to a position of the long hole of the outer tube; a frame seat fixed to the outer tube; and a positioning unit having a post; the positioning unit being positioned to the frame seat; the positioning unit having a buckle bar capable of being buckled to one of the positioning holes of the inner tube; a driving arm; and a cam portion capable of resisting against an wall of the inner tube.

1 . An elevational adjusting device of an exercise bicycle having a body capable of standing on the ground, the body being movable by a treading operation; a cushion of the bicycle being adjustable; the elevational adjusting device comprising: 
 an outer tube having a hollow inner space and a long hole;    an inner tube being installed with a cushion at a top thereof; the inner tube having a plurality of positioning holes which are positioned corresponding to a position of the long hole of the outer tube;    a frame seat fixed to the outer tube; and    a positioning unit having a post; the positioning unit being positioned to the frame seat; the positioning unit having a buckle bar capable of being buckled to one of the positioning holes of the inner tube; a driving arm; and a cam portion capable of resisting against an wall of the inner tube;    wherein by the buckle bar of the positioning unit being buckled to the positioning hole of the inner tube; the inner tube is positioned to the outer tube; the gravitational force of the cushion will make the positioning unit to rotate along the post, so that the cam portion resist against the wall of the inner tube; thereby the inner tube and the outer tube are stably positioned.    
   
   
       2 . The elevational adjusting device of an exercise bicycle as claimed in  claim 1 , wherein the positioning unit has a stopper; and the frame seat has a sleeve for confining the stopper so that the inner tube will not descend unlimitedly due to the wearing of the cam portion of the positioning unit.  
   
   
       3 . The elevational adjusting device of an exercise bicycle as claimed in  claim 1 , wherein a spring is connected between the frame seat and the positioning unit so as to further position the positioning unit.