Crankshaft for elliptical exercise machine

Abstract

A crankshaft is mounted on a frame of an elliptical exercise machine and is pivotally connected with a link bar of the elliptical exercise machine, including a linking member, a foot support bar, and a slide member. The linking member is pivotally connected with the link bar and has a pivoting portion. The foot support bar is mounted on a guide rail of the elliptical exercise machine and has a pivoting part. The slide member is mounted between the pivoting portion of the linking member and the pivoting part of the foot support bar to be mounted in the pivoting part of the foot support bar, such that the linking member, the foot support bar, and the slide member are pivotally connected with respect to one another.

What is claimed is:  
     
         1 . A crankshaft for an elliptical exercise machine, said elliptical exercise machine having a frame, a stanchion and a driving wheel both mounted in front of said frame, a guide rail mounted behind said frame, a link bar connected with an axle of said driving wheel to be synchronously moved together with said driving wheel, said crankshaft being pivotally connected with a distal end of said link bar and comprising: 
 a linking member having a head portion and a body portion, said head portion being pivotally connected with said link bar, said body portion having a pivoting portion;    a foot support bar having a pivoting part at a front section thereof and mounted on said guide rail at a distal end thereof; and    a slide member mounted between said pivoting portion of said linking member and said pivoting part of said foot support bar to be mounted in said pivoting part, whereby said linking member, said foot support bar, and said slide member are pivotally connected with respect to one another.    
     
     
         2 . The crankshaft as defined in  claim 1 , wherein said linking member further comprises a pivot hole running through said head portion for pivotally connected with said link bar of said elliptical exercise machine.  
     
     
         3 . The crankshaft as defined in  claim 1 , wherein said foot support bar further comprises a pedal for the user's treading.  
     
     
         4 . The crankshaft as defined in  claim 1 , wherein said foot support bar further comprises a pulley disposed at a distal end thereof and bends downwards at a rear section thereof to enable said pulley to be slidably mounted on said guide rail corresponding to said pulley.  
     
     
         5 . The crankshaft as defined in  claim 1 , wherein said slide member comprises a through hole axially running therethrough, said through hole having an inner diameter slightly larger than an outer diameter of said linking member, said slide member having an outer diameter slightly smaller than an inner diameter of said pivoting part of said foot support bar.  
     
     
         6 . The crankshaft as defined in  claim 1 , wherein said linking member, said foot support bar, and said slide member are pivotally connected with one another by inserting a bolt therethrough.  
     
     
         7 . The crankshaft as defined in  claim 1 , wherein said foot support bar has two front corners at a front end thereof, said front end of said foot support bar and said head portion of said linking member are provided with a gap formed therebetween, whereby while said foot support bar pivots, said two front corners of said foot support bar engage respectively against an outer periphery of said linking member to confine a pivoting range of said support bar.