US Patent 7462136 Elliptic motion exercise machine

An elliptic motion exercise machine includes a frame, on which a reciprocating motion mechanism, a circular motion mechanism and two linking members are provided. Two parallelogram linkage mechanisms are movably mounted on the frame and connected to the linking members. Two foot panels are fixed on the parallelogram linkage mechanisms respectively. The parallelogram linkage mechanisms keep the foot panels in fixed slops in the entire motion, such that when an user stands feet on the foot panels and exerts the foot panels, toes of user's feet moves in a speed that is substantially identical to that of use's heels.