A cycling mechanism consisting of foot pedals attached to rotatable cranks, in which the crank axes are independently connected to the machine frame in a movable manner such that in addition to each of cranks being rotatable about their respective axis, the crank axes are simultaneously allowed to translate...http://www.google.co.uk/patents/US5935046?utm_source=gb-gplus-sharePatent US5935046 - Variable motion elliptical exercise machine
