Roller skates each comprised of a base with rollers secured therein and a foot support pivotally secured thereto to pivot around the axle of the front roller, a foot propulsion drive having a spring-loaded flexible cable connected by one end thereof via an overrunning clutch to one of the rollers and...http://www.google.co.uk/patents/US4396204?utm_source=gb-gplus-sharePatent US4396204 - Roller skates
