A rolling device such as a roller ski or in-line skate that uses a roller of a hard material with the roller mounted to the frame of the roller ski or in-line skate in such a manner that it can be forcibly moved to contact the elastomeric wheel of the roller ski or in-line skate, causing the softer elastomeric...http://www.google.co.uk/patents/US5374071?utm_source=gb-gplus-sharePatent US5374071 - Foot supporting rolling device with speed reducer and brake
