Roller skates having a shoe or boot supported by a central support beam. The boot has an inside and outside corresponding to the inside and the outside of a user's foot to which it is designed to be removably attached. Each skate also has a first and second group of wheels in longitudinal alignment with...http://www.google.co.uk/patents/US5251920?utm_source=gb-gplus-sharePatent US5251920 - Beam off-set roller skate
