US Patent 8360475 Roller skis or boards

The present invention relates to a roller ski or board, said ski or board providing in-line central rollers, centrally provided on the ski or board body, and two pairs of additional rollers, respectively a front pair and a rear pair, said pair of rollers being raised with respect to the ground on which ski or board rests when the same ski or board is substantially parallel with respect to the ground, and contacting the same ground when ski or board is inclined, each one of the additional rollers is coupled with the ski or board by a support system comprising a fork, having one end coupled with the roller and the other one faced toward the ski or board, between the end of the fork faced toward the ski or board and the same ski or board being provided with a resilient element.