A material mover includes substantially rectangular top and bottom sheets connected to perimeter sidewalls defining at least one chamber. The bottom sheet is perforated with orifices at least in a central portion and has a greater width than that of the top sheet at least in middle and lower regions...http://www.google.fr/patents/US7725963?utm_source=gb-gplus-shareBrevet US7725963 - Material mover having a fluid film reservoir
