A disposable plastic film liner for an animal litter box is improved by having an opening in the liner, at about the center thereof, which communicates with a collapsible pocket adapted to lie flat beneath the liner when in use lining the inside of the litter box. As the liner is lifted out of the box...http://www.google.es/patents/US4279217?utm_source=gb-gplus-sharePatente US4279217 - Liner for a litter box
