An apparatus for purifying water, comprising a funnel-shaped member, a sleeve formed integrally with said member, a cup-shaped insert having a cylindrical wall arranged within the sleeve, screen-like closure members at upper and lower ends of the cylindrical wall of the insert, defining an accommodation...http://www.google.fr/patents/US4306971?utm_source=gb-gplus-shareBrevet US4306971 - Water purifying apparatus
