A strainer that is used in association with a motor-driven pump that sucks water out of outdoor pits, reservoirs, streams, ponds, and the like, usually for irrigation or watering purposes. The strainer has a cylindrical screen disposed on a spool-like body for rotation substantially about its own axis....http://www.google.fr/patents/US5215656?utm_source=gb-gplus-shareBrevet US5215656 - Rotary self-cleaning strainer
