The present invention aims at improving pool cleaners. The improved pool cleaners utilize toroidal vortex technology to provide efficient fluid flow in a sealed system. The sealed system prevents dirt from escaping into surrounding fluid and retains kinetic energy of the flowing fluid. The present invention...http://www.google.es/patents/US6811687?utm_source=gb-gplus-sharePatente US6811687 - Vortex pool cleaner
