look here.. <A HREF="http://www.freshpatents.com/Upflow-or-downflow-separator-or-shaker-with-piezoelectric-or-electromagnetic-vibrator-dt20060601ptan20060113220.php" target="_blank">http://www.freshpatents.com/Upflow-or-downflow-separator-or-shaker-with-piezoelectric-or-electromagn...</A>