, or coaxial of, the impeller into the housing and an outlet from the periphery of the chamber,...http://www.google.com/patents/US4768920?utm_source=gb-gplus-sharePatent US4768920 - Method for pumping fragile or other articles in a liquid mediumAdvanced Patent SearchPublication numberUS4768920 APublication typeGrantApplication numberUS 06/728,314Publication dateSep 6, 1988Filing dateApr 29, 1985Pr