The present invention is a wobble plate pump typically used in a reverse osmosis water purification system. The pump has a piston that is coupled to a wobble plate by a rocker arm. The piston has a stem which snaps into a corresponding sleeve of a diaphragm. The diaphragm is attached to the rocker arm...http://www.google.ca/patents/US5626464?utm_source=gb-gplus-sharePatent US5626464 - Wobble plate pump
