Abstract: A piston diaphragm pump includes a driving fluid chamber and a driven fluid chamber. A flexible diaphragm separates the fluid chambers from one another. An electric motor drives a reciprocating piston through a crankshaft, and the piston moves in the driving fluid chamber from a forward position to a rearward position on a suction stroke and from the rearward position to the forward position on a pressure stroke. An inlet passage extends between a crankcase and the driving fluid chamber, and a normally closed inlet valve in the inlet passage is opened by a cam on the crankshaft when the piston reaches a predetermined position on its suction stroke. The driving fluid in the driving fluid chamber drives the flexible diaphragm back and forth, and the back and forth movement of the diaphragm pumps the driven fluid into and out of the driven fluid chamber.

Abstract: A device for mixing gases with liquids is disclosed, which is characterized by the use of gas inlet and vent valves of unique construction and highly efficient in operation, and the use of a unique toggle mechanism for opening and closing said valves which consists of a minimum number of parts arranged to form a compact unit. The device further includes a fully enclosed or hollow float which coacts with the valve opening and closing mechanism, and a rigid metallic gas inlet tube which functions as a support for a gas diffuser.