Abstract: A fluid driven reciprocating pump comprises a pair of heads each containing a displaceable member defining a drive chamber and a pump chamber on opposite sides of the diaphragm in one head, and a drive chamber and an inactive chamber on opposite sides of the diaphragm in the other head. A mechanical coupling connects the two displaceable members for reciprocation together; and a control valve assembly connects the drive chambers of both heads to a source of pressurized fluid for driving them through forward strokes, a spring driving the heads through return strokes.

Abstract: A fluid-driven reciprocating pump comprises a pair of pumping heads each containing a displaceable member defining a driving chamber and a pumping chamber, a mechanical connection coupling the two displaceable members for reciprocation together, and means for connecting the driving chamber of one pumping head to a source of pressurized fluid and the pumping chamber of that pumping head to a source of material to be pumped. The pump further includes means for connecting the driving chamber of the other pumping head to a source of pressurized fluid and for selectively connecting the pumping chamber of the other pumping head either to a source of material to be pumped to produce a double-action pumping operation wherein the material is pumped during both reciprocations of the displaceable members, or to the source of pressurized fluid to produce a single-action pumping operation wherein the material is pumped during only one of the two reciprocations of the displaceable members.

Abstract: A fluid driven reciprocating pump is described, particularly for use in feeding fertilizer solution to an irrigating water line, the pump being driven solely by the pressurized water in the supply line and requiring no electricity or other power source for either driving or controlling the pump. The described pump includes a pair of flexible diaphragms defining a pair of expansible chambers, and a reciprocating rod connecting the diaphragms to each other so that they move in unison. A main valve supplies pressurized water to the expansible chambers, and a pilot valve controlled by operator elements carried by the reciprocating rod controls the main valve connections to the pair of expansible chambers such as to effect an expansion and contraction of the chambers.