Fluid driven reciprocating pump

Claim 1

A fluid-driven reciprocating pump, comprising: a housing defining a pair of expansible chambers each containing a displaceable member movable to expand and contract the respective chamber, the movable member in at least one of the expansible chambers being a flexible diaphragm; conducting means conducting the material to be pumped to the flexible diaphragm chamber so as to be pumped upon the expansion and contraction of the chamber; a reciprocating rod connecting the flexible diaphragm of the one chamber so that they move in unison; a main valve having a driving fluid inlet, a driving fluid outlet, a connection to said pair of expansible chambers, and a piston movable from a first position effecting communication between the fluid inlet and the pair of chambers to introduce the driving fluid into the chambers, to a second position effecting communication between the chambers and the fluid outlet to discharge the fluid from the chambers; a pilot valve having a movable piston and fluid connections to the main valve for controlling the position of the piston of the main valve; and operating means carried by the reciprocating rod engageable with the piston of the pilot valve for controlling the connections between the pilot valve and main valve, and thereby the fluid connections from the main valve to the pair of expansible chambers, to effect an expansion and contraction of the diaphragm chamber; said conducting means comprising an inlet one-way valve and an outlet one-way valve leading to and from the flexible diaphragm chamber; said inlet one-way valve comprising a housing formed with a fluid chamber therein, the chamber having an inlet and an outlet; a flexible diaphragm disposed within said chamber and dividing same into a fluid inlet compartment containing the inlet and a fluid outlet compartment containing the outlet; an annular rib engageable with the center of one face of the diaphragm, the periphery of the diaphragm including a plurality of openings establishing communication between the two compartments, whereby fluid flow from the inlet direction is permitted through said openings by the diaphragm being flexed out of engagement with the annular rib, whereas fluid flow in the reverse direction is prevented by the diaphragm being flexed into engagement with the annular rib.