Patent ID: 8360750
Filing Date: 2013-01-29
Classification: F04B

Abstract:
1. A pump device comprising: a first diaphragm pump head having two fluid delivery chambers and two diaphragm control chambers separated by two diaphragms associated therewith; a second diaphragm pump head for driving the first diaphragm pump head, the second pump head having two additional fluid delivery chambers and two additional diaphragm control chambers separated by two associated additional diaphragms; wherein each of the two diaphragm control chambers are separately coupled to one of the two additional fluid delivery chambers to form two separate closed hydraulic couplings between the first diaphragm pump head and the second diaphragm pump head, the closed hydraulic couplings using control fluids which have water or oil; a double-acting piston situated in the second diaphragm pump head and defining a single piston head that simultaneously acts upon both of the two associated diaphragm control chambers to expand one of the two associated additional diaphragms while contracting the other of the two associated additional diaphragms, the expansion of one of the two associated additional diaphragms driving the control fluid from one of the two additional fluid delivery chambers into one of the two diaphragm control chambers via the closed hydraulic couplings to expand one of the two diaphragms and displace a volume in one of the fluid delivery chambers; and a refilling valve being connected to each of the diaphragm control chambers, and, using the refilling valves, the diaphragm control chambers being impinged temporarily, during a refilling procedure, which is controlled by a position of the two associated additional diaphragms, by a diaphragm control pressure, which approximately corresponds to a fluid pressure at an inlet of the fluid delivery chambers of the first diaphragm pump head.