Patent ID: 6276907
Filing Date: 2001-08-21
Classification: F04B

Abstract:
A diaphragm pump apparatus comprising:a. a first chamber that accommodates and dispenses a fluid to be pumped;b. a second chamber that accommodates a drive fluid;c. a diaphragm that separates the first chamber from the second chamber and has a first chamber side and a second chamber side, the diaphragm including an outer perimeter mounting region, a thin inner perimeter flexible region, and a curvedly contoured central drive region having a stem on the second chamber side and a central pumping surface on the first chamber side, the diaphragm movable from a first limit farthest away from the first chamber to a second limit closest to the first chamber;d. a piston located at least partially within the second chamber driven by a motor mounted eccentric that causes reciprocating movement of the piston, the piston movement resulting in corresponding drive fluid movement within the second chamber; ande. a backing ring mounted within the second chamber adjacent to the diaphragm defining a central opening through which the stem of central drive region of the diaphragm passes, the backing ring including:i) a plurality of holes passing through the backing ring, the plurality of holes configured to distribute the drive fluid across the flexible region and the central drive region of the diaphragm after the drive fluid is driven by the drive fluid movement within the second chamber through the plurality of holes, at least some of the plurality of holes positioned within the backing ring opposite the flexible region of the diaphragm; andii) a diaphragm mating surface curvedly contoured to mate with the second chamber side of the diaphragm,such that pressure formed by the drive fluid passing through the plurality or holes into a drive fluid volume located between the diaphragm mating surface of the backing ring and the second chamber side of the diaphragm drives the diaphragm from first the limit toward the first chamber while flexing the flexible region of the diaphragm toward the first chamber from the outer perimeter inward toward the central pumping surface in a rolling manner, the diaphragm moving substantially all of the fluid to be pumped adjacent the diaphragm within the first chamber radially inward toward the central pumping surface and then out of the first chamber when the diaphragm reaches the second limit.