US Patent 7373872 Diaphragm pump

A diaphragm pump (1) is provided with an annular working chamber (6) and an annular diaphragm (3), which is fixed on its outer peripheral region (12) and on its inner edge region (13). The inner and the outer diaphragm fixing points are stationary relative to each other, and a drive element (8) connected to a pump drive for deflection of the annular diaphragm (3) contacts between the outer and inner fixing points. The drive element (8) is formed facing the diaphragm with a sleeve or ring shape with a diameter corresponding approximately to the annular working chamber (6) and contacts with one of its annular ends perpendicular to the diaphragm plane on the side of the annular diaphragm (3) facing the pump drive for deflection and for transmission of a back-and-forth movement to the annular diaphragm (3). A quick-running diaphragm fluid pump is created, for which a combination of high stroke count for simultaneously low pump capacities is provided and which nevertheless is structurally simple and stable in design.