Abstract: A membrane pump has a housing which includes a pump head provided with an internal recess. The pump head is further provided with an inlet opening and an outlet opening which communicate with the recess and are disposed next to one another near an edge of the housing. A membrane extends across the recess and is clamped at its edges by the housing. The membrane and recess together define a pumping chamber. A segment of the membrane is held stationary against the pump head by a clamping finger and forms a seal with the pump head. The seal extends radially between the inlet and outlet openings from the periphery of the pumping chamber to its center. A drive successively urges circumferrentially successive segments of the unconfined part of the membrane into sealing engagement with the pump head to thus direct fluid from the inlet opening to the outlet opening.

Abstract: A peristaltic pump wherein an annular internal surface of the housing and a sleeve-like annular section of an elastically deformable diaphragm define an annular pumping chamber which communicates with the fluid-admitting inlet and with the fluid-discharging outlet of the housing. The diaphragm is provided with an extension which projects radially outwardly from the sleeve-like section and is partially anchored in a socket of the housing. A weakened portion of the extension between the anchored portion and the sleeve-like section is received in a compartment between the inlet and outlet of the housing and is provided with one or more empty or fluid-filled cavities, with one or more recesses, with one or more holes and/or other elasticity enhancing features to ensure that the resistance of the sleeve-like section to deformation will be uniform in each of its parts including that which is integral with the extension.