Abstract: A double membrane pump having a casing and a piston rod movably received in the casing, the casing having at least one inlet opening and at least one outlet opening, and a first membrane is arranged at one end of the piston rod and a second membrane is arranged at the other end of the piston rod. The first membrane is arranged in a first chamber of the double membrane pump and the second membrane is arranged in a second chamber. The membranes are designed to separate the chambers into a product chamber and an expansion chamber respectively. The pump has a drive device for bringing about a translational movement of the piston rod. The double membrane pump has a piston rod which is designed to perform a self-regulated, oscillating movement and thus enables simplified control of the membranes.

Abstract: A high pressure double membrane pump has a central housing (3), two cylindrical pump chambers (7,8), a coupling rod (4) which moves back and forth when the pump is in operation and which has a pump piston (9), two membranes which divide each of the pump chambers (7,8) into a product chamber (11,12) and a compressed air chamber (1,2) with changing volumes of which the membranes have a peripherally mounted membrane body (15). In the central area of the membrane body (15) a rigid implant body (17) is embedded which is equipped with a dog (18) which is connected to one end of the coupling rod (4), and a pneumatic control unit for the alternating impinging of compressed air upon the compressed air chambers. In the area of the compressed air chambers (1,2) a rigid supporting ring (20) is pushed onto the dog (18) between the end of the coupling rod (4) and the inner side of the membrane (5).

Abstract: A dual diaphragm pump includes a central housing having a pair of opposed housing surfaces, each surface having a housing diaphragm recess and a pair of housing valve recesses, and a pair of covers, each cover having a surface with a cover diaphragm recess and a pair of cover valve recesses. The covers are mated to the housing so that the diaphragm recesses form a pair of pumping chambers with diaphragms therein, and the valve recesses form valve chambers with check valves therein.