Abstract: A device for regulating in a practically loss-free manner the pressure and feed volume of a diaphragm pump which is constructed as a hydraulically activatable diplacement pump and is especially suited for feeding a viscous and abrasive or a solids-laden secondary fluid medium. In the device, access is required only to the environment of the primary working fluid medium, and no direct interchanges between the secondary medium being fed and parts of the control device are required. During the pressure phase of the diaphragm pump, a limited quantity of the primary working medium is extracted from a portion of the housing of the device which is in direct and uninterrupted communication with the associated working section, while during the suction phase and in dependence on the overpressure of the primary working fluid medium in the device a compensation is made for the quantity of the primary working fluid medium lost during the pressure phase.

Abstract: An oscillating displacement pump particularly adapted for pumping a viscous and abrasive fluid medium or one loaded with solid particles. The pump includes a connecting space located outside of a displacement unit and directly connecting a suction valve space with a pressure valve space so that the geodetic height of pumped medium increases. The connecting space defines a suction valve side connecting channel and a pressure valve side connecting channel connected at any given time with each other through the displacement unit space independent of the position of the displacement unit. The pumped medium can thus be moved through the pump from the suction valve to the pressure valve without diversion in a separate connecting space reducing abrasive wear on the pump. A number of additional advantageous features of the pump are disclosed.

Abstract: A diaphragm pump especially for pumping viscous and abrasive materials including a spherical housing, the inner portion of which defines a pumping chamber together with a cylindrical hose membrane activated by a pulsating medium. One or more hose membranes surround a support pipe having a circular cross section to prevent compressive strain on the membranes during pumping by deformation of the membrane in the inward direction. In an alternative embodiment, a modulated support tube is provided to permit the diaphragm to flap into the indentations of the support tube in a manner neutral to longitudinal extension. Support rings are provided which permit symmetrical arching of the hose diaphragm during the compression stroke.