Abstract: A control device for a diaphragm pump to feed a filter press or similar user unit comprising a three-phase electric driving motor for the pump which is connected to a supply main via a variable-frequency converter, which frequency converter has an analogue output at which a signal will appear which corresponds to the respective motor torque, a standard r.p.m. set-point adjuster to the input of which the actual signal is provided via an inverter and in which a graph is stored which produces an interdependences between the motor torque and the speed such that if the actual-signal rates are small the graph for the speed runs along a constant maximum value and if a preset rate is reached for the actual signal it gradually declines to a minimum value, and an attenuation member for the actual signal.

Abstract: A solid material pump comprising a pump housing, a pair of parallel pump cylinders driven by hydraulic cylinders and each connected to a pump chamber, a slurry feed device which communicates via inlet valves with inlet valve chambers each of which communicates with a pump chamber, the axes of valve cylinders for actuating the inlet valves extending in parallel and spaced relationship to the axes of the pump cylinders and the inlet openings being provided at the pump housing opposite to the pump cylinder whereby the sucked-in flow is deflected twice, further comprising outlet valve chambers adapted to communicate via outlet valves each with a pump chamber and connected to a common outlet conduit, with the valve cylinders for actuating the outlet valves being connected to the pump housing on the side opposite to the inlet valve cylinders and their axes extending in parallel and spaced relationship to the axes of the pump cylinders and the inlet valve cylinders.

Abstract: The invention relates to a double diaphragm pump having flexible diaphragms disposed in displacement spaces and connected and mechanically coupled to piston rods, the displacement spaces being communicated via check valves to a suction manifold on the one hand and to a pressure manifold on the other hand, wherein each diaphragm is connected to a piston rod, which piston rods extend coaxially and are mounted on opposite sides to a guide frame having at least one lineal guide for a guide block which rotatably mounts a crank pin of a crankshaft.