Abstract: The present invention relates to a viscous material pump. According to the invention, a pressure sensor is associated with the hydraulic drive cylinder of the fixed displacement pump for generating a pressure signal when a first sudden pressure increase occurs after the drive piston moves out of its end position. The volume subsequently displaced by the conveying piston corresponds to the actual delivery volume during the pumping stroke. A processor calculates the actual delivery volume for each pumping stroke using the ratio between the stroke time, as defined by the occurrence of the pressure peak and the maximum available conveying volume of the cylinder, as defined by the stroke time the piston needs to move from its first to its second end position. The present invention further provides for adjusting the supply volume of a supply means discharging the material to the viscous material pump.

Abstract: An apparatus for controlling the hydraulic circuit of a piston diaphragm pump, having at least a pump diaphragm alternatingly subjected to the presure or the suction stroke of a piston operatingly connected to driving means, the apparatus comprising control means changing the amount of hydraulic medium displaced by the piston in dependence of a power demand or the like. A displacement sensor is associated with one side of the diaphragm facing the hydraulic medium, the sensor measuring the stroke travel of the diaphragm and generating a corresponding stroke travel signal which is transmitted to control means, the control means including storage means storing predetermined stroke values and/or stroke value ranges for predetermined hydraulic power values of the pump.

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.