Abstract: A stroke drive, particularly for displacement piston pumps, has a first eccentric (8) on which a second eccentric (9) is mounted. A push rod bearing (10) is connected to the second eccentric (9). The eccentrics (8, 9) are connected to each other by way of an intermediate drive (17) which conveys a synchronous rotation to the eccentrics. An adjusting device (16) serves to change the relative position of the eccentricities (e1, e2) of the eccentrics (8,9) relative to each other. In this manner the length of the stroke is steplessly adjustable from a maximal value to a minimal value.

Abstract: The invention relates to an adjustable stroke piston machine assembly wherein the stroke is adjustable steplessly from zero to full displacement. Two connecting rods are provided and a pivotal joint between the rods is guided by an arc shape path of a guide member. The guide member is pivotally adjustable to vary the position of the arc shaped path relative to the piston and thereby vary the stroke of the piston.

Abstract: The invention relates to a dirt filter for water pipes of the type used for carrying water for household and industrial use. The filter defines inlet and outlet chambers with an apertured dividing wall therebetween. An upper lid and a lower dirt collecting container and attached with threaded connections to the housing. A filter insert is disposed between the lid and the dividing wall and the insert has a carrier with upper and lower cylinder rings which respectively engage the lid and the chamber dividing wall. The interior of the filter has fluid communication with the inlet chamber through the opening in the chamber dividing wall. An annular, cup shaped insert keeps the flow in the inlet chamber away from the interior of the dirt collecting container but permits the drop of dirt into this container.

Abstract: The invention relates to apparatus for regulating the pH value, or other similar values, of a solution. The apparatus includes an actual value transmitter, a desired value transmitter, a regulator controlled by the two transmitters, and a servo unit controlled by the regulator for adding a measured amount of additive to the solution. The servo unit includes a pulse driven metering pump to provide the supply of additive. The applied pulse frequency has a logarithmic relationship to the control signal derived from an error signal which makes possible exact regulation corresponding to the logarithmetic relationship between the pH value and the concentration of additive introduced into the solution.

Abstract: Apparatus for pumping the eluent liquid through a chromatograph column is provided in the form of an electromagnetic metering pump, the outlet of which is provided with a pulsation damping device in the form of a sealed chamber having a resiliently loaded elastic wall. Considerable control of operation is obtainable by adjustment of the resilient loading and the operation of the pump (speed and stroke length). The chamber may be fitted with a pressure gauge having a closable outlet to atmosphere for purging purposes. Effective chromatographic separation of mixtures is obtainable at low equipment costs.