Abstract: The invention is directed to a concrete distribution system for transportable concrete and includes a concrete conveying pipe line of several pipe sections and a pipe line carrier boom of several carrier boom segments. The concrete distribution system is so configured that it can be conveniently used in spatially limited construction sites such as tunnels. This is achieved in that pipe sections (6, 8) are connected to corresponding ones of the carrier boom segments (4, 5). The pipe sections are telescopically engaged with each other and the boom; segments are likewise telescopically engaged with each other. The pipe sections and boom segments are extended and retracted in tandem.

Abstract: The invention is directed to a concrete distributor system which includes a concrete delivery pump, a connecting delivery conduit leading to a multi-part concrete distributor mast and a concrete conveying conduit integrated with the concrete distributor mast and connected to the connecting delivery conduit. The pump imparts pulse-like movements to the concrete and a pipe damper is mounted into one of the conduits to attenuate the pulse-like movements of the concrete as the concrete flows through the conduits.

Abstract: The invention is directed to a concrete placing boom assembly for use with two trucks. The assembly includes a base frame and a rotatable turret rotatably mounted on the base frame. A foldable boom is pivotally connected to the turret and includes a plurality of boom arms articulately connected one with the other so as to be unfoldable to define an extended boom and foldable to define a stack. The foldable boom is separable at a separation location into two sections transportable on respective ones of the trucks. The assembly of the invention makes it unnecessary to provide auxiliary assembly apparatus for coupling the two sections together.

Abstract: The invention is directed to a selfpriming centrifugal pump having a symmetrical annular guide channel with a centrally mounted cover disc. A pair of guide ribs improve the loading of the impeller and increase the capacity for drawing air by suction. The guide rib pair is mounted in the annular guide channel. Each guide rib includes an injection rib and a separation rib. The ribs preferably have a width corresponding to the width of the annular guide channel and are arranged on a secant drawn through the circular peripheral band defined by the outer tips of the vanes of the impeller as the latter rotates.

Abstract: The invention concerns a reciprocating pump whose plunger (10) is connected with a plunger rod (12) that runs in a stuffing box (13) coordinated with the pump cylinder (9) cap and is reciprocated hydraulically, where the cylindrical walls of the pump cylinder (9) are provided, over their entire length, with flow-through openings for a cooling medium passing through them, and the flow-through openings in the cylindrical walls of the pump cylinder (9) are connected to a coolant circuit.

Abstract: A control arrangement for hydraulic drives for driving piston pumps includes a control piston which is switchable between its end positions. The control piston has reciprocably effective longitudinally-extending flow restrictors connected into the power lines of the hydraulic drive and the control valves corresponding to each flow restrictor are provided with a pressure balancer. The direction of flow of the hydraulic fluid is the same through all flow restrictors in all switching positions of the control piston. The pressure balancer is controlled by the drop in pressure across the flow restrictor corresponding thereto. The outlet of the control valve for the hydraulic fluid flowing to the hydraulic drive and the inlet for the hydraulic fluid flowing away from the hydraulic drive are connected together at a common connecting terminal of the hydraulic drive.

Abstract: The invention concerns a reciprocating pump for liquid substances, specifically such contaminated by solids. To render such a reciprocating pump self-cleaning, it is suggested to arrange the intake chamber (7), pressure chamber (2), and the pressure chamber (8) side by side in a horizontal or only slightly declining plane, to arrange the check valves (9, 10, 11, 12) side by side in the same horizontal or slightly declining plane, and to have the pressure socket (20) empty on the bottom side of the pressure chamber. In addition, the intake socket (19) empties suitably from below, vertically or at least steeply rising, into the intake chamber. This design ensures that the paths within the pump extend essentially horizontally or only slightly upwardly, so that any solid particles which have proceeded into the pump housing can be carried out of the pump again.