Abstract: A rotary tower crane for construction purposes comprising a non-rotating mast, a boom mounted at the head of the mast by a rotary connection so as to be swingable about the mast axis, a lifting device on the boom consisting of a hoisting rope which can be raised and lowered, and a distributor device for supplying and distributing concrete in the working area of the crane. The distributor device comprises a platform mounted on the mast below the rotary connection, an articulated distribution arm serving as a carrier structure for a concrete conveyor pipe formed in a plurality of sections connected together by ram-actuated connections, and having a rotatable mounting located on the platform. The platform is mounted on the mast by a ram-actuated rotational coupling so that the platform may be swung about an axis parallel to the axis of the crane mast to provide an operational field for the platform which is limited by the extent of swing of the platform on both sides of the crane mast.

Abstract: In a double-cylinder pump for conveying cement, a distribution pipe is pivotally driven into alignment with each of the cylinders in turn. A wearing ring, which provides a seal between the end of the pipe and the cylinders, is mounted so as to be movable with respect to the end of the pipe so as to be able to assimilate wear.

Abstract: In a multi-cylinder pump for conveying concrete, the flow of concrete to and from the cylinders is controlled by a pivot body containing a pressure channel. The pressure channel is bounded by blades, each of which has a blade plate shaped in accordance with the flow of material and sealed to the pump casing wall at its edges. Each blade also has a base whereby it is attached to the pivot body shaft.

Abstract: A distributing valve for twin cylinder pumps for pumping viscous materials such as concrete, has an oscillating body with closing elements, for the suction orifices and pressure orifices for the pump cylinders mounted on a shaft disposed outside the part of the pump casing acted upon by the pump pressure. The closing elements are arranged on the same side of the rotating shaft and a pair of closing elements is provided either for the suction orifices or for the pressure orifices.

Abstract: Apparatus for distributing concrete comprises a jib rotatably mounted on a tower, with a conveyor pipe line mounted on the end thereof so as to be movable about horizontal and vertical axes. The pipe line is formed in several sections which are connected one below the other by pivotal joints with horizontal axes.