Abstract: A boom construction for truck-mounted concrete pumps has at least a first boom arm and a second boom arm that are articulatedly jointed to each other and that are rotatable relatively to each other about an axis. A drive pivots the boom arms. A piston-cylinder arrangement and a gear transform piston reciprocating movement into rotary movement for boom arm pivoting, said arrangement having first and second pistons that form part of the gear and that interact with outer rings of the gear.

Abstract: A boom construction for truck-mounted concrete pumps has at least a first boom arm and a second boom arm that are articulatedly jointed to each other and that are rotatable relatively to each other about an axis. A drive pivots the boom arms. A piston-cylinder arrangement and a gear transform piston reciprocating movement into rotary movement for boom arm pivoting, said arrangement having first and second pistons that form part of the gear and that interact with outer rings of the gear.

Abstract: In a hydraulic cylinder for a multiple-part mast superstructure comprising at least two mast arms which are connected in an articulated manner and of which one can be pivoted with respect to the other mast arm by the hydraulic cylinder, it is proposed that the base region of the cylinder container is of curved configuration, which cylinder container is closed in the base region on one side in order to accommodate a piston. In this way, the force flux is improved in the walls of the hydraulic cylinder, with the result that manufacturing which uses less material and is correspondingly less expensive is possible, with a simultaneously reduced overall weight. The hydraulic cylinder in accordance with the invention is suitable, in particular, for use with concrete pumps, cranes, lifting platforms and the like or general apparatuses having mast superstructures, in which hydraulic cylinders are used for pivoting.