Abstract: The invention relates to a hydraulically actuated dual-cylinder piston pump (1), with a first differential cylinder (22), with a head-end chamber (51) and a rod-end chamber (53), which actuates a first delivery piston (4) via a first piston rod (6), and also with a second differential cylinder (23), with a head-end chamber (52) and a rod-end chamber (54), which actuates a second delivery piston (5) via a second piston rod (7), and with a switching device (14) which by switching the hydraulic oil flow to the chambers (51, 52, 53, 54) of the differential cylinders (22, 23) establishes a head-end or rod-end operating mode of the dual-cylinder piston pump (1), wherein the switching device (14) is arranged on the bottoms (48, 49) of the head-end chambers (51, 52) of the differential cylinders (22, 23) as a bridge-forming connection between the differential cylinders (22, 23).

Abstract: A large manipulator includes a chassis, at least two front support arms, and at least two rear support arms. The support arms are coupled to corresponding extendable support legs that are each coupled to the chassis and that are each configured to be extended between a travel position and a support position. The large manipulator further includes a mast arm with a turntable coupled to the chassis. An operating range of the mast arm is dependent upon the support positions of the extendable support arms. The large manipulator further includes a computer with a monitor and a program-controlled positioning aid. The positioning aid is configured to generate a graphical representation of surrounding image data on the monitor. The operating range of the mast arm is visualized in the graphical representation.

Abstract: An electrohydraulic control circuit for driving a hydraulically actuated actuating element (5, 6), by means of which a segment (5.3) of a manipulator, in particular of a large manipulator for truck-mounted concrete pumps, can be adjusted in terms of its orientation, wherein there are provided an electrically driven first valve (2.4), which is connected to hydraulic working lines of the actuating element (5.6) for the drive thereof, and leak-free check valves (2.5, 2.6) provided in the working lines of the actuating element (5.6), which valves are arranged on the actuating element (5.6) or on the segment (5.3) associated with this actuating element (5.6) and can be released for the normal operation of the actuating element (5.6), wherein the release of the check valves (2.5, 2.6) is driven by an electronic control unit (ECU) separate from the first valve (2.4) and the check valves (2.5, 2.6).

Abstract: A large manipulator includes a chassis, at least two front support arms, and at least two rear support arms. The support arms are coupled to corresponding extendable support legs that are each coupled to the chassis and that are each configured to be extended between a travel position and a support position. The large manipulator further includes a mast arm with a turntable coupled to the chassis. An operating range of the mast arm is dependent upon the support positions of the extendable support arms. The large manipulator further includes a computer with a monitor and a program-controlled positioning aid. The positioning aid is configured to generate a graphical representation of surrounding image data on the monitor. The operating range of the mast arm is visualized in the graphical representation.

Abstract: A switch-over apparatus for a thick-matter pump includes a housing that forms a pre-fill vessel, which has first and second inlet/outlet openings and an outlet opening positioned on opposite sides of the housing. The apparatus further includes a pivot body positioned within the housing and that forms a duct. The duct includes a duct inlet configured to pivot between the first and second inlet/outlet openings and includes a duct outlet configured to align with outlet opening. The pivot body forms at least one seal chamber adjacent the duct inlet or duct outlet. The apparatus further includes an elastic seal positioned within the seal chamber and includes a support strip positioned within the seal chamber between the elastic seal and the pivot body. The seal strip forms first and second oblique-cut ends.

Abstract: An electrohydraulic control circuit for driving a hydraulically actuated actuating element (5, 6), by means of which a segment (5.3) of a manipulator, in particular of a large manipulator for truck-mounted concrete pumps, can be adjusted in terms of its orientation, wherein there are provided an electrically driven first valve (2.4), which is connected to hydraulic working lines of the actuating element (5.6) for the drive thereof, and leak-free check valves (2.5, 2.6) provided in the working lines of the actuating element (5.6), which valves are arranged on the actuating element (5.6) or on the segment (5.3) associated with this actuating element (5.6) and can be released for the normal operation of the actuating element (5.6), wherein the release of the check valves (2.5, 2.6) is driven by an electronic control unit (ECU) separate from the first valve (2.4) and the check valves (2.5, 2.6).

Abstract: The invention relates to a method for operating a drive device for a dual-cylinder slurry pump and to a drive device for a dual-cylinder slurry pump, comprising two drive cylinders that are actuated by means of a fluid (1, 2), said cylinders alternately charging a common delivery line with slurry, in particular concrete, via a pipe switch (RW), in particular indirectly by means of driven delivery cylinders (FR, FL). According to the invention, the pipe switch is likewise actuated by means of a fluid using an actuator cylinder (SZ) and as early as the final displacement of the piston of each drive cylinder in its stroke, prior to said piston reaching its final position, at least part of the fluid stream that is provided to actuate the drive cylinder is used to actuate the actuator cylinder.