Abstract: A walking excavator (1) having a superstructure (2) and an undercarriage (29), and a cab (3) disposed on the superstructure (2), and four walking legs (4) pivotably disposed on the undercarriage (29), and an excavator arm (5) which is pivotably mounted on the superstructure (2) and to which an excavating tool (6), in particular an excavator bucket, is fastened or able to be fastened. A dual-action differential cylinder (7) pivots the excavator arm (5) up and down relative to the superstructure (2) and is articulated on the superstructure (2), on one side, and on the excavator arm (5), on an other side. For applying additional force along with the dual-action differential cylinder (7) when pivoting the excavator arm (5) down relative to the superstructure (2), a single-action differential cylinder (8) is additionally articulated on the superstructure (2), on one side, and on the excavator arm (5), on an other side.

Abstract: A pump arrangement for pumping a liquid, in particular a liquid contaminated with dirt particles, the pump arrangement having at least one working chamber (1, 2, 11, 12) and at least one delivery piston (3, 4, 13), and at least one inlet valve (7) and at least one outlet valve (8), and the delivery piston (3, 4, 13) being movable in order to suck liquid into the working chamber (1, 2, 11, 12) through the inlet valve (7) and to eject liquid out of the working chamber (1, 2, 11, 12) through the outlet valve (8), and the pump arrangement having a wear-monitoring device (40) for monitoring the wear on the inlet valve (7) and/or outlet valve (8) with at least one pressure sensor (41) and one pressure evaluation unit (42) for processing pressure measurement values output from the pressure sensor (41), wherein the pump arrangement, for the purpose of moving the delivery piston (3, 4, 13), has a drive fluid system (20) that can be operated with a drive fluid, and the pressure sensor (41) of the wear-monitoring device

Abstract: An excavator-hoist including a chassis for supporting an operator's cab, a drive assembly, and a boom with a working tool supported at the free end of the boom, two pairs of projecting pivotable arms connected to opposite end sides of the chassis, respectively, for supporting at their free ends two pairs of wheels, with the arms, which support the front wheels having free end portions offset relative to respective remaining portions of the front wheel supporting arms in a vertical plane, with the front wheels being carried by the offset portions of the arms, and with respective piston-cylinder units, which are provided for pivoting the front wheel supporting arms in respective vertical planes, having one of their respective ends attached to the respective arms above pivot axes of the respective arms, and having another of their respective ends attached in respective regions of bottoms of the respective arms.