Abstract: A drive of a sliding connecting member of a locking system of a telescopic system, having a telescopic cylinder (1) with an outer telescopic section (2, 3) and an inner telescopic section (6, 7), which are each provided with a locking hole (5) into which a locking bolt (11) can be entered and withdrawn in a releasable manner via the sliding connecting member (14), provided with a sliding path (12), and a grasper (10), wherein the locking bolt (11) is designed to be moveable by means of an engagement member (9) running in the sliding path (12) in such a way that the locking bolt (11) effects a linear movement and the jib sections (3, 6) can be connected to one another by insertion of the locking bolt (11) into the bolting hole (5) and the sliding connecting member (14) can be driven by an electric linear drive (4).

Abstract: A drive of a sliding connecting member of a locking system of a telescopic system, having a telescopic cylinder (1) with an outer telescopic section (2, 3) and an inner telescopic section (6, 7), which are each provided with a locking hole (5) into which a locking bolt (11) can be entered and withdrawn in a releasable manner via the sliding connecting member (14), provided with a sliding path (12), and a grasper (10), wherein the locking bolt (11) is designed to be moveable by means of an engagement member (9) running in the sliding path (12) in such a way that the locking bolt (11) effects a linear movement and the jib sections (3, 6) can be connected to one another by insertion of the locking bolt (11) into the bolting hole (5) and the sliding connecting member (14) can be driven by an electric linear drive (4).

Abstract: The invention relates to a monitoring and alarm device for construction machinery having long and heavy booms, such as cranes, in particular mobile cranes, is characterized in that a monitor system is provided, which monitors parameters that may change in case of an undesired lowering of the boom or of boom sections in a non-operating condition, and triggers an optical and/acoustic and/or wireless alarm system if the parameters change.

Abstract: A hydraulic control circuit for the overcontrol of a hydraulic system which controls a drive, in particular for controlling a hydraulic motor (5) for driving a slewing gear of a crane superstructure, wherein the pressure lines (3.9, 3.10) for the hydraulic motor (5) are connected by means of a supply piston (3.2) to a hydraulic pump (2) or a tank (1), and the pressure lines (3.9, 3.10) are each assigned pilot valves (3.4, 3.3), shuttle valves (3.8, 3.7) and directional control valves (3.6, 3.5). The shuttle valves (3.7, 3.8) are connected by means of control lines (3.11, 3.12) to an activatable proportional pilot valve (6), such that the separately activatable directional control valves (3.5, 3.6) can thus be activated by means of said pressure, which is built up by the pilot valve (6).

Abstract: The invention relates to a monitoring and alarm device for construction machinery having long and heavy booms, such as cranes, in particular mobile cranes, is characterized in that a monitor system is provided, which monitors parameters that may change in case of an undesired lowering of the boom or of boom sections in a non-operating condition, and triggers an optical and/acoustic and/or wireless alarm system if the parameters change.

Abstract: The invention relates to a hydrostatic drive system having a pump (1) and at least one consumer (6) that can be connected alternately to the pump (1) and to a tank (3) by means of a directional control valve (4) that can be actuated by control signals (15, 16), in order to control the motion of a positive or a negative load (9) at the consumer. Provision is made to this effect that there is disposed in the line (13) of the negative connection of the consumer that leads via the directional control valve (4) to the tank (3) a pre-charge valve (5, 51, 60) that can be placed under a pressure that can be controlled via a programmable logic unit (31) when controlling a positive load.

Abstract: A hydraulic control circuit for the overcontrol of a hydraulic system which controls a drive, in particular for controlling a hydraulic motor (5) for driving a slewing gear of a crane superstructure, wherein the pressure lines (3.9, 3.10) for the hydraulic motor (5) are connected by means of a supply piston (3.2) to a hydraulic pump (2) or a tank (1), and the pressure lines (3.9, 3.10) are each assigned pilot valves (3.4, 3.3), shuttle valves (3.8, 3.7) and directional control valves (3.6, 3.5). The shuttle valves (3.7, 3.8) are connected by means of control lines (3.11, 3.12) to an activatable proportional pilot valve (6), such that the separately activatable directional control valves (3.5, 3.6) can thus be activated by means of said pressure, which is built up by the pilot valve (6).

Abstract: The invention relates to a controller for an adjustable jib extension of a mobile crane, comprising a telescoping main jib and a jib extension placed thereon, the luffing angle of the extension being adjustable by way of a luffing winch or a piston-cylinder unit. For this purpose, the actuation of the winch moving the luffer or of the piston-cylinder unit is carried out via a control circuit such that during the extension and/or retraction of the telescoping jib, or when changing the angle of the main jib with respect to the horizontal, the angle of the luffer with respect to the telescoping main jib and/or the horizontal remains constant or changes to a predefined extent.