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 method and a device for attaching and removing an additional device having individual elements to and from a main boom of a mobile crane using no auxiliary crane is provided. In the method, a partial piece of the additional device having partial pieces is raised into an inclined position while being rotated about an upper pivot point, and a head of the main boom is bolted to a lower end of the inclined end of the partial piece of the additional device facing the mobile crane so as to be able to rotate. Using a hoist cable, all partial pieces are raised in alignment with respect to each other and the main boom, and are bolted to each other in this position and to the main boom. A displacement device for carrying out the method is also provided.

Abstract: A boom (1) is used for receiving loads on the end thereof. The boom (1) has a metal boom hollow profile (2) extending along a boom longitudinal axis (3), and also a reinforcing layer (7) made of a fiber-plastic composite, connected to the boom hollow profile (2) at least in sections. At least one sensor element (12) is arranged in the region of the reinforcing layer (7). The sensor element (12) is used to detect strains in the boom (1).

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 vehicle crane comprises a truck carrier and a superstructure in which the driving of the superstructure function is carried out by means of hydraulic pumps in the truck carrier, and the hydraulic pumps are driven by a distributor gear unit which is arranged in the truck carrier and to which the output shaft of the vehicle drive is connected.

Abstract: A mobile crane includes an undercarriage with a middle section and two parallel crawler carriages; a superstructure on which a boom is mounted, the superstructure being connected to the undercarriage by a rotary joint; two longitudinal outriggers connected to the undercarriage and extending in the longitudinal direction between the crawler carriages; and two transverse outriggers connected to the undercarriage and extending outside the crawler carriages. One of the longitudinal outriggers has an end with a transverse beam supported by spaced apart outrigger cylinders which provide an extended tipping edge to further stabilize the crane.

Abstract: A crane having a telescoping boom whose sections, are arranged in a base boom that can telescope individually, in and out, after disengaging locking pin connections that are secured in the respective moved out or moved in positions by locking pins. A guide profile head is arranged at an end remote of the articulation of the safety locking unit to the inner end of the base boom. To lengthen the boom without substantially changing the telescopic system itself, the guide profile head is detachably fastened to the safety locking unit. An additional guide frame, whose length is dimensioned corresponding to the length of the telescoping boom that has been expanded by additional sections inserted in the telescoping boom, is mounted in place of the guide profile head, and that a guide profile head can be arranged at the free end of the guide frame.

Abstract: A crane, in particular a large crane, including a power consumer system for providing energy, a primary energy source for feeding primary energy into the power consumer system, at least one secondary energy source, independent of the primary energy source, for feeding secondary energy into the power consumer system, at least one energy storage unit arranged locally on the crane and is, in particular, associated with the at least one crane component and connected to the power consumer system for storing primary energy and/or secondary energy, at least one drive motor connected to the power consumer system for operating at least one crane component and a secondary energy source configured such that energy returned from the crane operation is at least partially fed as secondary energy into the power consumer system. The at least one crane component is configured as a secondary energy source for energy recovery.

Abstract: A large mobile crane includes a revolving superstructure, a main boom hinged to the superstructure, and a derrick boom hinged to the superstructure. A modular counterweight system includes a traveling counterweight and a non-traveling counterweight connected to a crossbeam suspended from the distal end of the derrick boom so that the non-traveling counterweight is activated before the traveling counterweight.

Abstract: A telescopic crane boom including a plurality of telescopically assembled tubular box sections including a base box section and an innermost box section having an open cross-section, and a boom head with a frame fixed to the outside circumference of the innermost box section. The head has a plurality of deflecting pulleys mounted on the frame, but no part extending inside the open cross section on the innermost base box section, whereby at least one additional box section can be inserted into the innermost box section in order to extend the boom.

Abstract: In conventional vehicle cranes it is usually necessary in consideration of current safety regulations to provide at least two separate steering circuits for all steered axles so that, in the event of a failure of one circuit, the vehicle crane can continue to be steered by way of the other. In order to avoid that in accordance with the invention at least one steered rear axle of a vehicle crane (1) is provided with a caster (a) so that at least one axle (11-16), in the event of a steering failure, remains steerable passively by utilizing the caster friction. That principle is applied in a similar manner to a module axle (2) which can be mounted to the vehicle crane (1) and which can be required for transporting additional equipment or an additional counterweight which is possibly required.

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 tracked running gear, in which two running gears are arranged parallel to one another and each running gear has a longitudinal member (1) and a running gear chain (2) which runs around the longitudinal member in the longitudinal direction thereof and forms an upper and a lower strand, and at least one traction drive, composed of a motor, transmission and a drive gearwheel which meshes into the running gear chain and also a deflecting wheel which permits chain tensioning by means of a movement relative to the fixed part of the longitudinal member, characterized in that at least one additional traction drive (3) which acts on the upper strand is provided on the longitudinal member, wherein the running gear length is changed or remains unchanged.

Abstract: A boom (1) is used for receiving loads on the end thereof. The boom (1) has a metal boom hollow profile (2) extending along a boom longitudinal axis (3), and also a reinforcing layer (7) made of a fiber-plastic composite, connected to the boom hollow profile (2) at least in sections. At least one sensor element (12) is arranged in the region of the reinforcing layer (7). The sensor element (12) is used to detect strains in the boom (1).

Abstract: A rear axle steering system for a mobile crane includes at least one actively steered rear axle with wheels arranged thereon. A rear axle steering system of this type is provided with a hydraulic steering system including one or more hydraulic steering cylinders of which a particular number are in each case associated with an actively steered rear axle in order to steer this actively steered rear axle in a desired manner. A braking system is adapted to individually brake each wheel of the at least one actively steered rear axle. In the event of an error in the hydraulic steering system, a control system actuates the braking system in such a way that by selective braking of at least one wheel of the actively steered rear axle, which is affected by this error, the rear axle is brought to a predetermined, desired steering position. A method of steering a rear axle, with wheels of a mobile crane arranged thereon, by means of a hydraulic steering system.

Abstract: The invention relates to a crawler crane comprising two crawler supports (9) with rotating crawlers (8). Both crawler supports (9) are connected by a transversal bridge (10). A superstructure (3) of the crawler crane comprises at least one crane jib that can pivot about a vertical axis and is connected to the transversal bridge (10). A pivotable articulation connects the transversal bridge (19) in a pivotable manner to the crane superstructure (3). At least one of the crawler supports (9) is connected to the transversal bridge (10) by means of a double link (11). A lower link (12) of the double link (11) is articulated on the crawler support (9) by means of a crawler support lower pivotable axis (13) and on the transversal bridge (10) by means of a transversal bridge lower pivotable axis (14).

Abstract: An element is provided for connecting the chords of a lattice system, which consists of upper chords and lower chords, between which struts and/or stays are arranged, to a telescopic boom head. Thereby, the lower chords are directly connected to the telescopic boom head by means of bolts, while the upper chords can be connected to the telescopic boom head by a connecting element of variable length in such a way that—with respect to the connection of the lower chords—the upper chords can be connected to one another at a variable angle, and wherein the connecting element consists of two butt straps which can each be fastened at one end of mutually facing ends of the upper chords and can be connected to one another at different points.

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 mobile crane includes an undercarriage with a middle section and two parallel crawler carriages; a superstructure on which a boom is mounted, the superstructure being connected to the undercarriage by a rotary joint; two longitudinal outriggers connected to the undercarriage and extending in the longitudinal direction between the crawler carriages; and two transverse outriggers connected to the undercarriage and extending outside the crawler carriages. One of the longitudinal outriggers has an end with a transverse beam supported by spaced apart outrigger cylinders which provide an extended tipping edge to further stabilize the crane.