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: Method for adjusting the angle of a jib system of a crane, comprising the steps of providing two jib units of the jib system, which can be variably arranged with respect to their longitudinal axes in an angle position in relation to one another, arranging connecting links attached to the jib units in such a way that the longitudinal axes of the jib units are parallel in a starting angle position, starting openings and target openings of the connecting links are aligned with one another pairwise to insert a connecting element connecting the jib units, the aligned starting openings being connected with the connecting element, relieving the connecting element connecting the aligned starting openings, removing the first connecting element, connecting a pair of the aligned target openings with the connecting element, and arranging the jib units in a target angle position which is different from the starting angle position.

Abstract: The invention concerns a lattice boom crane, which is composed of at least two individual lattice boom cranes (1, 11), which each comprise a luffing lattice boom (4, 14), whose luffing angle is adjustable by a luffing mechanism (5, 15). The lattice booms (4, 14) of the individual lattice boom cranes (1, 11) are connected with each other and oriented in parallel and adjacent to each other and the luffing mechanisms (5, 15) of the lattice boom cranes (1, 11) are synchronously operated, such that the rigidly-connected lattice booms (4, 14) are synchronously luffable.

Abstract: An auxiliary device for equipping the main boom of a mobile crane with an auxiliary boom, wherein a support is mounted near the head of the main boom, by means of which the lifting cable of the main boom may be run to a connection point on the auxiliary boom. The invention further relates to a method for equipping with an auxiliary boom.

Abstract: A locking and bolting unit for sections telescoping out of a basic element, in particular sections of a telescoping boom of a mobile crane. The invention involves a locking and bolting unit for sections telescoping out of a basic element, in particular sections of a telescoping boom of a mobile crane, comprising two safety bolts (3) arranged displaceably relative to each other, and an interlocking bolt (5) interacting with a grasper (4). Moreover, the safety bolts (3) and an extension of the grasper (4) constructed as a piston rod (5) are positioned together in a lower housing section vertically displaceable in relation to each other and the piston (6) for the piston rod (5) of the grasper (4) is located in an upper housing part (2) placed on a lower housing part (1).

Abstract: The invention relates to a method and to a device for attaching and removing an additional device comprising individual elements to and from the main jib of a mobile crane using no auxiliary crane. In the method according to the invention, a partial piece (2.1) of the additional device (2) composed of partial pieces is raised into an inclined position while being rotated about an upper pivot point (C), and the head (1.2) of the main jib (1.1) is bolted to the lower end of the inclined end of the partial piece (2.1) of the additional device (2) facing the mobile crane so as to be able to rotate. Using a hoist cable (7), all partial pieces (2.1 to 2.7) are raised in alignment with respect to each other and the main jib (1.1), and are bolted to each other in this position and to the main jib. The invention furthermore relates to a displacement device for carrying out the method according to the invention.

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 utilising 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 present invention relates to a rope winding system (1) for winding and unwinding a steel rope (4) of a crane (7). A rope winding system (1) according to the present invention has a rope drum (6), onto which the steel rope (4) can be wound in a plurality of layers, and a magnetic system (7) which is configured to generate a magnetic field over a section of the steel rope (4) with its magnetic flux being deflected by a movement of the steel rope (4) in such a way that the steel rope (4) is braked. A crane (7) is also discloses which is equipped with such a rope winding system (1) for winding and unwinding a steel rope (4).

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.

Abstract: A device for installing the lower and upper jib support of an adjustable auxiliary boom. The device includes a setup frame which is connected to the lower jib support a tie rod section one end of which can be connected to the hoist cable of the main hoisting gear whereas the other end is hinged to the top of the lower jib support and a tensile member section between the lower jib support and the upper jib support.

Abstract: The invention relates to a combination double bottom hook block in which two pulley blocks (2, 3) each with a plurality of pulleys are connected to one another by means of a rocker (1), a load hook being mounted in a pivotable manner on the rocker. If use is made here of two lifting cables, each of these lifting cables is led over a pulley block (2, 3) and, in order to achieve the same loading capability if use is made of just one lifting cable, the latter is led, in addition, over a floating pulley (2) which is mounted between the two pulley blocks (2, 3), the two pulley blocks (2, 3) also being secured against tilting.

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 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: The object of the invention is to reduce the amount of investment required for the usage-optimized configuration and installation of large cranes. This object is achieved by a large mobile crane having an undercarriage, a drive unit (16), a revolving superstructure (18), one or more control stations (17), at least two jibs (3), at least one counter-jib (4), at least two lifting arrangements (22) and counterwvejghts arranged separately or on the basic structure, characterized in that the load-bearing parts of the crane (3, 4, 20) and the mobility-specific parts (5, 6, 7) are of modular design and can be supplemented by exchangeable and/or supplementary parts, wherein the structural units (modules) used essentially correspond, or are similar, to existing standard-crane components, and an increase in load-bearing capacity can be achieved by arranging a number of these in the large crane.

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: The invention relates to a combination double bottom hook block in which two pulley blocks (2, 3) each with a plurality of pulleys are connected to one another by means of a rocker (1), a load hook being mounted in a pivotable manner on the rocker. If use is made here of two lifting cables, each of these lifting cables is led over a pulley block (2, 3) and, in order to achieve the same loading capability if use is made of just one lifting cable, the latter is led, in addition, over a floating pulley (2) which is mounted between the two pulley blocks (2, 3), the two pulley blocks (2, 3) also being secured against tilting.

Abstract: The invention refers to a truck roller assembly (12) for a crawler chain comprising at least two spaced track roller portions (5, 5?) with running surfaces for running on the crawler chain (13), and a star-shaped element (6) for guiding the track roller assembly (12) on the crawler chain (13). The star-shaped element (6) is mounted freely rotatably between the at least two track roller portions (5, 5?), and it is provided with a plurality of teeth (6?, 6?, 6??, 6??, 6???). The teeth (6?, 6?, 6??, 6??, 6???) co-operate with the crawler chain (13) in such a way that on rolling over chain links (3) of the crawler chain (13) they engage into corresponding gaps (8) in the crawler chain (13).

Abstract: A rear axle steering system for a mobile crane including 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: 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: 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.