A working machine includes a lower body, a turning body, a turning manipulating member which turns the turning body, a hydraulic motor which rotationally drives the turning body, a brake device which brakes the hydraulic motor, a main hydraulic source which supplies hydraulic oil to the hydraulic motor, and a direction control valve which controls a flow direction of the hydraulic oil according to the manipulated variable of the turning manipulating member, in which in a state where the hydraulic motor is braked by the brake device based on a manipulation of a brake manipulating member, when the turning manipulation is performed by the turning manipulating member, a brake applied to the hydraulic motor by the brake device is released with respect to turning in an indication direction indicated by the turning manipulation such that the turning body turns in the indication direction.

A boom truck includes a truck chassis having a frame, a boom assembly connected to the frame, and a boom counter weight assembly rotatably connected to the boom assembly. The boom counter weight assembly is configured to be disposed between a first position to extend a wheel base of the boom truck and a second position to define a counterweight relative to the boom assembly.

A mobile crane having a main jib that is mounted thereupon for luffing and that can be oriented by means of a luffing cylinder, and a main jib extension which is detachably connected to a main jib head of the main jib by upper and lower bolts, it being possible to angle the main jib extension about a luffing axis relative to the main jib proceeding from a base position following release of the upper or lower bolts and using an angle drive, the angle drive engaging with a foot of the main jib extension, a maximum angling angle being delimited by an adjustable angling plate, and the angling plate engaging with the foot of the main jib extension and the main jib head. The angle drive is a component of an angling plate in the form of a combi-angling plate.

A mobile crane having a main jib that is mounted thereupon for luffing and that can be oriented by means of a luffing cylinder, and a main jib extension that is detachably connected to a main jib head of the main jib by means of upper and lower bolts, it being possible to angle the main jib extension about a luffing axis relative to the main jib proceeding from a base position following release of the upper or lower bolts and using an angle drive, the angle drive engaging with a foot of the main jib extension, a maximum angling angle being delimited by an adjustable angling plate, and the angling plate engaging with the foot of the main jib extension and the main jib head. The angle drive may be a component of an angling plate in the form of a combi-angling plate.

A crane housing having a substantially cylinder-shaped circumferential wall with a lower section and lower end mounted to a slew bearing of substantially the same diameter includes a boom support structure to support an inner end of a pivotal boom arranged at a front side of the crane housing. The boom support structure includes at least two box elements of each of which an end portion overlaps with and is integrated with the upper section of the circumferential wall. Oblique strengthening ribs are mounted onto and integrated with a side of the circumferential wall and extend from a respective box element end portion in an oblique downwards direction towards the lower end of the wall.

A construction machine improves ease of assembly of travelling body weights installed in a truck frame and allows a worker to easily move between one pair of side frames through the travelling body weights. The construction machine includes a lower travelling body of a crane includes a truck frame, a left side frame and a right side frame, and a front weight and a rear weight. The front weight and the rear weight each include a lower weight and an upper weight. An upper surface part of the upper weight extends continuously along a left and right direction, and a moving passage is formed between the one pair of side frames.

A method for securing an angular position of a crane jib displaceable in lifting and in lowering by a winch integrating a motor driving a drum on which is wound a rope and secured to a platen provided with arcuate oblong locking holes, the method including measuring a speed parameter representative of an angular speed of the jib, controlling the motor to displace the jib with a limitation of the speed parameter to a first maximum value and a limitation of a motor torque to a first limit value, until reaching an angular position in which a lock is aligned with and locked into the locking hole, and controlling the motor to displace the jib in lowering with a limitation of the speed parameter to a second maximum value and a limitation of the motor torque to a second limit value, until the speed parameter is null for a predetermined time period to stop the motor.

The present disclosure relates to a lifting device, in particular a mobile crane or a cable-operated excavator, that comprises a superstructure, a main boom that starts from the superstructure, a luffing boom that starts from the end of the main boom remote from the superstructure, a winch arrangement, and a tilting moment detection unit for determining the tilting moment acting on the lifting device by the position of the main boom and the luffing boom. The disclosure is characterized by an apparatus for assisting or for fully automatic carrying out an erecting and/or placing down procedure of a boom system comprising the main boom and the luffing boom that is configured to carry out the steps for erecting and/or placing down the boom system in dependence on the tilting moment detected by the tilting moment detection unit.

A vehicle crane having a superstructure with a jib system including a main jib mounted in a luffable manner on the superstructure, with a jib head and a luffable additional jib and at least one luffing support supported in the region of a luffing axis of the additional jib. At least one guying support of the jib system is arranged in such a manner that a tensioner starting on the one hand from the superstructure and/or from a counterweight and connected on the other hand to the additional jib is guided via the at least one guying support and the at least one luffing support. A main jib extension is incorporated between the jib head and the additional jib with the at least one guying support supported at the main jib extension to obtain a longer design of the jib system with the highest possible permissible bearing load.

The present disclosure relates to a mobile crane, which comprises a superstructure, a main boom, which extends away from the superstructure and is arranged so as to be pivotable thereon, a derrick boom, which extends away from the superstructure and is arranged so as to be pivotable thereon, and a winch assembly, wherein the winch assembly comprises a main-boom winch for actuating the main boom and a derrick-boom winch for actuating the derrick boom. The mobile crane is characterised by an assistance apparatus for facilitating or fully automatically carrying out a raising and/or setting-down process of the derrick boom, which apparatus is designed to actuate the main boom and the derrick boom, such as the main-boom winch and the derrick-boom winch, at the same time.