This overload preventing device is mounted on a mobile work machine, and is provided with: a storage unit which stores lifting performance data; and a work machine control unit which controls operation of the mobile work machine on the basis of the actual load and the lifting performance corresponding to the present operation state of the mobile work machine. A third lifting performance configured for a transition region, a first switching angle defining the boundary between the front region and the side region and the boundary between the back region and the side region when the outriggers are in different states of deployment, and a second switching region defining a transition region in the side region are configured on the basis of stability calculations and strength factors such as jack strength.

A mobile lifting apparatus, comprising at least one truck, provided with a first drive device comprising at least one internal combustion engine connected by power transmission means to one or more user devices of the truck hydraulically actuated, and at least one boom provided with a second drive device.

A crane includes a base, an upperstructure rotationally mounted on the base, a boom, and a gantry. The boom is pivotally attached to the upperstructure at a front attachment location and supports a load line operable to raise a payload. The gantry is mounted on the upperstructure and supports a boom line coupled to the boom. The gantry includes at least one front leg mechanically coupled to the front attachment location and inclined away from the boom to apply, to the front attachment location, a horizontal force component towards the boom opposed by a horizontal force component applied by the boom towards the front leg. The upperstructure includes a frustoconical turret forming an upper circle and a lower circle. The front attachment location is aligned over the upper circle of the frustoconical turret.

A crane 1, the hook (main hook 24) of which is stored on the lower end of a boom 7, and the winch (main winch 9) of which can be moved by a hydraulic motor 37, said crane being provided with a pressure sensor 55 capable of detecting the pressure of hydraulic fluid being delivered to the hydraulic motor 37, and a controller 61 capable of recognizing changes in the pressure of the hydraulic fluid on the basis of a signal from the pressure sensor 55, and also being provided with an anomaly warning means Mi capable of providing warning of anomalies pertaining to the storage of at least the hook (24), the controller 61 activating the anomaly warning means Mi when it is determined that the pressure of the hydraulic fluid when the hook has been stored is below a minimum value.

A machine includes a frame, ground-engaging elements coupled to the frame, and a hoisting system having a sideboom and a fairlead. The hoisting system also includes a hook pulley block and a hoisting cable extending through the fairlead and the hook pulley block and held in tension such that the hoisting cable couples pivoting of the fairlead to pivoting of the sideboom. The pivotable fairlead may be instrumented with position, cable loading, and cable feed sensors.

A crane, a method for assembly of a crane and a method for disassembly of a crane are disclosed. In accordance with the method, a first mast is fixed in a vertical position. A top mast section of a second mast is positioned adjacent to and outside of the first mast. The top mast section is moved vertically upwards, and this movement is guided by a guide system. Then, the top mast section is fixed relative to the first mast at a position which is at a larger vertical distance from the crane base. Then, a first intermediate mast section of the second mast is fixed to a lower end of the top mast section to build up the second mast. Then, the first intermediate mast section is connected to a pivot, and the second mast is pivoted away from the first mast.

A hoisting system for a machine includes a winch assembly, and a boom such as a sideboom that is pivotable. The hoisting system further includes a fairlead supported at a fixed orientation such that a feed angle of a hoisting cable extending through the fairlead varies in response to pivoting of the boom. A hoisting control system for the machine includes a cable state sensing mechanism resident on the fairlead and structured to produce cable monitoring data indicative of at least one of a cable feed length, a cable feed angle, or a cable load, and an electronic control unit structured to output an alert based on the cable monitoring data.

A structure installation system which maintains one or more walls in a desired position and orientation during installation of the one or more walls. The structure installation system generally includes a vehicle which is adapted to traverse a ground surface. The vehicle includes an arm having an arm coupler to which a support is connected. One or more walls adapted to be installed in the ground surface may be removably connected to the support, such as by securing the walls to adjustable hangers that are removably connected to the support. By adjusting the positioning of the hangers, the orientation and position of the walls may be adjusted. Once put in position, the vehicle and support will retain the walls in the desired position and orientation while concrete is poured and allowed to cure to form a unitary structure such as a bollard wall.

A vehicle-mounted reel lifting apparatus for rotating the reel to dispense or wind the reelable material. A driven wheel engages the rim of the reel at a plurality of reel lifting arm pivot positions, such as sliding alongside the lifting arm in an axis parallel with the lifting arm. The driven wheel is capable of engaging with the reel at any position of the lifting arm. A linear drive mechanism allows the driven wheel to travel up and down the lifting arm to accommodate various reel sizes. The lifting arm may incorporate an automatic locking slot having a spring-driven locking mechanism. The lifting arms may also be mounted with a mounting bracket having a pattern of slots to enable the lifting arms to be selectively mounted in a narrow configuration or a wide configuration.

Provided is a crane that is capable of effectively suppressing oscillation related to the pendulum resonance frequency generated in a suspended load on the basis of the suspended length of a wire rope. The crane 1 calculates a suspended load oscillation resonance frequency x(n) determined on the basis of the suspended length L(n) of a wire rope (14.Math.16), and generates a control signal C(n) for an actuator according to an arbitrarily defined operation signal, and, on the basis of the resonance frequency x(n), generates from the control signal C(n) a filtering control signal Cd(n) for the actuator in which a frequency component in an arbitrarily defined frequency range is attenuated by an arbitrarily defined percentage. The frequency range of the attenuated frequency component and/or the percentage of attenuation is altered on the basis of the suspended length L(n) of the wire rope (14.Math.16).