An expansion/contraction mechanism includes a telescopic cylinder, boom fixing means, cylinder-boom connecting means, and a hydraulic-pressure supply unit, and telescopes a plurality of booms except a base boom by telescoping the telescopic cylinder. The hydraulic-pressure supply unit includes a pneumatic-pressure source, a selector valve which selects a destination of air provided from the pneumatic-pressure source, a first pneumatic path through which first air sent from the selector valve circulates, a second pneumatic path through which second air sent from the selector valve circulates, a first pneumatic-to-hydraulic conversion unit which converts a pneumatic pressure provided by the first air to a hydraulic pressure and supplies the hydraulic pressure to a first hydraulic cylinder, and a second pneumatic-to-hydraulic conversion unit which converts a pneumatic pressure provided by the second air to a hydraulic pressure and supplies the hydraulic pressure to a second hydraulic cylinder.

A crane controller for a crane, in particular a cargo crane, has a first operating mode, in which the crane can be user-operated by control commands from an operator, and a second operating mode that can be activated by the operator. In the second operating mode, the crane geometry can be changed by the crane controller in a pre-defined sequence of movements. The crane controller has a menu-drive user interface, and the interface has a function which can be selected by the operator and by which the crane controller switches from the first to the second operating mode.

A crane system includes a skid assembly having an operator base and plurality of outrigger assemblies coupled to the operator base that support and lift the base from a first elevation to a second elevation. The crane system also includes a jib crane coupled to the skid assembly. The jib crane includes a pillar assembly coupled to the skid assembly and a boom assembly coupled to the pillar assembly.

Crane assemblies for attachment to a vehicle tow hitch are described.

The crane includes a swing brake device installed between a hydraulic motor and a control valve and having a flow restrictor; a first backpressure detector detecting a motor backpressure between the flow restrictor and one of ports of the hydraulic motor; a second backpressure detector detecting a motor backpressure between the flow restrictor and the other port of the hydraulic motor; and a control device. The control device has an external-force direction estimation unit that estimates a swing direction of an upperstructure under an external force acting on the upperstructure on the basis of a motor backpressure detected by the first backpuressure detector and a motor backpressure detected by the second backpressure during an operating state of the swing brake device. The control device has a notification control unit that causes the notification device to provide notification of the estimated swing direction of the upperstructure.

A removable hoist assembly for lifting a load up and into a confined space in the form of a kit has a support structure releasably coupled to overhead structural beams in the confined space, a motor releasably coupled to the support structure above the support structure between the overhead structural beams, a hoist arm releasably coupled to the support structure to be rotatable and extendable with respect to the support structure, and a cable supported by the hoist arm. The cable has a free end positioned proximate a distal end of the hoist arm and configured to couple to the load and a terminal end coupled to the motor such that the cable extends and retracts with respect to the motor. The hoist arm support structure spreads the weight of the motor, hoist arm and the load across a plurality of the overhead structural beams.

A securement for crawler cranes and system and method for use of the same are disclosed. In one embodiment of the system, a pair of structural securements are spaced at approximately a track-distance apart with respect to the crawler crane and coupled together by multiple transverse support members. When the crawler crane is driven onto the structural securements and fastened thereto, the tipping fulcrum of the crawler crane is shifted, thereby requiring a greater tipping force to tip and adding stability during high wind events.

A securement for crawler cranes and system and method for use of the same are disclosed. In one embodiment of the system, a pair of structural securements are spaced at approximately a track-distance apart with respect to the crawler crane and coupled together by multiple transverse support members. When the crawler crane is driven onto the structural securements and fastened thereto, the tipping fulcrum of the crawler crane is shifted, thereby requiring a greater tipping force to tip and adding stability during high wind events.

The present invention relates to a ballast apparatus for attaching to the rear of a crane superstructure, in particular of a crawler-mounted crane, having a base plate and a plurality of stackable ballast plates, wherein at least two carrier plates for receiving stacked ballast plates are connected to the base plate in an articulated manner pivotable about vertical pivot axes.

The invention relates to a drive device for supplying power to multiple engine pumps (4, 5), provided in the superstructure (3) of a mobile crane for superstructure functions, by way of a drive motor (2) arranged in the undercarriage (1) of the mobile crane, comprising a hydraulic motor (7) which is arranged in the superstructure (3) and hydraulically driven by the drive motor (2) and which comprises a first mechanical output which couples at least one first engine pump (4) to the hydraulic motor (7) and a second mechanical output which couples at least one second engine pump (5) to the hydraulic motor (7). The invention also relates to a mobile crane comprising this drive device.