A crane, in particular a mobile crane, includes a crane jib which can be moved about a substantially horizontal luffing axis, and a tensioning device for the crane jib. The tensioning device includes two pendants which run from the jib tip to the jib base of the crane jib and tensioning posts each tensioning a respective one of the pendants relative to the crane jib in a triangular configuration. In order to operate the crane, a luffing angle of the crane jib about the luffing axis is measured or recorded, and a spread angle between the tensioning posts while the crane jib is being used is modified depending on the luffing angle.

The present disclosure includes a telescopic bearing assembly capable of withstanding predetermined bending loads and at the same time is fully telescopically extendable, while minimizing a wall thickness (t) in each of tubular bearing sections of an associated telescopic arm. Additionally, the present disclosure includes a mobile hydraulic telescopic crane with a telescopic arm with such an assembly.

A vehicle crane, such as a mobile crane or a crawler crane, includes a main boom, a main boom extension, and an adapter that is located between the main boom and the main boom extension and which has a first connection plane and a second connection plane. The adapter is configured to be movable such that the first connection plane can be moved relative to the second connection plane, where the adapter is designed in the manner of a double lever in order to provide a vehicle crane that has improved load-bearing capacity and simplified set-up.

The present disclosure refers to a mobile telescopic hydraulic crane, which may include at least one service opening in a terminal portion of a telescopic section adjacent to at least one hydraulic connector, wherein said at least one service opening is configured to allow access for a hand tool from the outside of the telescopic section to establish or disassemble a hydraulically sealed connection between a flexible hydraulic pipe and associated hydraulic connector within said telescopic arm. The at least one service opening allows for a quick and simple replacement of each hydraulic pipe within the telescopic secondary arm without significantly reducing the carrying capacity and reach of the crane.

A lightweight and high-rigidity telescopic boom in which strain during manufacturing is suppressed is disclosed. In a telescopic boom, a plurality of booms forms a telescope structure, and the telescopic boom includes a boom fixing mechanism that fixes a top boom disposed relatively inside at a predetermined position with respect to a first intermediate boom disposed relatively outside. The boom fixing mechanism includes a boom fixing pin that is provided to the top boom and advances and retreats with respect to the first intermediate boom, a fixing boss that is provided to the first intermediate boom and into which the boom fixing pin is inserted and extracted, and a gap maintaining member that is provided to the fixing boss and protrudes outward to maintain a gap between the first intermediate boom and a second intermediate boom disposed further outside.

Telescopic lattice type crane boom for a crane, further comprising a locking system configured to lock at least one telescopic boom section with respect to a base boom section in at least an extended position, wherein said locking system includes a plurality of pins, each pin being configured to extend, in at least the extended position of the boom, at least partly through a corresponding pin receiving aperture provided in one of the base boom section and the at least one telescopic boom section.

This crane is configured by being provided with: a telescopic boom having an inside boom element and an outside boom element that overlap each other in an extendable and contractible manner; an extension/contraction actuator that displaces one boom element among the inside boom element and the outside boom element in the extending and contracting directions; at least one electric drive source provided in the extension/contraction actuator; a first coupling mechanism that operates on the basis of power from the electric drive source and that switches between the coupled state and the uncoupled state of the extension/contraction actuator and one of the boom elements; and a second coupling mechanism that operates on the basis of power from the electric drive source and that switches between the coupled state and the uncoupled state of the inside boom element and the outside boom element.

The present apparatus relates to an apparatus for the guying of a lattice boom of a crane, in particular of a mobile crane, comprising a frame and two connection elements connected thereto, wherein the frame has first attachment means for a releasable connection of the apparatus to a guying of the crane and wherein the connection elements have two attachment means for a releasable fastening of the apparatus to the boom. In accordance with the invention, the apparatus can be assembled at the boom for assembly thereat and can be removed again after the boom has been assembled. The present invention further relates to a respective method for the in the air assembly and for the restoring to the original state and the guying of a lattice boom by means of the apparatus in accordance with the invention.

The present apparatus relates to an apparatus for the guying of a lattice boom of a crane, in particular of a mobile crane, comprising a frame and two connection elements connected thereto, wherein the frame has first attachment means for a releasable connection of the apparatus to a guying of the crane and wherein the connection elements have two attachment means for a releasable fastening of the apparatus to the boom. In accordance with the invention, the apparatus can be assembled at the boom for assembly thereat and can be removed again after the boom has been assembled. The present invention further relates to a respective method for the in the air assembly and for the restoring to the original state and the guying of a lattice boom by means of the apparatus in accordance with the invention.

A hydraulic crane comprising: —a rotatable column (7); —a crane boom system (10) comprising two or more liftable and lowerable crane booms (11, 13); and —an electronic control device (25), which is configured to prevent an execution of crane boom movements that would make the lifting moment of the crane exceed the maximum allowed lifting moment of the crane, and to continuously establish position information as to the prevailing position of the load suspension point (P) of the crane boom system. When the lifting moment of the crane has reached a limit value at a given level below the maximum allowed lifting moment, the electronic control device is configured to prevent the execution of any combination of crane boom movements that would increase the horizontal distance between the load suspension point and said vertical axis of rotation and at the same time allow the execution of any combination of crane boom movements that keeps said horizontal distance unchanged or reduces said horizontal distance.