A crane assembly containing a boom for an overhead crane and trolley contains an arm having a first vertical portion and an outer surface, the arm fixed to the crane for upper and lower movement of the arm, and the arm containing a second portion angularly extending from the vertical portion. An outer sleeve surrounds and is fixed to the vertical portion, wherein the outer sleeve is fixed to the trolley and extends about the arm thereby defining a plenum between the outer sleeve and the inner vertical arm. During operation, the arm is adapted to be vertically moved within said outer sleeve. A support beam is fixed to the trolley, and is hingedly connected to the outer sleeve. A drive assembly is connected to the outer sleeve for rotating the boom about the support beam.

A jib assembly and a method of operating a jib assembly are provided. The jib assembly comprises: an outer section having a hollow outer body; a middle section having a hollow middle body and positioned coaxially with the outer section and located partially inside the outer section; an inner section having a hollow inner body and positioned coaxially with the middle section, and located partially inside the middle section; and a stroke cylinder having a cylinder base and a piston end, the cylinder base of the stroke cylinder being connected to a base wall of the outer section and the piston end being connected to a tip portion of the inner section, and the stroke cylinder being configured to move simultaneously the inner section from inside of the middle section and to move the middle section from inside of the outer section.

The invention relates to a mobile crane having a telescopic boom that is luffably coupled to a superstructure and that comprises a coupling section and at least one telescopic section supported therein in a retractable and extendable manner. At least one guying support is fastened to the coupling section and is connected to the coupling section or to the superstructure via a first guying and to a connection piece at a telescopic section via a second guying. In accordance with the invention, the second guying comprises at least two guying elements coupled with one another. The second guying is thereby adjustable in length and is thus adaptable to the extension length of the telescopic boom such that at least one of the mutually coupled guying elements is directly releasably connectable to the guying support. The invention further relates to a guying system for a mobile crane in accordance with the invention, to a method of moving a mobile crane in accordance with the invention into a guyed work position, and to a method of varying the extension length of the guyed telescopic boom of a mobile crane in accordance with the invention.

The invention discloses a multi-pulley telescopic mechanism, and belongs to the technical field of cranes. The multi-pulley telescopic mechanism comprises a telescopic mechanism, a first boom-extension rope, a second boom-extension rope, a third boom-extension rope, a basic boom, and a second boom, a third boom, a fourth boom and a fifth boom which are sequentially inlaid in the basic boom. The invention further discloses a crane, comprising the multi-pulley telescopic mechanism.

A cable-driven telescopic boom with several boom segments repositionable between stowed positions and deployed positions. The boom includes multiple spaced apart and separate cables that engage pulleys connected to each boom segment. A drive system can be used to apply tension to the cables to reconfigure the boom from a stowed configuration to a deployed configuration.