Crane with telescopic boom - has individual sections movable by hydraulic piston cylinder unit whose displaceable element has at inner and outer ends security locking units to couple with recesses in telescopic sections

摘要

The crane is operated by a hydraulic piston cylinder unit. A security locking unit is provided at the inner and outer ends of the displacement element (6) of the piston cylinder unit and couples with recesses on the telescopically extending sections (2-5). The piston rod of the unit is attached by its rear end to the inner end of the foundation boom (1) and the two security locking units are mounted at the inner and outer end of the displaceable cylinder housing. The security locking units consist of a hydraulic block with opposing cylinders for the movable bolts which lock the relevant section and of a hydraulic piston cylinder unit mounted at a right angle for operating the relevant locking bolt.