Crane has telescopic jib with jib sections with retractable and extendable running tracks for travelling crab which from first jib section continue onto second jib section with same track width

摘要

The crane has a telescopic jib with a travelling crab (4). The jib sections (2,3) have retractable and extendable running tracks for the crab which from the first jib section continue onto the second jib section with the same track width. The jib sections have longitudinal booms sliding one inside the other and form the running tracks for the crab. The longitudinal booms (7,8) of the first jib section have a slotted longitudinal opening and is especially C-shaped or U-shaped for a static diagonal connection, and grip round the longitudinal booms (11,12) of the second jib section.