Folding tower crane - has vertical tie rope with sliding attachment to lower jib supporting pole

摘要

The jib folds down against the tower for transit, and there are two or more supporting poles pivoting at the tower head, from which tie ropes run to the jib and the crane superstructure. when the jib is still lying against the tower but the poles have been erected, the lowermost one is inclined rearwards in relation to the lower axis. The vertical tie rope (14) is attached to the lower pole (12) in such a manner that it can slide along it. When the jib (7) has been derricked up into the working position, the point of attachment of the tie rope to the upper pole (11) is almost directly above the point (15) where this rope is anchored to the superstructure.