Tower crane with foldable counter-jib

摘要

The crane has a jib (10) with no strain cable which is mounted at the top of a mast (4) and extended rearward from its connection point (9) to the mast top by a backward cantilever extension (14) whose end (29) is connected by a rear strain cable (19) to a crane chassis (2). For transport of the crane, the backward extension is folded into a vertical plane on the jib rear part (11). The unfolding and folding of the extension are carried out automatically and simultaneously with the automatic erection or dismantling of the crane.