Telescopic jib for mobile crane - has sections aligned by guide during extension and secured by locking lever before bolting together

摘要

The telescopic sections for the jib of a travelling crane are aligned by a guide system after they have been extended by a hydraulic cylinder (2) so that they can be locked together. The inner section (1') has a roller carried by brackets projecting from it, travelling in a guide (3) which is shaped to align its lower surface (5') with that (5) of the outer section (5). At the same time, a locking arm (8) secured by a hinge (9) to the inner section is connected at its other end to the outer section. The guide holds the sections in tension and then the flanged ends of the two sections can be bolted together.