ausfahrbarer tower or mast. hoisting device

摘要

A self-erecting tower structure, for example, for overhead inspection and for supporting lights, aerials, antennas, and cameras. The structure includes an extensible member comprising a number of superimposed frames and self-erecting legs interconnecting the frames and erecting means, such as endless chains or a screw-threaded column, arranged to raise each of the frames in succession through a distance at least equal to the length of the legs.