Telescopic mast or tower for deep drilling or radio antennae - with safe, rigid structure which can be contracted to low overall height

摘要

The mast has a base(a) carrying a lower metal frame(b), and contg. an intermediate mast section(c) formed by lattice girders. A top mast section(d) can be fixed to section(c) by bolts; and a winch is used to lift section(c) in section(b). Section(b) contains hinged brackets for anchoring section(c) in a raised position. Section(b) is provided with two rows of rollers and, when this section(b) is lowered in section(a), the rollers rest on two tracks so section(b) can be moved sideways in section(a). Each section(b,c,d) contains a pair of vertical rails along which appts. can be driven upwards or downwards inside the mast or tower.