| 摘要 |
PCT No. PCT/SE83/00459 Sec. 371 Date Aug. 1, 1984 Sec. 102(e) Date Aug. 1, 1984 PCT Filed Dec. 15, 1983 PCT Pub. No. WO84/02554 PCT Pub. Date Jul. 5, 1984.A telescopic mast comprises a plurality of mast sections (2, 3, 4) which can be displaced axially relative to one another while guided by each other. The sections are arranged to be moved out of one another by means of a continuous line (13), which passes and co-acts with all mast sections, from the outermost to the innermost section. Each mast section (2, 3, 4) includes at least one lower line-guide pulley (5, 6, 7) and one line-returning unit (8, 9, 10) arranged at the upper end of a respective section. That part of the line (18) extending between the pulley (5) and the line-returning unit (8) of one section (2) and between said line-returning unit (8) and the guide pulley (6) of the nearest inwardly lying section (3) is fully protected in a space located between the sections (2, 3). The sections suitably comprise open-ended, closed-wall cylinders (2, 3, 4) arranged to fit within one another with a small clearance therebetween and which enable the mast to be used in the absence of guys. |
