| 摘要 |
A lightweight extended aluminum or similar telescopic equilateral triangular tubular mast or tower assembly with coaxially disposed inner triangular sections and cable elevating and lowering drive apparatus for controlling low-resistance telescopic movement with alternate outside-to-inside canted pulley wheels mounted near the top of each section passing the cable downwardly and inwardly of the section to a flat pulley wheel mounted near the bottom of the next inner section.
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