| 摘要 |
A power mast for the automatic vertical elevation and retraction of various devices, such as an antenna mounted on a communications vehicle. The mast is cable-driven, having a plurality of individual telescoping sections which allow for an overall collapsed height the same as or only slightly higher than the tallest such individual section. The cable is threaded around a series of pulleys, and is driven by a motor. Constant tension is maintained in the system, so that when in its operating or "up" position, the device is held in a stable condition until retracted.
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