| 摘要 |
<p>A telescoping multi-sectional mast in which the upper sections (11-16) are extended and retracted in a controlled predetermined sequence. Each section, when fully extended, is automatically and positively locked to the next lower section. The improved locking system includes a lock projection-lock engagement pair. One of the pair is carried on the outer surface of each of the upper sections of the mast and the other is carried on the upper ends of each of the intermediate sections. A lock actuator stud (33) is carried on the upper end of each of the intermediate and bottom sections. This pair cooperates to restrain relative vertical movement between an upper section which is fully extended from the next lower section. An improved drive nut (22) for an axial drive screw (17) extending and retracting mast sections is located by a spring-loaded spline-seat (27) within a nut housing (23) to absorb initial shock loads when initially engaged with the drive screw. A cable tensioner/dispensing/stowage device (94) handles cables (93) extending from ground level to equipment (91) located on the telescoping mast.</p> |
