| 摘要 |
A multi-stage extensible tower on a wheeled base with a platform at the top has an extensible multi-sectioned ladder which slopes downwardly uniformly from the platform when the tower and ladder are in extended position. When the tower and ladder are in lowered, retracted position, the ladder sections have different slopes from one another. Outriggers are provided on the base which have a retracted position preventing extension of the tower. The platform has a fence which can be swung down level with the platform for conditions of reduced overhead clearance while the unit is being moved. |
