| 摘要 |
<p>The ladder has connecting rods (5) between an upper guardrail (6) and a permanent summit platform. Each rod has an upper end slidingly mounted on a corresponding lateral branch (7a) of a tubular wall plate (7) of the guardrail. The upper end of the rod is wedged to a rear end of the branch when the upper end occupies a secured guardrail maintaining position. The upper end is pushed towards front near an articulation (9) of the guardrail by pushing the rods towards front and raising the plate to allow access to the platform from bottom when the upper end occupies a temporary removal position.</p> |
