| 摘要 |
Foldable or retractable ladder, especially for use at an opening in the ceiling, for example, to an upper storey such as an attic in a building or the like, which ladder comprises a plurality of sections (11, 12, 13) arranged in operative position of the ladder, in such a manner, that the upper section (13) of the ladder by hinge members (15) is pivotally attached to a frame (14) for the door opening, and the folding-down movement of the ladder is limited by a toggle joint arrangement (16, 17) attached to the upper section (13) of the ladder. The toggle joint arrangement consists of two toggle joints attached to each side of the frame and, respectively, each side rail of the ladder and interconnected at the ladder by means of an axle (18) extending in parallel with the runs. |
