Foldable ladder for use with swiveling trap door, has three parts including posts and stairs and foldable on each other through articulation unit, where widths of stairs are equal to or greater than widths of posts

摘要

The ladder has three parts (2-4) with longitudinal posts (6) and stairs, and foldable on each other via an articulation unit, where the widths of the stairs are equal to or greater than the widths of the posts. The stairs pass partly from same side (C1) of the posts in upper part end and pass partly from a side (C2) or side (C1) of the posts in a lower end part. The stairs are intercalated in a folded position. An independent claim is also included for an installation including foldable stairs.