| 摘要 |
<p>Stringers and rings are made from hollow light metal profiles, the former being engaged by the latter, in a ladder, scaffolding frame, or similar. The stringers comprise a hollow profile (1) drawn from a single piece, with two closed chambers across it (2,3), of rectangular cross-section, separated by a shared partition (4). Rungs (6) only engage the interfacing chambers (3) of the two stringer profiles and are fixed in position along two parallel lateral faces (8) by cementing, welding (12) or similar, on the walling of these chambers. The two chambers are pref. of equal height and width.</p> |
