| 摘要 |
<p>The ladder, made of aluminium or other metal, has the rungs inserted and/or welded into two profile stringers, with improved connection. The tread surfaces (3) of the rungs are widened on both sides. The widened areas (13, 14) engage correspondingly shaped recesses or cutouts (15, 16) in the stringers (1). The rungs may be rectangular or square in cross section, with the widened areas as bulges or flanges in shape. They can be rhomboid, with the tread surfaces at an angle to the stringer axis. The rungs can have a weld seam (17) on both sides. Loading is not concentrated onto the welding alone, but spread also onto the rungs.</p> |
