| 摘要 |
<p>A substantially C-formed sheet metal profile has a continuous substantially zig-zag formed groove in its web. According to one embodiment of the invention, (Fig 1), the groove (16-19) is a serpentine groove. According to an other embodiment (Fig 5) the zig-zag groove (26, 27) has straight diagonal grooves that join with two longitudinal grooves (24, 25) in a lattice-like pattern. The illustrated profiles will have an improved stiffness.</p> |
