| 摘要 |
<p>The constructional element (1) has an upper (2) and lower (3) U-shaped member with sloping sides and outward-extending first (6) and second (7) flanges. The second pair of flanges are folded over the first (8) and the folded-over edge is crimped (9) onto the edge of the first flange. The two crimped-together members form a hollow frame member (4). The folded-over flanges form contact areas (5).</p> |
