| 摘要 |
<p>The rof superstructure is designed to support part-cladding elements esp. slates, and uses interlocking rafters (1) and battens (4) of a folded galvanized metal sheet construction, interlocking being effected by an elastic "snap on" connection of the battens to the rafters. The rafters may be of a square 'U' section with trapezoidally undulating flange edge profiles, the peaks (3) in the respective edges being directly opposite one another. Symmetrical trapezoidal notches (2) are provided in each peak, having a single rising step (2c) in each of their inclined edges. Battens may be of a trapezoidal inverted channel section, having an acutely angled external return (4b) to each flange.</p> |
