| 摘要 |
<p>A protective cowl for roof mounted cylindrical ducts, e.g. ventilation ducts, extract ducts, is fitted to the duct by a clamp around an upper cylindrical section. The lower part of the cowl has a spreading profile, wider at the bottom, to provide shade for the seal between the roof and the duct, i.e. to protect the seal against UV exposure, where the seal is fitted up the outside of the duct. The cowl and its mounting flange are made of sheet material with a split construction with overlapping edges. A simple connection has the bottom edge of the cowl folded or crimped. The design is suitable for both flat and pitched roofs.</p> |
