| 摘要 |
<p>The building ventilator comprises a box-shaped housing (1) on the roof and with a top cover (2) hinging open. A ventilation aperture (7,8) hinges open at the side and allows access to the interior when the cover is shut during a rain storm. The aperture is formed in one of the vertical sidewalls (5,6) and is opened and closed by a flap (9,10).</p> |
