| 摘要 |
<p>A device 10 to permit ventilation of a building and is arranged to be installed from within the building and pass through a hole in a wall of the building. The device comprises a body 20 having a through aperture 22, a resilient lip member 30 located at a first end 24 of the body and arranged to engage with an outside wall of the building, a shielding means 40, 50 also located at the first end and arranged to prevent ingress of water and particles through the device, and a seal 60 located at a second end (26, Fig 5B) of the body that is opposite the first end seals the body with the hole through the wall. The resilient lip may be substantially flat ring having a diameter larger than the body and made from silicon based material. The seal may be outwardly expanded radially by rotating a locking member 70. The shielding means comprises a plurality of circular louvers (41 43, 51 53, Figs 9A & 9B) having different concentrically arranged diameters. Two sets of concentric louvers may be mounted in opposition to one another (back to back) Fig 9C.</p> |
