| 摘要 |
<p>The vent discharges smoke in the event of fire in enclosed premises, and comprises one or more shutters (3) mounted on a support frame. These hinge downwards under their own weight towards the interior while the hinge end of each has an extension flange masking the corresponding side of the frame. The other sides of the shutter have ribs (10) extending towards the outside of the premises, and fitting in flanges (11) on the frame extending inwards. The shutters can be flat and rectangular.</p> |
