| 摘要 |
A fire damper which is intended for being mounted in a ventilation duct for automatically cutting off the latter in case of fire, has a retainer part 1 which is intended for being fastened on the ventilation duct and has cutouts 7 situated right opposite each other. A flap 8 is swingably arranged in the retainer part 1 by means of two axle journals 9 which are journalled in the cutouts, and is swingable between an open and a closed position. Normally, an easily fusible wire 10 keeps the flap 8 in an open position. In case of fire, the wire 10 melts and releases the flap 8, which is thereby, by means of a weight 12, swung into a closed position. The axle journals 9 have an elongate cross sectional form, and each cutout 7 essentially has the form of a bow. Said bow has an upper portion defining the open position of the flap 8, a lower portion defining the closed position of the flap 8, and a third, intermediate portion, along which the journal 9 is slidable from said upper to said lower portion. The bow is formed in such a way that it imparts to the journal 9 a twisting movement during its sliding therein. <IMAGE> |
