| 摘要 |
<p>1307954 Valves SOC D'ETUDES ET DE RECHERCHES DE VENTILATION ET D'AERAULIQUE 19 April 1971 [13 March 1970] 23557/71 Heading F2V [Also in Division A5] A safety valve, designed for use in ventilation ducts, comprises a spring steel shutter 2, Fig. 1, anchored relative to the housing 1 by a fastener 3, and a steel wire 5 carrying two fuse elements 6. The steel wire retains the shutter in the prestressed deformed state shown until the temperature of the air flow 7 exceeds a predetermined value whereat the fuse elements 6 melt and the shutter attains the closed position shown in broken lines. Engagement of the shutter with the housing seat 4 prevents further flow through the housing. In Fig. 3 (not shown), a respective shutter is arranged at each end of the housing so that when closed they seal the housing which thereby acts as an efficient heat insulator between the ducting. The shutter may be slightly bowed in its closed position, Fig. 2 (not shown). In another embodiment, Fig. 4 (not shown), one or a pair of shutters is anchored by a common fastener at its lower end instead of its central portion.</p> |
