Fire-barrier for ventilation ducts, with connecting piece in frame

摘要

The connecting piece (2) inserted into the frame contains two swivel-mounted pivot flaps (3a,3b) held in an open position under spring tension by a fusible plumb-bob (4). After the plumb bob has melted at a pre-set temperature, the pivot flaps are forced to shut and block off the cross-section of the connecting piece. The connecting piece has at least one Z-shaped cross-sectioned sprung bracket (5) protruding beyond its front edge (2a). The brackets grip behind a stop piece over which each sprung bracket travels as the connecting piece is inserted.