Fire barrier for insertion in door - has differentially expanding blade inset in edge of laminar door to form insulating gap as temp. rises

摘要

The fire-barrier comprises a metallic blade (110) which deforms in the precense of elevated temps. and is for incorporation within the thickness of a door-panel (101). The blade has a higher coefficient of thermal expansion than the material constituting the door and is freely mounted between two fixed points (120, 121). The material expands to buckle and form an insulating air cavity between the two faces confining it. A channel (107) runs along the edge of the door to house the blade between two filler pieces (1081, 09). The channel may be formed by two assymetric 'U' sections (11, 113) which house the outer leaves (103, 104) of a door of tri-laminar construction.