Fire door with foam plastics core - is sandwiched between steel plates with edges bent inward and engaged by outwardly inclined flanges of U-section members

摘要

The metal fire door comprises a foam plastics core (2) sandwiched between two steel plates (1). The plates are connected at least along the two longer door edges. The edge portions (3) of the plates are folded inwards over more than 90 deg. (alpha, round 135 deg.) to form inwardly open V-section grooves (4) which are engaged by the outwardly inclined flanges of a U-section (steel) member(5). - Along each door edge, the outwardly diverging channel formed by the member (5) is covered by an inwardly converging channel formed by the member (5) is covered by an inwardly converging section (aluminium) cover strip (6). The strip is secured to the member by spaced e.g. self-tapping screws (7).