| 摘要 |
<p>The doorframe for a fire-retarding door, has a Z profile in the upper part, which may be made up from two inter-locking L profiles. A flame barrier on the top horizontal part is releasable under the effect of heat to close the gap between case and door leaf. A flap (7) is hinged to the doorframe so as to swing about an axis parallel to the door breadth, towards the door leaf (6). The open end of this is fastened by connectors (8) which dissolve or are destroyed under heat, parallel to the horizontal frame piece. The flap may be made of metal, and divided into a number of independently swivelling parts. There may be several such flaps, one after the other.</p> |
