| 摘要 |
<p>The door partic. for fire protection has a glazed frame and a leaf hinging a door frame, both leaf and frame being of steel angle. Leaf and/or door frame consist of internal (18, 10) and external (17, 5) casings spaced apart, and welded together via connecting bars. These can be of round section (4), mounted at intervals between inner and outer casings and welded to both. The connecting bars can be arranged in rows, those in one being offset from those in the other. The intermediate casing can be of steel angle or flat perforated steel.</p> |
