| 摘要 |
<p>The fireproof door (100) for inspection and maintenance openings in ceilings and walls has a fireproof frame (2) made of fire-resistant material which is fitted in a horizontal ceiling or vertical wall (9) and frees a fireproof opening. The fireproof frame is formed with at least one step (25) along the edges (21) and/or the corners of the opening, or at two oppositely-disposed points facing the room (RS) and projecting towards the fireproof opening.</p> |
