| 摘要 |
PURPOSE:To allow the ventilating structure of the ceiling to be formed easily in the desired size in the desired place of the ceiling in such a way as to be automatically closed at the time of a fire. CONSTITUTION:A ventilating air passage 2 communicated with the inside of the ceiling is bored in the specified place of the ceiling 1, and a ventilating fitting 3 is fittingly fixed to the ventilating air passage 2. In such structure, the ventilating fitting 3 is constituted of an inverted U-shape frame 4, supporting arms 5 and a cover body 6, and incombustible cubic expansion material 8 expanded by heat is fitted to both upper part inner side faces of the supporting arms 5. |
