| 摘要 |
<p>The frame (1) is for use in ventilation systems. It is fitted closely or remotely in relation to the protected wall or ceiling . It consists of a guide sector surrounded by a fitting part, and consists of at least two shaped pieces (5, 6), by which the guide sector is enclosed, i.e. they form a frame round it. There may be a through aperture (7) with a shaped surface (8) to conform to the external shape of the guide sector.</p> |
