| 摘要 |
<p>The compact connection for ventilating ducts uses a plastics sheet (1) which is welded at both ends to the inside of a plastics frame. This frame is made from angle section material (2, 3) which is reinforced by a further angle section frame (6, () which fits inside it. The edges (4, 5) of the angle (2, 3) of the first frame are bent over the edges of the angle (6, 7) of the second frame. The outside face of the vertical arm (2) of the first angle incorporates a sealing rib (8) which projects outwards at an angle. At the cornes, the first angle is cut, leaving the corners of the second angle projecting the latter incorporating bolt holes.</p> |
