| 摘要 |
The cover (4) comprises a frame (6) which surrounds a wall apetuaperture, with a cover plate or sheet (5) covering the surface within the frame. The cover is temporarily pressed against a wall (1) with the frame surrounding the hole to be covered, and has an air permeable part for ventilation purposes. This part is pref. formed by an elastic packing (8) along the cover edges, locating against the wall. The packing is made of porous, air permeable material with such elasticity that (when the plate is pressed against the wall) it compensates uneven surfaces on the wall itself. |
