| 摘要 |
<p>The longitudinal slit for blind passage extends along the outside, open to the bottom, when a box for a roller shutter rolled up on a spindle is built into an external wall of a building along the top edge of a window opening or doorway. Its outside walling (1) is detachable. It can consist of visible cladding, or be covered in such cladding. The inner walling (2) may have a heat insulation layer on it, or consist of one. A flexible draught proof foil sheet (13) may be loosely stretched between sides, bottom and top, propped against the side of the rolled sheet. With simple construction, the inside is readily accessible for mounting, without sacrifice of insulation.</p> |
