| 摘要 |
<p>Rolled up lengths of film, fixed along one long edge, can be unrolled by means of cables supported in the structure, into a posn. in which they provide heat insulation. Similarly they can be rolled back into a non-insulating posn. When two rolls of film are to be unrolled in opposite directions their fixing edges are joined together. Elements such as cables are tensioned between supports and run at right angles to the long axis of the qreenhouse, and at least one additional roll of film is provided to cover a side wall and its cables are linked to those of the other rolls. In the inactive posn. the reels form only a very slight obstruction to the passage of light, and being light in weight they are easily and quickly manipulated.</p> |
