| 摘要 |
<p>The lining uses plank-form jambs each side of the opening supporting a hollow sub-lintel box (8) container for roller blind drum. Each jamb is squarely rebated at the top to form a bearing seat for the drum box, also on each front edge to hide shrinkage cracks and act as an in situ shutter with an exposed face. The drum box is open on the internal face and slotted to allow blind passage and is frontally masked (1) and bears the usual lintel. The sectional assembly allows fine constructional tolerances to be achieved. For wider openings an exposed fascia beam forms a drum box and external shutter for the lintel.</p> |
