Combined roller shutter case and lintel - with second inverted chamber adjacent to shutter chamber as lost formwork unit

摘要

The roller shutter case, for a window or door wall opening is in the form of a downwards open, nearly U-shaped chamber for accommodation of a roller shutter. A second chamber (3) is open upwards at the side close to the roller shutter chamber (2) and running parallel to it. This forms a lost formwork unit for a concrete lintel, of load bearing type, to be fitted at the side close to the roller shutter case. One bounding wall of the shutter chamber forms a partition (4) between the two chambers. The upwards open chamber is wider than the thickness of the boundary walls of (4, 5, 6) of the two chambers. Both chambers may be virtually U-shaped in cross-section, with their combined cross-section making a horizontal S shape.