Protective roller shutter has slats composed of part-slats which slide against each other to open or close the slits to control light passing through while the shutter gives ventilation

摘要

The protective roller shutter structure is composed of slats (5) formed of two hollow part-slats (10,12) pushed into each other and which slide against each other at right angles to the longitudinal axis. The outer part-slat (10) grips round the inner part-slat (12) at least partially with its wide sides. Slits (7) are in the wide sides of the part-slats (10,12), which are opened and closed by the relative movements between them to allow light to pass through the shutter or not.