Roller shutter or venetian blind operating mechanism - has extruded plastics top and bottom case parts pressed to lock together

摘要

The system is used for operating roller shutters or venetion blinds. The system involves an upper case piece and lower case piece, made from plastics by extrusion. The former is thrust down over the latter, and they are pressed together, to attain a state of semi-rigid locking. The bottom end of the lower piece may incorporate belt or roller axle prongs, with an axial hole through them, and it can have top end guide lugs.