Frame for a roller blind fitted with mechanisms capable of automatically closing the blind which protects a window or a french window

摘要

A frame comprises a first roller shutter box (1) housing a take-up roller (2), and a second roller shutter box (3) wherein a shaft (4) turns; a first elastic mechanism (5) rotates the take-up roller (2), while a second elastic mechanism (6) rotates the shaft (4); the take-up roller (2) stretches a blind (7) which is drawn between the take-up roller (2) and a manoeuvring bar (8) sliding on two guides (9,10); two pulleys (11,12) are splined to the ends of the shaft (4) for manoeuvring two tie rods (13,14) connected to the manoeuvring bar (8); the tie rods (13,14) are located inside the respective guides (9,10) for transmitting the tensile stress of the second elastic mechanism (6) to the manoeuvring bar (8); this stress prevails on the stress of the first elastic mechanism (5), therefore the blind (7) closes the French window when only the stresses of both elastic mechanisms (5,6) are applied to the blind (7).