System for operating a plain blind

A system for operating a blind (112) inside a chamber (5, 150) enclosed by panes (6, 7) surrounded by a frame (15), the frame comprising side hollow bars (20, 30, 35) connected by corner pieces (40, 50, 60), the system comprising:

• a blind-roller (113) supported inside said chamber (5, 150), wherein a first end of the blind (112) is fixedly connected to the blind roller (113);
• a kinematic mechanism placed inside an oblong body (65) fixed to a corner piece (60), wherein said mechanism includes three mutually engaged pinions (78, 79, 80), a first pinion (80) of which axially connected to the blind roller (113);
• and
• a first box (136) supported inside said chamber (5, 150) fixedly to a first end of the frame (15);
• wherein said blind (112) comprises:
• first pulling means (153) supported inside said first box (136), the first pulling means including a helical spring (154) wound around a spring-roller (157) axially connected to a second pinion (78) of the kinematic mechanism by the interposition of an intermediate idle third pinion (79);
• second pulling means (173), comprising:
• a mobile bar (120) fixedly connected to a second end (111) of the blind (112);
• a second box (184) supported inside said chamber (5, 150) fixedly to a second end of the frame (15) opposite to a first end of the frame;
• a cord (180) having one end fixed to a center of the mobile bar (120) and a second end fixed to a cord-roller (198) supported inside the second box (184);
• a first pin (217) axially engaged with a first end of the cord-roller (198) and orthogonally engaged by a fourth pinion (103) and worm screw (100) with a shaft (104) of a first magnetic disk (98) disposed within the second box (184) and matching with an internal surface of the pane (6) of enclosed chamber (5, 150);
• and
• a threaded bushing (225) fixed to a second end of said cord roller (198) that screws into a threaded bar (224) fixed to the frame (15) for translating the said cord roller (198) axially to accommodate turns (202) made by said cord (180);
• and
• a second magnetic disk (12) rotated by external operating means and matching, at the position of the first magnetic disk (98), with the external surface of the pane (6) of the enclosed chamber (5, 150).