Electric-powered shutter apparatus for a building opening

摘要

An electric-powered shutter apparatus to be mounted to a building. A winding drum (4) of an electric-powered shutter device (1) is provided with a driving mechanism including an electric motor (7) and a single-directional rotary clutch device (8). A balance tension device (9) is provided at the other end of the apparatus. The clutch device (8) is configured to slip when the load of the rotation in the direction of the curtain being fed exceeds a certain load. Further, the load at which the clutch device (8) slips is set so as to be greater than the force for forcibly rotating the electric motor when disconnected from electric power. The balancing tension device (9) is balanced against the sum of the weight of the shutter curtain (2) and the load for forcibly rotating the electric motor (7). Thus, the need for a braking device for the electric-powered shutter apparatus to be mounted to a building is eliminated.