To make a window shutter inexpensive by a method wherein an opening/shutting mechanism is controlled, employing a torque detecting switch.
A detecting switch 21 of a torque limiter is switched on when the torque limiter detects torque ranging above a set point. With a starting switch 14 pressed, a relay 16 is self-sustained and a motor 18 is driven. In the attached figure, an ascent/descent changeover switch 20 is shifted to the U- terminal side, and the motor 18 is driven in turning in the direction for hoisting shutter slats. As the shutter slats reach a position at the upper limit, the detecting switch 21 is switched on and the relay 16 is relieved of energy, making a relay contact 16a switched off, and the motor 18 is stopped. In the case of lowering the shutter slats with the ascent/descent changeover switch 20 shifted to the D-terminal side, the motor 18 is stopped likewise by operation of the detecting switch 21.
FUKUDA MASAAKI
SAKAMOTO OSAMU
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