| 摘要 |
PROBLEM TO BE SOLVED: To dispense with electric power and a special holding member in holding a brake in a released state during the own-weight descent of a shutter curtain in an automatic closing device for releasing the brake on the basis of a signal from fire alarm equipment to allow the shutter curtain to descend of its own weight. SOLUTION: This automatic closing device 15 is provided with a short circuit C for short-circuiting a DC geared motor 17 to make dynamic braking on the basis of detecting a brake in the released state.
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