| 摘要 |
<p>An electrically-driven closure apparatus for building includes the following parts: a shutter curtain, a driving device for driving the shutter curtain to open and close an opening by forward and backward driving power of an electric motor, the driving device being rotationally displaceable forward and backward relative to a fixed part in accordance with load applied thereto; a forward load detecting spring disposed between the driving device and a fixed member or the frame, so as to produce force which resists forward rotational movement of the driving device; a backward load detecting spring disposed between the driving device and a fixed member or the frame, so as to produce force which resists backward rotational movement of the driving device; and sensors for detecting the rotational displacements of the driving device. Spring constants of the forward and backward load detecting springs are independently adjustable.</p> |
