| 摘要 |
PROBLEM TO BE SOLVED: To provide a falling restricting sensor construction for a sheet shutter capable of definitely avoiding a contact between the sheet and a passing body and also properly preventing erroneous operations and positioning the detection area of the sensor as close as possible to the sheet side even though the shutter is flapped by a wind and its core material is bent during the falling operation of the shutter. SOLUTION: A sheet-shaped shutter 2 is installed in a rising and falling manner along a gate-shaped frame 1a by normal and reverse rotation drive of a drive motor 3, a falling restricting sensor 4 for detecting the presence of a passing body is provided below the frame 1a, a plurality of a first falling restricting sensor 41 and a second falling restricting sensor 42 or the like are arranged up and down in a row, which detect passing bodies at every different points of height of the sheet shutter restricting the falling of the sheet shutter 2 when the falling restricting sensor 4 has detected the presence of the passing body; and when the shutter 2 falls and passes the detection height of each sensor, the detection operation of each sensor is sequentially canceled and the state of non-detection is created by the falling restricting sensor construction of the sheet shutter.
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