SHUTTER CURTAIN RAISING PREVENTION DEVICE IN SHUTTER DEVICE

摘要

PROBLEM TO BE SOLVED: To secure crime-prevention effect by preventing a shutter curtain from being raised even if the shutter curtain is forcibly raised from the lower surface of a seat plate by using a tool such as a bar in a closed shutter. SOLUTION: This shutter curtain raising prevention device comprises a first control means stopping the lowering of the shutter curtain and restricting the self-weight lowering of the suspended shutter curtain when the lowermost part of the shutter curtain touches a floor surface at the closed position of a building opening part and a second control means releasing the restriction of the self-weight lowering of the shutter curtain 3 based on detection signals when the raising of the lowermost part of the shutter curtain 3 by an external force is detected after the full closing operation of the shutter curtain is normally performed by the first control means. COPYRIGHT: (C)2005,JPO&NCIPI