| 摘要 |
PROBLEM TO BE SOLVED: To provide a rapid-fall stop device for a shutter for a building capable of improving its reliability and durability in operation and reducing the number of parts to miniaturize it and reduce its cost. SOLUTION: This rapid fall stop device 10 is provided with a boss 11 mounted on a drum shaft to rotate integrally, a casing 12 surrounding the outer periphery of the boss, a brake member 21 coming into contact with an inner peripheral face of the casing to generate braking force, a spring for energizing in the direction of counterbraking, an operation member 33 mounted on an outer peripheral face of the boss to rotate and be displaced relatively between two positions, allowing the brake member to leave and be separated from the inner peripheral face of the casing and be positioned at a first position by spring force, and bringing the brake member 21 into contact with the inner peripheral face of the casing against spring force at a second position, an annular member 32 in which rotation force is transmitted from the operation member through a torque limiter 40, and a resistance force generating means 34 for bringing an annular member side element into contact with a casing side element by centrifugal force to generate rotation resistance force when a winding drum rotates abnormally due to rapid fall of the shutter. COPYRIGHT: (C)2008,JPO&INPIT
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