| 摘要 |
PROBLEM TO BE SOLVED: To provide a cut-off device for a ventilation hole of an underground facility, having a relatively simple structure, capable of sufficiently securing an aperture area of a ventilation hole aperture and air-tightly sealing the aperture when each water stop is closed.SOLUTION: A plurality of water stops 6 are juxtaposed at predetermined spaces in an aperture 3 of a ventilation hole 1, and an auxiliary frame 12 for closing a clearance between the adjacent water stops 6 is swingably provided. A watertight rubber 14 is adhered to a lower face side of the auxiliary frame 12 while a convex part 15 for engagement with a frame body 10 is protruded on an upper face side of the auxiliary frame 12, the lower face side of the auxiliary frame 12 is locked to a water stop end edge part 6a so as to rotate in subordinate manner according to undulation movement of the water stop 6, and a concave part 16 engageable with the convex part 15 of the auxiliary frame 12 is provided on a lower face side of the frame body 10. When horizontally raising each water stop 6, the convex part 15 of the auxiliary frame 12 engages with the concave part 16 of the frame body 10 and the auxiliary frame 12 is horizontally supported. Then, the watertight rubber 14 on the lower face side of the auxiliary frame 12 abuts water-tightly to the water stop end edge parts 6a on both sides thereof, respectively. |
