| 摘要 |
PROBLEM TO BE SOLVED: To eliminate an unstrained portion of a chain when a garage entrance is opened. SOLUTION: A chain holder 7 which is rotatable in a vertical plane and capable of self-resetting is linked to a hollow columnar body 2 via a second rotational axis 8, and has its end 7b made in contact with a chain 1 from below. When the chain 1 is in a strained state, the end 7b is arranged at a predetermined location separate from the hollow columnar body 2. When the chain 1 is delivered, the strained chain 1 is held as it is, and the chain 1 delivered from the hollow columnar body 2 via a passing port 3 is not moved beyond the end. Therefore, the chain 1 is slacked off between the end and the passing port 3, and when the total weight of the chain 1 positioned outside the hollow columnar body 2 reaches a predetermined weight, the chain holder 7 is overturned, which releases the chain 1 held by the end on the fixed end side all at once. On the other hand, when the chain 1 is housed, the chain performs self-resetting according to the housing of itself.
|
