| 摘要 |
PURPOSE:To simplify installing work by suspending a spiral staircase from the roof inner surface of a liquid tank through an universal hinge. CONSTITUTION:An universal hinge 3 has a chain housing 3a mounted on a roof and a chain stopper 3c pivotally supported on a spherical receiving seat 3b provided on the inner surface of the housing 3a in such a manner as being capable of sliding. A spiral staircase is suspended from the inner surface of the roof 2 of a liquid tank 1 through the hinge 3, and the staircase 4 is suspended by use of a chain 5 between the hinge 3 and the staircase 4 so that the staircase 4 is more freely movable. A weigh 6 is mounted on the lower stage to increase the stability at the time of a person going up and down. Thus, the foundation of the staircase is not required, the installing steps are shortened, and the work can be simplified. |
