AUXILIARY LADDER INSTALLING DEVICE FOR DOORWAY OF UNDERGROUND STRUCTURE

摘要

PROBLEM TO BE SOLVED: To provide an auxiliary ladder installing device excellent in installing work and restricting work of an auxiliary ladder to a receiving frame and attitudinal stability in a rising state of the auxiliary ladder. SOLUTION: A guide rod 6 is pivotally fixed to a turning arm 9 of the auxiliary ladder 4 by a first horizontal shaft 5, and a guide hole 2 for fitting and inserting the guide rod 6 and the turning arm 9 is arranged in a ladder receiver 14 of the receiving frame 1. A stopper 8 is pivotally fixed to a lower end part of the guide rod 6 by a second horizontal shaft 7, and when inserting the guide rod 6 into the guide hole 2 from above, the stopper 8 retreats to and sinks in an expanding slot part 16, and when projecting from the guide hole 2, the second horizontal shaft 7 is deviated to the center of gravity of the stopper 8 so that a tip part of the stopper 8 overhangs from the expanding slot part 16.