| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a movable ladder that can be installed easily in a utility tunnel without disturbing the passing of operators and the work, even when there is no space for a ladder to be stored in the upper side of a utility tunnel entrance such as in a shaft, and that eliminates the need for maintenance of high-place work in the utility tunnel. <P>SOLUTION: In the lower end 112a of a supporting column 112 in a ladder body 110 comprising a pair of supporting columns 112 and 114 and a plurality of treads 116 therebetween, a rotation part 120, disposed on the floor 10a of a utility tunnel 10, is installed to support the supporting column 112 in a freely turnable manner mainly at the axis parallel to the extended direction of the ladder body 110. The supporting column 112 is fixed to the wall surface of the utility tunnel 10 in a freely turnable manner at the same axis as the above-mentioned axis through a hinge part 130. <P>COPYRIGHT: (C)2012,JPO&INPIT |
