Foothold for opening installation

摘要

(57) Abstract Objective In the opening of the land which forms the entrance of the subterranean hole installationBeing re ru foothold, according to job unnecessary of the aforementioned openingThe part is closed, position of the part which among of the particular openings opensWith those which can change size easily are offered. Constitution It was laid out outside opening 1 the guy dough which opposesOn oru 2, the applying which consists of the channel it transfers material 3Two bodies it laid out parallel. Both it is required and transfers on top between material 3 twoFoothold board 5 was engaged slide possibly. Foothold board 5 is applied, crossing overTo do and make slide vis-a-vis material 3, between both foothold board 5 necessary in jobOpening 1 substantial main point by making the opening W _A, smallThe fence it can make easy to do.