| 摘要 |
<p>PURPOSE:To secure the stability of a roller by arranging a plurality of frame members and control members in a hole in the circumferential direction of the hole and connecting the members arranged in adjacent relationship in a mutually shakable state by pivot shafts. CONSTITUTION:In fixing rollers 32 in a hole 30, the lengths of control members 36 are reduced and an apparatus in a state connected in a ring shape is inserted in the hole 30. A wrench is inserted in the two-surface width part 42c of the screw rod 42 of each of the control members 36 and the screw rod 42 is rotated using the wrench. The whole is expanded by rotating the screw rods 42 and the connection parts of the respective members are pressed to the wall surface of the hole 30 and these members are strongly fixed to the wall surface of the hole 30. The rollers 32 are fixed at predetermined positions and the wire extending from the work machine in the pipe 60 extending from a manhole is trained over the rollers 32 to be capable of being guided upwardly. By this constitution, the crack of a connection part is prevented.</p> |
