| 摘要 |
PURPOSE:To enable a device to correspond to a change of bore size of a pipe, by urging a chassis, which supports a caterpillar belt, in a direction of separating from each other by a resilient member, in the case of the in-piping running device having three running units coming into contact with an internal wall of the pipe. CONSTITUTION:A chassis 1 curves both end parts of a rectangular plate forming a connection part 2 further its end part forming a flange 3. The chassis 1 arranges each longitudinal three sheets so as to place a line, connecting end parts of each chassis, on a chord of the same circle, and between the neighboring connection fellow parts 2 of the chassis 1, a hinge 5, which internally mounts a coil spring 4, is mounted to the inside of the connection part 2 through a bolt. While a hinge 7 with no coil spring, being fixed by a bolt to the side end of the connection part 2, is provided in the outside of the connection part 2. The chassis 1 is urged so as to separate from each other by the spring 4 of the hinge 5. |
