| 摘要 |
PROBLEM TO BE SOLVED: To guarantee low-resistance water flowing property of a water main to a branch pipe and facilitate its laying works in the case of fixing a non- water-suspending branch joint incorporated in a hole saw to a wall of the main, installing a boring jig in the joint, boring the wall of the main body operating the hole saw by the jig, and communication the branch pipe already connected to the non-water-suspending branch joint with the main under flowing water in the main. SOLUTION: A boring jig is so constituted that a rotational operation shaft 22 having a fitting head in relation to a hole saw 14 is penetrated through a cap member 12 which is detachable attached to one end of the trunk part 11 of a branch joint (A) formed by screwingly inserting the hole saw 14 having a blade part 141 in the trunk part of which one end of the boring jig is fixed to the pipe wall. In this case a part 222 of the rotational operation shaft 22 is threadly engaged with a a pipe part 211 of the cap member 21. |
