| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent fluid inside a main tube from flowing out by pressing a hole saw attached to a tool attaching part onto the surface of the main tube and holding the hole saw in a hole saw holding part on the inside face of a bored tube part. SOLUTION: A branch output joint 20 is constructed of a saddle part 21, a bored tube part 22, and a hole saw 30. In the inside of the saddle part, 21, its inner circumferential face is substantially matched with the outer circumferential face of a gas main tube 40, and a branch output port 25 is arranged in the central part, while a heating electric wire 26 is buried around the branch output port 25. The saddle part 21 is fused onto the surface of the gas main tube 49 integrally by heating the electric heating wire 26. The inside face of the bored tube part, 22 is formed into a cylinder, and a recess groove 27, into which a rubber ring 28 is mounted, is arranged in the upper part of this cylindrical inside face. The inner circumferential face of the rubber ring 28 is protruded beyond the cylindrical inside face and locked on the outer circumferential face of the hole saw 30 mounted inside the bored tube part 22 so as to be held. The hole saw 30 is made of steel and formed into a cup shape provided with a hole 31 in the upper part, and its tip part is provided with a cutting edge 33 tapering cylindrically to the end part.</p> |
