| 摘要 |
<p>PROBLEM TO BE SOLVED: To make a joining work easy and to obtain reliable adhesiveness with less adhesion area by providing a spigot on an outer periphery on one end side of a tube, providing a socket on an inner periphery on the other side and forming a series of a plurality of annular locking parts having tapered parts and hook step parts on these spigot and socket. SOLUTION: In the case that this structure is applied to a structure of a joining part of a tubular body suitable for a drawing method of construction of a cable protective tube, a spigot 3 having a hitting step part 2 is provided on an outer periphery on one end side of a tube 1 and a socket 5 having a hitting step part 4 is provided on an inner periphery on the other end side. A series of plural steps of each of annular locking parts 8, 11 having large diameter and small diameter tapered parts 6, 9 from an opening edge to the depth and vertical hook step parts 7, 10 on depth tip sides of the tapered parts 6, 9 are formed. When the tube is connected, each step part 7, 10 of the annular locking parts 8, 11 of one tube and the other tube each other are surely engaged and thereby a joining work is made easy and sure joining is obtained.</p> |
