To easily perform joint treatment by a simple structure by preventing small diameter drive pipes from being rolled.
The socket side engagement recessed part 24 of the forward small diameter drive pipe 7 and the plug side engagement projected part 23 of the backward small diameter drive pipe 7 are engaged with each other and driven. A joint material feed pipe 40 is buried in the small diameter drive pipe 7. The one end side inlet 41 of the joint material feed pipe 40 faces the socket 21 side end face, and the other end side outlet 42 faces the socket 19 side end face so as to communicate with the inlet 41. With the connection parts 45 of the small diameter drive pipes 7 fitted to each other from their inner peripheral surfaces by a seal means, the joint material is filled from the joint material feed pipe to the connection parts 45 through the outlet 42. Thus, the relative rotation of the small diameter drive pipes 7 can be stopped, rolling can be securely prevented from occurring, the joint material feed pipes can be easily connected to each other, and joint finishing can be securely performed.
NOBE OSAMU
Higashio Masahiro
Torii Kazuhisa