At the same time the stability in the destal joint of the thermoplastics make flexible pipe at the same time the stability in the destal joint of the device null thermoplastics make flexible pipe which has the multi-stage operation phase in order

摘要

PROBLEM TO BE SOLVED: To obtain an apparatus having a multistep operation stage for forming a stable and internally normal bell-shaped mouth shape in the end joining part of a thermolastic resin pipe. ;SOLUTION: An initial inclusion part 13 having a hollow rubber element expansible until preforming a first bell-shaped mouth part and capable of being freely guided into an end part 2, a first part 11 for forming a maximaly expanded temporary bell-shaped mouth part movable from a first contraction position becoming an outer diameter of a degree capable of being freely guided into a the end part 2 to a second expansion position and having an outer diameter larger than the inner diameter of the first bell-shaped mouth part at the expansion position and a second part 12 capable of being introduced into the temporary bell-shaped mouth part expanded to the max. degree after becoming a contracted state upon the completion of the interposition of the first part and naturally contracted after the preceding expansion process to reach a final prescribed inner diameter in its inner diameter are provided.;COPYRIGHT: (C)2000,JPO