| 摘要 |
PURPOSE: To provide a branch working mold, with which a branch part, the diameter of which is nearly equal to the bore of a thermoplastic resin pipe to be branch-worked, can be formed normal to the axis center line of the thermoplastic resin pipe. CONSTITUTION: A hole is made on the wall of a thermoplastic resin pipe P. Under the state that the peripheral edge part of the hole is thermally softened, a mold A, the outer diameter of the cylindrical part 2 of which is nearly equal to the inner diameter of the thermoplastic resin pipe P, is inserted in the direction, in which the outside surface of the cylindrical part 2 lies along the inner surface of the thermoplastic resin pipe P and the moved to the position, where the head part 1 of the mold A can be seen through the hole so as to engage the engaging member 3 of the mold A through a pulling-up device. Thus, by means of the pulling-up device, the mold A is turned by 90 deg. in the inside of the thermoplastic resin pipe P until the axial center line of the cylindrical part 2 becomes normal to that of the thermoplastic resin pipe P so a to be pulled up normal to the axis center line of the thermoplastic resin pipe P through the hole to form a branch part P1. |
