| 摘要 |
PURPOSE:To enlarge the amount of pipe expansion and to correct to a true circle and to enable application to various kinds of pipes by attaching small rollers in the expander system. CONSTITUTION:By rotating and pushing-in a mandrel 6, small rollers 5 rotate with a holding board 9 and expand in the direction to expand a pipe 4. The force acting on the small rollers 5 caused by shifting of the mandrel 6 to the center of the pipe 4 can be supported by a holding rod 7, and the small rollers 5 stay at specified position of the end face of the pipe 4. Even when the small rollers 5 expand further, following-up is possible by universal joints 8. Since a rotating shaft 10 is held between to ball bearings 12, 13, the holding board 9 rotates freely with rotation in circumferential direction of small rollers 5. Pipes of different diameter can be coped with simply by changing the mandrel 6. |
