Wenderoth, Lind & Ponack, L.L.P.
Method and apparatus for working tube
After insertion of a mandrel (23) into a blank tube (20) in the form of an electric welded tube, a parallel swaging operation is carried out by moving a cylindrical die (24) to cause the end of the blank tube (20) to contact tightly with a parallel forming portion (27) of the mandrel (23). After completion of parallel swaging operation, the die (24) is withdrawn out of the blank tube (20) and a push-die (33) is caused to move to the blank tube (20) from a radially outward position while leaving the mandrel (23) inside the blank tube (20) so that a weld bead on the blank tube (20) can be flattened by cooperation with the mandrel (23).
Kabushiki Kaisha Hitachi Seisakusho
B B F
B21C B21K F16F
inventional inventional inventional
Masaru Makoto
Kouyama Nishimura