摘要 |
A method of expanding a tube into engagement with a header wherein the expander is permitted to move longitudinally a predetermined amount relative to the tube while the expander is being rotated and expanding the tube into engagement with the header. The tube expanding apparatus includes a rotatable expander for insertion into the tube to be expanded, a stop collar that engages the header, a thrust collar that is fixed relative to the expander and a spring disposed between the stop collar and thrust collar permitting the thrust collar and expander to move relatively into the tube as the expander is rotated. |