Patent ID: 7337641

Claim:
A method of making a hydroformed tubular member, said method comprising the steps of: providing a tubular blank having a wall; providing a die having a first die half and a second die half with a first cavity to receive the tubular blank and a second cavity generally perpendicular to and communicating with the first cavity; disposing movable end seals in the first cavity and a movable piston in the second cavity; disposing the tubular blank in the first cavity; sealing the ends of the tubular blank with the end seals; concurrently filling the tubular blank with pressurized fluid and moving the end seals toward each other and moving the piston away from the second cavity so that a part of the wall of the tubular blank bulges into the second cavity and forms a length of tubular side wall engaging the second cavity and a dome engaging the movable piston; and moving the piston toward the second cavity, to thereby flatten the dome on the tubular blank, and thereby increase the length of tubular side wall engaging the second cavity.