Patent ID: 7614270

Claim:
A method of forming a workpiece comprising the steps of: providing a forming apparatus, the forming apparatus having an upper die member, a punch and a blank holder, the upper die member having a cavity, the punch having a forming surface and the blank holder operative to move between a first, open position and a second, closed position; placing a workpiece between the upper die member and the blank holder when the blank holder is in the first, open position; moving one of the upper die member and the blank holder to place the blank holder in the second, closed position thereby sandwiching the workpiece between the upper die member and the blank holder; moving the workpiece sandwiched between the upper die member and the blank holder against the punch such that the punch engages the workpiece and draws a portion of the workpiece sandwiched between the upper die member and blank holder into the cavity in the upper die member; supplying gas pressure to the cavity wherein the gas pressure acts against one side of the workpiece to press the workpiece against the forming surface of the punch until forming of the workpiece is completed; withdrawing the punch; and moving the upper die and blank holder to the first, open position and removing the formed workpiece.