Patent ID: 7810367

Claim:
A method for shaping a hollow metallic workpiece, said method comprising the steps of: providing a mold tool having a shaping cavity defined therein wherein in the use of said mold tool, a workpiece is shaped in said shaping cavity; said mold tool further including a heater which heats at least a portion of the mold tool so that a workpiece which is disposed in said mold tool is heated thereby, said mold tool further including a neutral cavity wherein in the use of said mold tool no significant shaping of a workpiece takes place in said neutral cavity; providing a hollow, metallic workpiece; disposing said workpiece in said mold tool so that a first portion of the length thereof is disposed in said shaping cavity, a second portion of the length thereof is disposed in said neutral cavity, and a third portion of the length thereof projects from said mold tool wherein said second portion is disposed between said first portion and said third portion; activating said heater so as to heat said at least a portion of said mold tool whereby said mold tool transfers heat to said second and/or third portion of said workpiece; pressurizing the interior of said workpiece; applying an axially directed compressive force to said third portion of said workpiece so as to bias said third portion towards said first portion; and maintaining said third portion of said workpiece at a temperature which is less than the temperature of said first portion of said workpiece during the time said workpiece is pressurized so that said pressurization does not deform said third portion.