Patent ID: 7194883

Claim:
A method of hydroforming hollow work-pieces by providing a pair of upper and lower tool inserts having open axial ends and defining an elongated cavity there between when said tool inserts are forced together in a Z-direction by means of a tool punch, said upper and/or lower tool inserts being composed of at least two segments that are in a locked position relative to a base plate during the forming of the work-piece and a) providing a hollow work-piece in said cavity; b) sealing the ends of the hollow work-piece; c) filling said work-piece with liquid; d) applying an internal pressure to the inside of the work-piece by increasing the pressure on said liquid; and e) moving said upper and lower tool inserts together to deform portions of the work-piece at any time after step a), wherein said inserts are in contact with said base plate on the side opposite to the elongated cavity and movement of said segments in the X- and the Y-direction is prevented by other means than by using vertical supports acting on outer surfaces of the inserts.