Patent ID: 7313940
Filing Date: 2008-01-01
Classification: B21D

Abstract:
1. A high-pressure system for hydroshaping a hollow workpiece having an interior, the system comprising: a lower die; an upper die vertically shiftable above the lower die between a lower closed position engaging the lower die and forming therewith a cavity shaped to hold the workpiece and an upper open position spaced above the lower die; an upper actuating element above the upper die; a vertically compressible hydraulic operating cylinder braced between the upper die and the actuating element; a spring-loaded pressure-storing cylinder having a chamber; a hydraulic line connected between the operating cylinder, the chamber of the pressure-storing cylinder, and the interior of the workpiece; means for downwardly shifting the actuating element and thereby first closing the dies together, then pressurizing the interior of the workpiece via the line from the operating cylinder such that the workpiece deforms and shapes itself to the cavity, and then filling the chamber of the spring-loaded pressure-storing cylinder, and for thereafter upwardly shifting the actuating element, whereby at first the actuating element travels upward without upward travel of the upper die as the pressure-storing cylinder empties, and then the upper die is entrained upward off the workpiece by the actuating element; and a tool mounted on one of the dies and engageable with the workpiece when the dies are closed.