Patent ID: 6053023
Filing Date: 2000-04-25
Classification: B21J,B21K

Abstract:
A method of cold forging a workpiece having a non-circular opening, the method comprising the steps of:(a) upsetting the workpiece;(b) backward extruding the workpiece;(c) piercing the workpiece; and(d) coining the workpiece to form a non-circular opening in the workpiece by using a press, the press including a punch stool for supporting the workpiece, a filler plate for supporting the punch stool, a punch, a punch holder for supporting the punch, an upper outer coin insert for engaging an upper portion of the workpiece, an upper inner coin insert for engaging the upper portion of the workpiece, and a lower coin insert having a non-uniform diameter, the non-uniform diameter of the lower coin insert is such that a diametric length along a longitudinal axis is smaller than a diametric length orthogonal to the longitudinal axis.