Extrusion die for extruding gears and method of making same

Abstract From the Canadian patent

An extrusion die for extruding helical gears or the like is formed with an extrusion passage having a predetermined draft by initially forming a blank with a central bore and frusto conical outer side surface coaxial with the bore. The formed blank is then forcibly pressed into a frusto conical bore in a die case. The frusto conical bore in the die case is tapered at an angle less than that of the outer surface of the die blank, thus when seated in the bore, radial compressive forces are applied to the blank which progressively increase in magnitude from the small diameter end of the blank to its large diameter end. While so compressed helical gear teeth are cut into the wall of the central …