Electrical machining method and apparatus for forming a 3D surface contour in a workpiece with a traveling-wire electrode

A method of electroerosively forming a contour in a workpiece with a continuous wire electrode, the methods comprising the steps of:

• axially transporting said continuous wire electrode continuously from a supply means to a takeup means along a continuous path of travel to continuously renew a machining surface of the electrode;
• supporting the continuous wire electrode traveling between said supply and takeup means with guide means carried by a tool head and having an arcuate linear machining guide surface in said continuous path of travel to guide the traveling wire electrode over at least a portion of said arcuate guide surface;
• positioning said guide means on said tool head so as to juxtapose said machining guide surface with said workpiece and so as to bring at least a portion of said wire electrode over said machining guide surface into an electroerosive machining relationship with said workpiece so that said portion of the continuously traveling wire electrode provides at least a portion of said continuously renewed machining surface;
• passing an electroerosive machining current between said wire electrode and said workpiece across a fluid filled machining gap to remove material from a portion of the workpiece juxtaposed with said machining surface of the wire electrode;
• and
• relatively displacing said tool head and said workpiece in translation so that said machining guide surface effectively moves along a predetermined contouring path in said workpiece, while rotating said guide means relative to said workpiece about a rotary axis which intersects said arcuate linear machining guide surface and said portion of the wire electrode thereon, thereby forming said contour in said workpiece.