Patent ID: 7587825

Claim:
A method of forming a wheel disc comprising the steps of: forming a flat disc blank into a generally bowl shaped wheel disc defining a wheel disc axis; forming the bowl shaped wheel disc to form spoke forming regions adjacent window forming regions; forming a window in each of the window forming regions in a generally vertical direction, wherein each window has a respective outer edge proximate with a continuous outer band around a periphery of the wheel disc, wherein the windows define a plurality of spokes between adjacent windows, and wherein an angular size of each of the windows along the outer band is preferably greater than an angular size of each of the spokes; partially closing the outer band toward a cylindrical shape by engaging a cam die radially against at least a portion of the outer band, wherein the cam die comprises a slanted engagement surface having an intermediate horizontal ledge for receiving a peripheral edge of the outer band to reduce undulations of the outer band; and fully closing the outer band substantially into a cylindrical shape by axially wiping the outer band.