Method for manufacturing a dome from an undersized blank

Abstract

Disclosed is a method of forming a dome from a substantially round blank having a surface area smaller than the surface area of the dome. The basic embodiment of the method includes the steps of shear forming the blank to form a deformed blank, spin stretching the deformed blank in selected areas along its circumference to form a stretched blank, inside spinning the stretched blank into a rough dome, and finish spinning the rough dome into the finished dome. In the preferred embodiment, the shear forming step involves coaxially securing an inside surface of the blank to a rotatable flat-nosed conical mandrel, rotating the blank on the flat-nosed conical mandrel, heating a predetermined portion of the blank, and applying a force to an outer surface of the blank such that the blank is deformed in a shape of the flat-nosed conical mandrel to shear form the deformed blank. In this embodiment, the additional spin-stretching step involves spin-stretching the deformed blank in predetermined locations to form a stretched blank having a surface area that is substantially greater than the surface area of the dome. The preferred inside spinning step involves securing the stretched blank within a rotatable concave dome mandrel, rotating the blank on the concave dome mandrel, heating a predetermined portion of the stretched blank, and applying a force to the inner surface of the stretched blank to form a dome shaped blank. Finally, it is preferred that the finish spinning step involve coaxially securing the inside surface of the dome shaped blank to a rotatable convex dome mandrel, rotating the dome shaped blank on the convex dome mandrel, heating a predetermined portion of the dome shaped blank, applying a force to the outside surface of the dome shaped blank such that the dome shaped blank is deformed in a shape of the convex dome mandrel to form the dome.

Dependencies are inferred from the claim text.