US Patent 7610946 Cooled turbine blade cast tip recess

A core assembly including two cores is used to manufacture a blade. The first core has an outer surface shaped to complement the tip wall bottom surface. The second core has a tip surface, a side surface, and a protrusion or a depression. The tip surface is shaped to complement at least a portion of the tip wall top surface and is configured to be disposed proximate the first core. The side surface is shaped to complement at least a portion of the side wall, and the protrusion extends from the second core side surface to contact at least a portion of the ceramic mold inner surface. In embodiments employing a depression, the depression is formed in the side surface.