US Patent 7413403 Turbine blade tip cooling

A turbine engine blade has an attachment root, a platform outboard of the attachment root, and an airfoil extending from the platform. The airfoil has pressure and suction sides extending between leading and trailing edges. An internal cooling passageway network includes at least one inlet in the root and a plurality of outlets along the airfoil. The passageway network includes a leading spanwise cavity fed by a first trunk. A streamwise cavity is inboard of a tip of the airfoil. A spanwise feed cavity feeds the streamwise cavity absent down-pass. A second trunk feeds the spanwise feed cavity.