US Patent 9447692 Turbine rotor blade with tip cooling

A turbine rotor blade with a main serpentine flow cooling circuit extending from a leading edge region to a trailing edge region, and a mini serpentine flow cooling circuit in the blade tip region connected between the first and second legs of the main serpentine flow circuit. Exit slots in the trailing edge region are connected to the last leg of the main serpentine flow circuit and to the mini serpentine flow circuit to provide cooling for the trailing edge region.