Methods are disclosed for more practical construction of liquid-cooled buckets able to efficiently transport heat energy from the inside of the airfoil skin surface in contact with hot gas to the outer surface of preformed tubes recessed into the bucket core, through which tubes liquid coolant is passed...http://www.google.com/patents/US4185369?utm_source=gb-gplus-sharePatent US4185369 - Method of manufacture of cooled turbine or compressor buckets
