Cooled turbine blade

Claim 1

A turbine blade adapted to be mounted in radially projecting relationship on a turbine rotor, said blade comprising an outer cambered airfoil portion formed with a thin wall and tip end wall defining an internal cavity, a single dovetail tang integral with the inner end of said airfoil portion and generally aligned centrally therewith and having a curvature approximating the camber of the airfoil portion, said tang having a passageway extending radially therethrough from the bottom surface thereof to said cavity, a thin-walled, hollow insert insertable through said passageway and extending from the lower end of and through said passageway, into said cavity and terminating adjacent said tip end wall, said insert having an inlet in its lower end for the admission of cooling air to its interior, said insert having a multiplicity of relatively small holes therethrough which are directed toward surfaces defining said cavity, and impinge cooling air thereagainst, said insert being loosely assembled within said tang passageway and thereby removable therefrom and also including a flange at its lower end engageable with the bottom of the tang to position the insert in a radially outward direction relative to said blade, and means for discharging cooling air from said cavity.