Patent ID: 7909570

Claim:
An interturbine duct, baffle and seal arrangement adapted to be mounted between first and second adjacent turbine stages of a gas turbine engine, comprising inner and outer flow path containing walls adapted to contain hot combustion gases therebetween, and a baffle integral to the inner flow path containing wall, said baffle defining a boundary of an inter-stage cavity behind the first turbine stage, the baffle having a radially inwardly extending distal end portion having a radially inwardly facing edge juxtaposed to a radially outwardly facing surface of a seal runner, wherein the radially inwardly extending distal end portion of the baffle forms a knife edge seal which cooperates with the seal runner to seal the inter-stage cavity, the inwardly facing edge of the baffle is itself the knife edge, the knife edge and the baffle being a one-piece sheet metal component, thereby performing a sealing function to the arrangement.