Patent ID: 7628587

Claim:
A gas turbine blade shroud comprising: a platform; and one or more fins extending radially outward from the platform wherein side rails extend radially outward and along one or both edges of the platform that face the platform of an adjacent blade in a blade row and the side rails have an outer profile in the shape of a semi-circle or approximately a quarter of a circle at a radially outer end of the side rails; wherein the side rails with a semi-circular profile have a height (h) and a radius of curvature (R 1 ) where the ratio of height (h) to radius of curvature (R 1 ) is in a range from 3 to 5, and wherein there is a curved transition from the side rail to the platform and the curved transition has a radius of curvature (R 2 ) where a ratio of the radius of curvature (R 2 ) of the transition to the radius of curvature (R 1 ) of the side rail profile is in a range from 0.1 to 3.5.