Patent ID: 7641446

Claim:
A turbine blade for a gas turbine engine having an axis from an intake of the engine to the exhaust of the engine, the turbine blade extending in a radial direction from the axis, the turbine blade comprising: an aerofoil including a high-pressure surface, a low pressure surface, a leading edge, a trailing edge, a root portion and a tip surface extending between the high and low pressure surfaces; and an air leakage restricting member on the tip surface, the air leakage restricting member being configured to substantially prevent leakage of air over the tip surface, wherein the leading edge curves from the root portion to the tip surface, in a direction that is substantially tangential to the axis of the engine, and the trailing edge is substantially straight, wherein the curvature of the leading edge increases from the root portion to the tip surface, and wherein the air leakage restricting member comprises a high pressure surface and a low pressure surface, extending between a leading edge of the air leakage restricting member and a trailing edge of the air leakage restricting member, at least a portion of the high pressure surface being one of substantially planar and convex and at least a portion of the low pressure surface being one of substantially planar and concave.