Patent ID: 7387494

Claim:
A rotor wheel for a turbine comprising: a plurality of fingers spaced axially one from another and extending circumferentially about a margin of the wheel for receiving fingers of buckets; said wheel fingers including a plurality of circumferentially extending sections of successively reduced axial extent in a radial outward direction; each of said wheel fingers having fillets at transitions between radially adjacent sections; each wheel finger fillet being comprised of first and second radii with the first radius having a larger radius than the second radius; and wherein axially adjacent wheel fingers at radially innermost locations along the wheel margin define a bottom of a generally dovetail-shaped slot between the adjacent wheel fingers, the bottom of said slot having a pair of fillets with each bottom slot fillet comprised of first and second radii with the first radius of each bottom slot fillet having a larger radius than the second radius thereof, wherein the bottom of said slot includes a flat extending axially and circumferentially between the second radius of each of said pair of bottom slot fillets.