Bladed rotors of machines such as gas turbines

Claim 1

A BLADED ROTOR COMPRISING (A) A ROTOR DISC HAVING A PERIPHERAL PORTION WITH AXIALLY-FACING SURFACES, (B) A RING OF BLADES CARRIED BY THE PERIPHERAL PORTION OF THE DISC, EACH BLADE HAVING, (C) A ROOT INTERENGAGING WITH THE PERIPHERAL PORTION OF THE DISC TO RETAIN THE BLADE RADIALLY IN POSITION, THE ROOT HAVING AXIALLY FACING SURFACES CORRESPONDING TO THE AXIALLY-FACING SURFACES OF THE PERIPHERAL PORTION OF THE DISC, (D) A CIRCUMFERENTIAL GROOVE IN ONE OF SAID AXIALLYFACING SURFACES OF THE PERIPHERAL PORTION, SAID GROOVE AFFORDING BY ITS SIDES A RADIALLY OUTWARDLY FACING SURFACE AND A RADIALLY INWARDLY FACING SURFACE SPACED OUTWARDS FROM THE OUTWARDLY FACING SURFACES, (E) A SERIES OF ANGULARLY-SPACED FIRST DOGS ON SAID PERIPHERAL PORTION, SAID FIRST DOGS PROJECTING RADIALLY OUTWARDS FROM THE OUTWARDLY FACING SURFACE OF SAID GROOVE IN AXIALLY SPACED RELATION TO SAID PERIPHERAL PORTION, (F) AT LEAST ONE KEY HAVING A SURFACE ENGAGING SAID OUTWARDLY FACING SURFACE OF SAID GROOVE, SAID KEY FURTHER HAVING CIRCUMFERENTIALLY-SPACED END PORTIONS EACH EXTENDING BETWEEN ONE OF AN ADJACENT PAIR OF SAID FIRST DOGS AND THE PERIPHERAL PORTION OF THE DISC, SAID KEY FURTHER HAVING A RADIALLY OUTWARDLY FACING SURFACE SPACED INWARDLY FROM THE RADIALLY INWARDLY FACING SURFACE OF SAID GROOVE, (G) A TAB ON SAID KEY PROJECTING AXIALLY BETWEEN AND ABUTTING CIRCUMFERENTIALLY AGAINST THE SAID PAIR OF FIRST DOGS, AND (H) AN ANNULAR UNSPLIT PLATE EXTENDING IN CONTACT WITH THE AXIALLY-FACING SURFACE OF SAID PERIPHERAL PORTION AND SAID BLADE ROOTS, SAID ANNULAR PLATE HAVING A CIRCUMFERENTIAL LAND PROJECTING AXIALLY THEREFROM INTO SAID CIRCUMFERENTIAL GROOVE, SAID LAND HAVING A RADIALLY OUTWARDLY FACING SURFACE IN CONTACT WITH THE RADIALLY INWARDLY-FACING SURFACE OF SAID GROOVE AND A RADIALLY INWARDLY-FACING SURFACE IN CONTACT WITH THE RADIALLY OUTWARDLY-FACING SURFACE OF SAID KEY, SAID ANNULAR PLATE FURTHER HAVING CIRCUMFERENTIALLY SPACED SECOND DOGS ENGAGING AXIALLY IN THE SPACES BETWEEN THE SAID FIRST DOGS AND THE PERIPHERAL PORTION OF THE DISC, AND SAID ANNULAR PLATE FURTHER HAVING A RADIAL NOTCH THEREIN DEFINING A PAIR OF OPPOSED CIRCUMFERENTIALLY-FACING SHOULDERS, SAID TAB HAVING A PORTION ENGAGING IN SAID NOTCH AND ABUTTING SAID OPPOSED CIRCUMFERENTIALLY-FACING SHOULDERS.