Ring-drum rotor

Claim 1

IN AN AXIAL-FLOW, MULTI-STAGE BLADED ROTOR: A FORWARD INTEGRAL ROTOR AND BLADE SUPPORTING MEMBER HAVING A CONICAL STUB SHAFT PORTION AND AT LEAST ONE ANNUALAR FRON DISK PORTION, SAID FRONT DISK PORTION EXTENDING RADIALLY INWARDLY AND OUTWARDLY OF THE JUNCTURE OF THE DISK AND SHAFT PORTIONS AND HAVING AN ENLARGED RIM SECTION INCLUDING A PLURALITY OF AXIAL DOVETAIL GROOVES THEREIN ADAPTED TO RECEIVE BLADES OF ONE OF SAID STAGES; AT LEAST ONE ANNULAR DISK MEMBER HAVING AN ENLARGED RIM PORTION INCLUDING A CIRCUMFERENTIAL DOVETAIL GROOVE THEREIN ADAPTED TO RECEIVE BLADED MEMBERS OF ANOTHER OF SAID ROTOR STAGES; A FRUSTO-CONICAL HOLLOW RING-DRUM PIECE COMPRISED OF A RELATIVELY THIN SHELL HAVING AN OUTER SURFACE AND AN INNER SURFACE, A PLURALITY OF CIRCUMFERENTIAL AXIALLY-SPACED DOVETAIL GROOVES IN SAID OUTER SURFACE, AND A PLURALITY OF INTEGRAL NARROW RINBG PORTIONS OF TRUNCATED GENERALLY TRIANGULAR SHAPED IN CROSS-SECTION PROJECTING FROM SAID INNER SURFACE, THERE BEING A RING PORTION AT THE LOCATION OF EACH GROOVE, WHEREIN THE INNER DIAMETER OF SAID SHELL AT SAID TRUNCATED RING PORTIONS IS SLIGHTLY LESS THAN THE DIAMTER AT THE BOTTOM OF SAID GROOVES; AND A REAR CONCIAL STUB SHAFT MEMBER HAVING A PERIPHERAL FLANGE AT ITS GREATEST DIAMETER; FASTENING MEANS CONNECTING SAID FORWARD INTEGRAL ROTOR AND BLADE SUPPORTING MEMBER TO SAID RING-DRUM PIECE ADJACENT ONE END THEREOF AND SAID REAR STUB SHAFT FLANGE TO SAID RING-DRUM PIECE ADJACENT THE OTHER END THEREOF, SAID FORWARD DISK PORTION AND SAID ANNULAR DISK MEMBER PROVIDING INCREASED RIGIDITY TO SAID RING-DRUM PIECE SHELL, WHEREIN THE CIRCUMFERENTIAL, DOVETAIL GROOVES RETAIN AT LEAST 80% OF THE STAGES OF SAID MULTI-STAGE ROTOR.