Method and means for braking and reversing a gas turbine rotor

Claim 1

IN A GAS TURBINE ENGINE, A ROTOR HAVING A PLURALITY OF CIRCUMFERENTIALLY SPACED BLADES DESIGNED TO BE DRIVEN IN A FORWARD ROTATIONAL DIRECTION ABOUT THE AXIS OF ROTATION OF SAID ROTOR BY AXIAL FLOW OF MOTIVE GASES PAST SAID BLADES, GAS PASSAGE MEANS ARRANGED COAXIALLY WITH SAID ROTOR FOR CONDUCTING SAID MOTIVE GASES PAST SAID BLADES IN DRIVING RELATIONSHIP THEREWITH, ADJUSTABLE NOZZLE MEANS IN SAID GAS PASSAGE MEANS UPSTREAM OF SAID BLADES FOR SELECTIVELY VARYING THE ANGLE OF ATTACK OF SAID GASES AGAINST SAID BLADES, SAID NOZZLE MEANS BEING ADJUSTABLE IN A REVERSING DIRECTION FOR DIRECTING SAID MOTIVE GASES AGAINST SAID BLADES TO IMPART A REVERSE THRUST TO SAID BLADES URGING THE LATTER IN A REVERSE ROTATIONAL DIRECTION OPPOSITE SAID FORWARD DIRECTION, NORMALLY CLOSED EXHAUST PORT MEANS ARRANGED IN SAID PASSAGE MEANS AROUND THE PERIPHERY OF SAID BLADES AND BEING OPENABLE TO EXHAUST SAID GASES RADIALLY FROM SAID BLADES, AND MEANS FOR OPENING SAID PORT MEANS CONJOINTLY WITH ADJUSTMENT OF SAID NOZZLE MEANS IN SAID REVERSING DIRECTION.