Over-speed shut-off mechanism for turbines and the like

Claim 1

IN A FLUID PRESSURE MEDIUM OPERATED TURBINE, THE COMBINATION OF A CASING SECTION FOR HOUSING A TURBINE ROTOR; A CONCENTRIC ANNULAR CASING SECTION AT ONE SIDE OF SAID ROTOR CASING SECTION; A VALVE ON SAID ANNULAR CASING SECTION INCLUDING AN INLET AND AN OUTLET IN FLUID FLOW COMMUNICATION WITH SAID INLET AND SAID ROTOR CASING SECTION, A VALVE MEMBER FOR SHUTTING OFF FLOW COMMUNICATION BETWEEN SAID INLET AND SAID OUTLET, AND A RADIALLY EXTENDING SLIDABLE MEMBER FOR OPERATING SAID VALVE MEMBER; A HOLLOW DRUM MOUNTED FOR ROTATION IN SAID ANNULAR CASING SECTION AND HAVING AN ANNULAR INNER WALL; A RADIALLY EXTENDING SHEAR PIN HAVING AN OUTER END ADJACENT THE INNER END OF SAID VALVE OPERATING MEMBER FOR NORMALLY PREVENTING ROTATION OF SAID HOLLOW DRUM; A TURBINE ROTOR IN SAID ROTOR CASING SECTION DRIVEN BY MEDIUM SUPPLIED THROUGH SAID VALVE OUTLET; A SECOND DRUM MOUNTED WITHIN SAID HOLLOW DRUM AND CONNECTED FOR ROTATION WITH SAID ROTOR AND HAVING AN ANNULAR OUTER WALL IN CLOSE PROXIMITY TO SAID INNER WALL WITH SUFFICIENT CLEARANCE THEREBETWEEN FOR FREE ROTARY MOVEMENT OF SAID OUTER WALL WITH RESPECT TO SAID INNER WALL, SAID SECOND DRUM BEING SO CONSTRUCTED AND DIMENSIONED THAT WHEN SAID ROTOR IS DRIVEN AT AN EXCESSIVE SPEED SAID OUTER WALL IS EXPANDED TO CAUSE SAID OUTER WALL TO ENGAGE SAID INNER WALL AND EXERT A FORCE THEREON TENDING TO ROTATE SAID HOLLOW DRUM; AND A CIRCUMFERENTIALLY EXTENDING CAM ON THE OUTER PERIPHERY OF SAID HOLLOW DRUM FOR SHEARING SAID SHEAR PIN AND FOR EFFECTING ACTUATION OF SAID VALVE OPERATING MEMBER BY DISPLACEMENT OF THE OUTER END PORTION OF SAID SHEAR PIN UPON ROTATION OF SAID HOLLOW DRUM TO POSITION SAID VALVE MEMBER TO SHUT OFF THE SUPPLY OF MEDIUM THROUGH SAID VALVE OUTLET AND TO SAID ROTOR.