Turbine engine and gearbox mounting arrangement

Claim 1

A SHAFT TURBINE ENGINE AND GEARBOX MOUNTING ARRANGEMENT COMPRISING: (A) A TURBINE ENGINE, (B) A GEARBOX, (C) AN OUTPUT DRIVE SHAFT EXTENDING FEROM SAID TURBINE ENGINE DRIVINGLY CONNECTED TO SAID GEARBOX, (D) A TORQUE TUBE ENCLOSING SAID OUTPUT DRIVE SHAFT AND RIGIDLY INTERCONNECTING SAID TURBINE ENGINE AND SAID GEARBOX, (E) A PROPELLER SHAFT EXTENDING FROM THE GEARBOX, (F) FIRST, SECOND, AND THIRD MEAN MOUNTS ON SAID GEARBOX CIRCUMFERENTIALLY SPACED ABOUT THE GEARBOX PERIPHERY, (G) A FOURTH MAIN MOUNT POSITIONED ON SAID TURBINE ENGINE AND PROVIDING FLEXIBILITY OF MOVEMENT IN THE LONGITUDINAL DIRECTION TO ALLOW FOR THERMAL DEFLECTION IN THE SYSTEM, (H) AND FIRST AND SECOND AUXILIARY MOUNTS ON SAID TURBINE ENGINE, (I) THE SPRING GRADIENT CHARACTERISTIC OF SAID AUXILIARY MOUNTS RELATIVE TO SAID MAIN MOUNTS BEING SUCH AS TO PROVIDE A RELATIVELY SOFT MOUNT CHARACTERISTIC IN THE NORMAL DEFLECTION RANGE AND TO PROVIDE A HARD MOUNT CHARACTERISTIC IN DEFLECTION RNAGES OF A MAGNITUDE REPRESENTING A FAILURE OF ONE OR MORE OF SAID MAIN MOUNTS OR OF SAID TORQUE TUBE, (J) SAID FIRST AND SECOND AUXILIARY MOUNTS BEING SO POSITIONED ON SAID ENGINE SO AS TO BE ABLE TO SUBSTANTIALLY CARRY AN EXCESS LOADING ON THE ENGINE AND GEARBOX DUE TO A FAILURE OF ANY ONE OF THE MAIN MOUNTS OR THE RIGID INTERCONNECTION BETWEEN THE ENGINE AND GEARBOX.