Multi-layer anisotropic heat shield construction

Claim 1

AN EXHAUST GAS NOZZLE CONSTRUCTION FOR JET ENGINES HAVING AN EXHAUST GAS DISCHARGE NOZZLE THE INNER SURFACE OF WHICH INCLUDES A THROAT PORTION AND DEFINES A FLOW PASSAGE FOR DISCHARGE OF EXHAUST GASES THROUGH SAID NOZZLE TO PROVIDE THRUST FOR SAID JET ENGINE, SAID EXHAUST GAS NOZZLE CONSTRUCTION COMPRISING AN ANNULAR LOAD CARRYING MEMBER; AN ANNULAR FIRST LAYER FORMING A LINING OVER AT LEAST A PORTION OF THE INNER SURFACE OF SAID LOAD CARRYING MEMBER, SAID FIRST LAYER BEING OF A MATERIAL FOR INSULATING SAID LOAD CARRYING MEMBER AGAINST OUTWARD FLOW INTERNAL HEAT FROM WITHIN THE NOZZLE; AND AN ANNULAR SECOND LAYER DISPOSED OVER AT LEAST A PORTION OF THE INNER SURFACE OF SAID FIRST LAYER, SAID SECOND LAYER BEING OF A MATERIAL WHICH IS ANISOTROPIC IN THAT IT HAS RELATIVELY GOOD HEAT CONDUCTION PROPERTY IN ONE DIRECTION AND HAS RELATIVELY GOOD HEAT INSULATION PROPERTY IN A DIRECTION SUBSTANTIALLY AT RIGHT ANGLES THERETO, THE ANISOTROPIC MATERIAL OF THE SECOND LAYER BEING ORIENTED SO THAT, AT LEAST AT ITS INNER SURFACE, SAID SECOND LAYER HAS RELATIVELY GOOD HEAT CONDUCTION IN A DIRECTION FROM ITS INNER SURFACE TOWARD ITS OUTER SURFACE AND HAS RELATIVELY GOOD HEAT INSULATION IN A DIRECTION AT RIGHT ANGLES TO ITS SAID GOOD HEAT CONDUCTION DIRECTION.