Fuel control for a gas turbine engine

Claim 1

A GAS TURBINE ENGINE FUEL SYSTEM FOR CONTROLLING THE SUPPLY OF PRESSURIZED FUEL FROM A SOURCE THEREOF TO A BURNER OF A GAS TURBINE ENGINE COMPRISING A CYLINDRICAL METERING DEVICE, SAID DEVICE COMPRISING A PAIR OF APERTURED CYLINDRICAL MEMBERS AXIALLY MOUNTED THE ONE WITHIN THE OTHER FOR RELATIVE AXIAL MOVEMENT, THE OUTER CYLINDRICAL MEMBER HAVING TWO AXIALLY ALIGNED SPACED PARTS WHICH ARE RELATIVELY MOVABLE IN AN AXIAL DIRECTION TO VARY THE SPACE BETWEEN THE TWO RESPECTIVE PARTS, THUS FORMING THE APERTURE IN THE OUTER CYLINDRICAL MEMBER, A METERING ORIFICE FORMED BY THE CYLINDRICAL MEMBER, A METERING CYLINDRICAL MEMBERS, MEANS FOR VARYING THE SIZE OF THE METERING ORIFICE IN ACCORDANCE WITH ENGINE ROTATIONAL SPEED, SAID MEANS COMPRISING A CENTRIGUFAL GOVERNOR CONNECTED TO A MOVABLE CYLINDRICAL PART OF THE OUTER CYLINDRICAL MEMEBR AND ACTUATED BY THE ENGINE ROTATIONAL SPEED TO VARY THE SPACE BETWEEN THE TWO RELATIVELY MOVABLE PARTS AND THE APERTURE FORMED THEREBY, MEANS RESPONSIVE TO THE ENGINE THROTTLE SETTING TO VARY THE SPEED AT WHICH THE CENTRIFUGAL GOVERNOR MOVES THE MOVABLE CYLINDRICAL PART OF THE OUTER CYLINDRICAL MEMBBER, SAID MEANS RESPONSIVE TO THE ENGINE THROTTLE SETTING INCLUDING A SPRING DRIVE MEANS AND A TEMPERATURE COMPENSATING MEMBER SENSITIVE TO FUEL TEMPERATURE TO VARY THE EFFECT OF SAID DRIVE MEANS IN ORDER TO COMPENSATE FOR MECHANICAL CHANGES IN THE SAID ENGINE THROTTLE SETTING RESPONSIVE MEANS DEVELOPED BY FUEL TEMPERATURE CHANGE; MEANS FOR VARYING THE METERING ORFICE IN FUNCTIONAL RELATIONSHIP WITH THE OUTLET AND INTAKE PRESSRUES OF THE COMPRESSOR MEANS OF THE ENGINE, A THROTTLE VALVE FOR CONTROLLING THE FUEL FLOW IN ACCORDANCE WITH THE FUEL PRESSURE DROP ACROSS THE METERING ORIFICE AND IN RESPONSE TO ROTATIONAL SPEED OF THE ENGINE, A SECOND CENTRIFUGAL GOVERNOR CONNECTED TO SAID THROTTLE VALVE AND ACTIVATED BY THE ENGINE ROTATIONAL SPEED TO VARY THE POSITION OF THE THROTTLE VALVE, THE THROTTLE VALVE BEING SLIDABLY MOUNTED WITH THE INNER APERTURED MEMBER OF THE CYLINDRICAL METERING DEVICE, SAID VALVE HAVING A PISTON PORTION HAVING OPPOSITELY DISPOSED PRESSURE FACES RESPECTIVELY OPEN TO THE PRESSURES IMMEDIATELY UPSTREAM AND DOWNSTREAM OF THE METERING ORIFICE, AND MEANS PROVIDING RELATIVE ROTATION BETWEEN THE THROTTLE VALVE, THE INNER AND OUTER CYLINDRICAL MEMBERS OF THE CYLINDRICAL METERING DEVICE.