Fuel control device for a gas turbine engine

Claim 1

A FUEL CONTROL DEVICE FOR A GAS TURBINE ENGINE COMPRISING, IN COMBINATION, SPEED SENSING MEANS DRIVEN BY THE ENGINE INCLUDING SPEED OUTPUT MEANS REPRESENTING ACTUAL ENGINE SPEED, SETTABLE MEANS PROVIDING A SPEED REQUEST, CONTROL INPUT MEANS ACTUATED BY THE SETTABLE MEANS PROVIDING AN ACCELERATION REQUEST, ACCELERATION LIMITING MEANS SET BY THE SPEED OUTPUT MEANS AND LIMITING THE SETTING OF THE CONTROL INPUT MEANS IN THE INCREASING DIRECTION AS A FUNCTION OF ENGINE SPEED, ACCELERATION SENSING MEANS DRIVEN BY THE ENGINE INCLUDING ACCELERATION OUTPUT MEANS REPRESENTING ENGINE ACCELERATION, RATE OF CHANGE OF FUEL FLOW CONTROLLING MEANS COUPLED TO THE CONTROL INPUT MEANS AND THE ACCELERATION OUTPUT MEANS AND ADJUSTED FROM A DATUM SETTING IN RESPONSE TO THE DIFFERENCE BETWEEN THE ACCELERATION REQUEST FROM THE CONTROL INPUT AND THE ACCELERATION, AND DISPLACEABLE FUEL METERING MEANS CONTROLLED BY THE RATE OF CHANGE OF FUEL FLOW CONTROLLING MEANS TO INCREASE AND DECREASE FUEL FLOW TO THE ENGINE, THE RATE OF DISPLACEMENT OF THE FUEL METERING MEANS BEING SUBSTANTIALLY PROPORTIONAL TO THE DEPARTURE OF THE RATE OF CHANGE FUEL FLOW CONTROLLING MEANS FROM ITS DATUM SETTING, THE METERING MEANS HAVING AN EXPONENTIAL CHARACTERISTICS OF FUEL FLOW WITH RESPECT TO DISPLACEMENT THEREOF.