Devices for the metered supply of liquid fuel to combustion engines, more particularly to aircraft gas-turbine engines

Apparatus for supplying a controlled amount of fuel to a gas-turbine engine of an aircraft, said gas-turbine engine having a compressor, said apparatus comprising in combination:

• 1. a fuel tank for containing fuel for said engine;
• 2. a pump for delivering said fuel under pressure to said engine;
• 3. throttle means for enabling a pilot of said aircraft to adjust the flow of said fuel passing through said throttle means and destined for said engine;
• 4. a plurality of nozzles which are electrically energisable with such a mark/space ratio of energisation that they inject fuel into said engine in a rapid sequence of short uniformly time-spaced pulses;
• 5. electronic controller means for controlling said mark/space ratio of energisation of said nozzles by varying the ratio of the length of said pulses in relation to the length of the intervals between said pulses;
• and
• 6. fuel flow control means responsive to the difference in pressure between the fuel pressure at said throttle means and delivery pressure of said compressor, said flow control means being operative to maintain this pressure difference constant whereby the rate of said fuel delivery to said engine at any given setting of said throttle means is dependent only upon said mark space ratio set by said electronic controller means.