Patent GB-684099-A (GB)
Title: Liquid fuel control mechanism for internal combustion prime movers
Inventor: IFIELD RICHARD JOSEPH
IPC: F02C7/22
Filed: 1949-11-03
Abstract: 684,099. Gas turbine plant. LUCAS, Ltd., J. Oct. 30 1950 [Nov. 3. 1949], No. 28160/49. Class 110(iii) [Also in Group XXIX] The supply of liquid fuel to a jet engine, gas turbine, or like prime mover is controlled by a throttle 11 actuated by a servo-piston 12 under the control of a manually operated valve 30 which controls the extent of the throttle movement and of a valve 16 which controls the rate of throttle movement and which is operated in one direction by the servo-piston 12 acting through a spring 15 and in the other direction by fluid pressure. The space beneath the piston 12 is supplied from an inlet passage 8 through a restricted orifice 29 and is exhausted through ports 31 controlled by the manually-operated valve 30 and thence through a chamber 17 and a passage 32 leading to a sump or the inlet e of a variable delivery swash-plate pump b supplying the passage 8. A passage 9 conducts fuel to the prime mover. The servo-piston 12 is loaded by two springs 14, 15, the spring 15 also acting through a yoke 27 on the valve 16 which is normally closed under the action of a spring 20 and the pressures acting on two diaphragms 18, 19 of different effective area. The space above the diaphragm 19 is acted on by a pressure related to the speed of the pump b supplied through a passage x. The diaphragms 18, 19 are separated by an annulus 24 and the space between them is exposed to atmospheric pressure through a passage 21. The valve 16 controls a vent passage 25 leading from the space below the piston 12. If the valve 30 is moved so rapidly that the spring 15 actuated by the piston 12 opens the valve 16 before the extra fuel pressure developed by the pump is effective on the diaphragm 19, the vent passage 25 is opened as the ports 31 are closed and the speed of the upward or opening movement of the throttle 11 is limited. The pump b and its control mechanism is of the form described in Specification 577,016, [Group XXIX], the swash-plate d in this case being adjusted by a servo-piston g under the control of a vent valve 5 actuated/ by a diaphragm y subject to a fuel pressure related to the speed of the pump and of a vent valve n controlled jointly by the atmospheric pressure acting on an evacuated capsule u and the pump delivery pressure acting on a plungers. Fig. 2 shows a modification of the manually controlled throttle shown in Fig. 1. In this case, the manually operated control valve 30 is opened to open the throttle 11 and the valve 16 is normally kept open by a tension spring 36 and the fluid pressures on the diaphragms 18, 19 against the tension of a spring 35. The fuel pressure related to the speed of the pump in this case acts below the diaphragm 18. Fuel vented by,the valve 30.passes through a passage in the throttle 11, and through passage 28, 25 to a vent controlled by the valve 16, which in this case closes if the throttle opens too rapidly. The passage 28 is additionally controlled by a normally-open valve 37 itself con trolled by the temperature of the combustion chamber or of the exhaust gases. The valve 37 is closed by a solenoid 38 energized through a thermocouple.