Patent GB-600815-A (GB)
Title: Improvements in and relating to combustible charge supply systems
IPC: F02D9/00
Filed: 1944-10-03
Abstract: 600,815. Charge-forming devices. LEIBING, W. E., and FAGEOL, R. DE E. Oct. 3, 1944, Nos. 18904, 18905 and 18907. Convention dates, Nov. 10, 1943, Feb. 28, 1944, and May 3, 1944. [A Specification was laid open to inspection under Sect. 91 of the Acts, Dec. 8, 1944.] [Class 7 (iii)] A charge-forming device comprises means for supplying fuel from a reservoir to an induction passage at substantially constant pressure, a vane located in and responsive to air flow in the induction passage, the vane operating a valve which controls the flow of fuel to the induction passage, a throttle valve controlling the flow of air in the induction passage independently of the vane and means for returning fuel vapour and excess fuel to the reservoir. As shown, fuel under pressure supplied to a nozzle 100 is controlled by a valve 93 operated by the movement of a spring-loaded air vane 30. The movement of the vane is transmitted to the valve by means of a cam 76 attached to the vane and operating through a lever 80. A device for enriching the mixture at idling (not shown) comprises a diaphragm operated by suction on the engine side of a manuallyoperated throttle 24. Movement of the diaphragm is transmitted by levers to a pin 82 eccentrically fixed on a spindle (not shown). The valve lever 80 is mounted on the pin. Motion of the pin varies the mixture by varying the opening of the fuel valve. A suctionoperated piston varies the tension of the spiral spring 40 of the air vane and weakens the mixture at idling and enriches it when the throttle valve is suddenly opened. It is stated that the effect of the diaphragm overrides the effect of the piston so that a rich mixture is-produced at idling. As soon as the throttle valve is opened sufficiently, however, the pin 82 is restored to normal operation and a lean mixture is produced by the action of the piston. A bimetallic thermostatic spiral strip decreases the tension of the air vane spring when the carburetter is cold and so facilitates starting by enriching the mixture. The manually-operated throttle valve 24 has a spring strip 144 thereon which passes air when starting so that it is not necessary to open the throttle valve. As soon as the engine commences to run, the increase in suction draws the strip towards the throttle valve and decreases the mixture strength to that required to maintain idling of the engine. If the engine slows down, the drop in suction allows the spring to open and increase the idling mixture strength. The air vane is curved at one side and is cut away at the other side adjacent the fuel nozzle. The air rushing through the cutaway portion helps to atomise the fuel. The curved portion delays the opening of the passage by the air vane. The fuel system has a separating chamber and at the upper portion of this a passage for excess fuel to flow back to the fuel tank to eliminate vapour locks. A fuel filter is located in the separating chamber at the outlet. An inertia member 62, acting as a brake against sudden movement of the vane, is connected to the shaft of the vane by friction between the member and a disc 67 on the shaft, a spring 63 pressing the member against the disc.