GB392968A - Improvements in carburetors - Google Patents

Abstract

392,968. Spray carburetters ; pumps. BENDIX AVIATION CORPORATION, 105, West Adams Street, Chicago, U.S.A. Nov. 28, 1931, No. 33049. Convention date, Dec. 4, 1930. [Classes 7 (ii) and 7 (iii).] In a combined carburetter and impeller, a primary mixture formed at a point where the air acquires a high speed, is enriched as it passes through the impeller which distributes it to the engine manifold. Fuel is drawn from a float chamber 1, via a metering orifice 3a, to an annular chamber 4 which communicates with nozzles 27 and a nozzle 22 of a sleeve 21 controlled by a needle valve 20. The air is whirled on entry by a spiral-shaped chamber 11 and tangential tapering vanes 15 ; the mixture is controlled by a sliding annular valve 16 operated by a lever 35, a push rod 36 ensuring that the valves 16, 20 are closed simultaneously; the connecting lever 39 is, however, flexible so that the fuel valve 20 can be opened at starting by the hand control 42 of the surrounding sleeve 21. Fuel is drawn from a chamber 55 in the impeller wheel through passages 54 which terminate round the hub as shown, or at the blade tips, there enriching the main .charge which is distributed to the combustion chambers by passages 10. In a modification, Fig. 5, the air enters through a Venturi tube 63 having fuel orifices 64 supplied from a float chamber 67 through a nozzle 66 ; the enriching fuel passes through a constriction 73, surrounded by an adjustable baffle 74, up a tube 71, and past a throttle valve 85, adjusted by a lever 86 having an adjustable stop 88. The main throttle valve 61 is linked to a spring- pressed diaphragm 101, the lower side of which is kept at atmospheric pressure, while the other side is connected to the induction passage by bores 111, 109, and to the atmosphere, by a passage 110, controlled by a valve 114, lifted by a cam 95 ; when the cam is rotated to close the valve, an arm 92 of the operating lever strikes the lever 86 and the mechanism ensures that the tube 71 is supplied with fuel while suction is building up, above the diaphragm, to open the valve 61. As modified in Fig. 6, a throttle valve 126 is operated by a plunger 127 according to the difference in pressure on the two sides of a diaphragm connected to points 132, 135 below and above the Venturi tube 63.