GB410483A - Improvements in carburetors - Google Patents

Abstract

410,483. Spray carburetters. LINGA, T., Kokomo, Indiana, U.S.A. Nov. 10, 1932, No. 31823. [Class 7 (iii).] In a carburetter in which the float chamber is under a suction sufficient to lift the fuel from a low-lying tank, means in the float chamber control the position of an auxiliary air valve. Liquid fuel is drawn by suction from a float chamber 22, Fig. 1, through passages 33, 30, 39 to a closed tube 41, which extends above the level of the fuel in the float chamber, and passes through passages 40, 44 to a fuel nozzle 19 located in a Venturi passage 14, 18. The depression existing in the chamber 40 is transmitted through an orifice 73 to a chamber 72, where it is reduced by a small air-bleed port 74 opening into the mixing chamber 13. An orifice 71 transmits this reduced depression to the top of the float chamber, where it elevates fuel from a supply tank located at a lower level than the carburetter. A flexible diaphragm 25 is clamped between the body and the cover of the float chamber, and carries a nut 53 upon which bears the head 54 of a spring-pressed lever 52, mounted upon a shaft 56 in an eccentric sleeve 57. As the suction in the float chamber increases, the diaphragm flexes against the action of a spring 32, and the lever 52 through links 59, 61, 62 opens an auxiliary air valve 16 to maintain a substantially constant depression in the float chamber. During starting, the valve 16 is held closed by operating a cable attached to an arm mounted on the sleeve 57. A plunger 45 is fixed to the diaphragm 25 and houses an adjustable rod 46 having a hollow part 47 to which is attached a flexible wire 49 carrying a tapered valve 51. The valve 51 is suspended within a calibrated port 37 through which the fuel supplied to the nozzle passes, and as the diaphragm flexes the port 37 is opened. The fuel supply for idling is adjusted by altering the position of the valve 51 by means of the adjustable rod 46. At high speeds the richness of the mixture is controlled by a manually adjustable valve 43. When accelerating, (1) the diaphragm will move downwardly and, as the air beneath it cannot escape quickly through the small orifice 71, the pressure in the float chamber increases and fuel will be forced out of the float chamber through passages 77, 76, 75, Fig. 3, into the chamber 72, from which it passes through the opening 73 into the main fuel passage 40, 44 ; and (2), due to the retardation of the downward movement of the diaphragm 25, the opening of the auxiliary air valve 16 is delayed. During the last eighth of the opening movement of the throttle valve 15, a slot 85 in its shaft registers with a passage 82 leading to the chamber 72 through passages 81, 79, 78, and thus the difference in depression between the port 37 and the top of the float chamber is increased, and extra fuel is supplied through the port 37. The space above the diaphragm in the float chamber is connected with the conduit 17.