GB420811A - Improvements in carburettors - Google Patents

Abstract

420,811. Spray carburetters. CARTER CARBURETOR CORPORATION, 2838, North Spring Avenue, St. Louis, Missouri, U.S.A. April 28, 1933, No. 12458. Convention date, May 12, 1932. Addition to 420,810. [Class 7 (iii)] [See also Group XXIX] According to the invention of the parent Specification an eccentrically - mounted choke valve in the air inlet of a carburetter has its initial opening resisted until a predetermined degree of suction is attained, whereupon the valve releases itself and moves freely towards fully-open position. According to the present invention, the initial opening movement is resisted by a drum member yieldablyconnected to the choke valve by a spring and adapted to be engaged by a latch, and means are provided for disengaging the latch when the air choke valve is opened to a predetermined position. One end of a bimetallic coil 30, Fig. 5, is secured to a shaft 31 carried by a housing 32 fixed to the exhaust manifold 12, and the other end 36 engages an adjustable abutment 37 secured by a screw 39 in a slot 38. After the coil has allowed the choke valve to open fully, the end 36 of the coil moves out of engagement with the abutment 37. A lever 42, Fig. 2, on the shaft 31 is connected by a link 44 with an arm 43 rigidly secured to the shaft 8 of the choke valve 7, and a cam 48 mounted on the shaft 8 is connected to the arm 43 by a screw 50 passing through a slot 49. A drum 51 is mounted on the shaft 8 between the cam 48 and the carburetter wall, and is provided with a slot 55 which is engaged, when the engine is stopped and the temperature is low, by a spring-pressed latch 56 mounted on a pin 57. When the engine starts, the suction opens the valve 7 against the resistance of the coil 30 and a spring 52, one end of which is connected to the shaft whilst the other end is engaged in one of a plurality of slots 54 in the periphery of the drum, until the cam 48 passes under the latch 56, and releases the valve. To open the choke valve when the throttle is moved to a wide-open or fully-closed position from a partly-open position, the throttle shaft 24 is provided with a lever which is connected to the lever 43 by a link 63 and a lost-motion device. The throttle valve operates a metering- rod to control the amount of fuel passing to the main nozzle 22 and the slow-running nozzle 25, which discharges at the edge of the throttle valve, and an accelerating-pump which discharges through a separate nozzle into the mixing-chamber.