GB434292A - Improvements in or relating to carbureters - Google Patents

Abstract

434,292. Spray carburetters. STEVENS, A. H., 5, Quality Court, Chancery Lane, London.-(Marvel Carburetter Co. ; 1910, St. John's Street, Flint, Michigan, U.S.A.) May 26, 1934, No. 15759. [Class 7 (iii)] Consists in a downdraught carburetter having a butterfly throttle valve with the fuel nozzle located in the air inlet side of the wing which moves downwardly on opening. The carburetter comprises a casing 12, a choke tube 17, an air choke 22 and a throttle 19, in the downwardly movable wing of which is formed the nozzle 35 which communicates with the fuel in the float chamber 15 through a duct 36 in the throttle spindle, a calibrated port 50, valve 59, and ducts 46, 45 m a member 40 which is secured to the throttle spindle to swing therewith. The member 40 forms a cylinder for a spring-loaded piston 44 of an accelerating pump, the piston being actuated, as the throttle is opened, by a cam member 51 forcing upwardly a stem 42 on the piston. During upward movement of the piston, a disc valve 58 closes ports 46, and a reduced part 59<1> of valve 59 serves to allow of the passage of an increased quantity of fuel. Instead of a two-diameter type of valve, a tapered form may be employed. For idling purposes, fuel is supplied to a controlled outlet 76, Fig. 4, from a well 15 through tube 64, orifice 66, and duct 68, and air is admitted through a duct 73 and orifice 72. In a modification, Fig. 5, the port 50 is retained and the fuel supply thereto is metered by an orifice 81 until the throttle is opened to such an extent that the cam 51 opens a seated valve 86. Air is admitted to the fuel stream through apertures 89, 88<1>, 88<11>, and a ball valve 89<1> prevents escape of fuel when the accelerating pump is in action. In a further modification, Fig. 6 (not shown), the accelerating pump is dispensed with and the fuel is controlled by a valve in the lower end of the swinging member by the cam 51, air being again admitted to the fuel. In a still further modification, Fig. 8 (not shown), the swinging member comprises two pipe branches, the free ends having calibrated inlets. One inlet is always submerged, the other being submerged as the throttle is opened. In a modification of the idling device, fuel is discharged through apertures in the throttle and its shaft, Fig. 7 (not shown).