GB401742A - Improvements in or relating to carburettors for internal combustion engines - Google Patents

Abstract

401,742. Spray carburetters. NUGENT, P. R., Lad Lane, Dublin. May 20, 1932, No. 14382. [Class 7 (iii).] In a carburetter having main and pilot nozzles both of which slide into bores in the carburetter casing, the nozzle members are of different diameters to ensure that neither will fit into the bore of the other. Bores 4, Fig. 1, of dissimilar size, are formed side by side in the web 3 connecting the float chamber 1 with the induction tube 2, and jets or nozzle members 7, 20 are made sliding fits therein. Fuel, normally at a level L in the float chamber 1 flows through an outlet 6 to the bore 4 for the main nozzle member 7, which is of dumbbell shape, and through a recess in the lower portion 8 thereof to an orifice 12 in the waist portion. Here it mixes, in the bore 4, with ai'r drawn through orifices 13 from a recess in the upper end 7<1> of the nozzle member and the mixture is sucked through a passage 9 and slot 18 into the induction tube 2 by air drawn through the throat of the tube. At starting or during idling, the fuel leaves the chamber 1 by an outlet 21 at a higher level than the outlet 6 and flows through an orifice 23, Fig. 5, in the waist portion of the pilot nozzle 20 to a duct 24 therein which communicates with the atmosphere by an orifice controlled by a screw 25. Fuel flows to a reservoir passage 26 from which it is drawn through a siphon-like duct to an inlet so disposed in the induction tube as to be covered, by a projection 29 on the throttle 16 when the throttle is closed but to be uncovered on slight opening thereof at which position, the suction in the throat of the induction tube is insufficient to induce a flow of fuel through the main nozzle 7. A small drain duct is provided in the induction tube adjacent the throttle valve 16. Specification 157,528, [Class 7 (iii), Internal-combustion engines, Carburetting-apparatus &c. for], is referred to.