GB560010A - Improvements in or relating to carburetters for internal combustion engines - Google Patents

Abstract

560,010. Spray carburetters. BENDIX AVIATION CORPORATION. Sept. 11, 1942, No. 12869. Convention date, April 2, 1942. Addition to 549,576. [Class 7 (iii)] In a carburetter according to the parent Specification, having the spring-closed valve 296 for closing the air bleed to the idling system actuated by a piston 274 responsive to suction posterior to the throttle valve 226, the piston 274 also actuates an economizer valve 264 adapted to enrich the fuel mixture when the engine is working under heavy load, the valve 264 being opened when the piston 274 is in " bleed closed " position. In the downdraught carburetter shown, the piston 274 moves in a cylinder connected by ducts 278, 280, 282, 284 to the mixture passage 224 beyond the throttle, and a recess 296 around the piston is adapted to connect passages 286, 287, so that air is bled to the idling system from the air inlet 218 through passages 286, 287, 288 and a restricted orifice 290. A spring 270 around the stem 268 of the piston 274 tends to hold the piston in " bleed closed " position, the stem then opening the economizer valve 264- to admit extra fuel from the float chamber 234 to the fuel well 244. An air bleed passage 300, permanently open, prevents fuel from siphoning into the #-shaped passage 248, 250, 252 conveying the idling fuel from the well 244 to the idling jets 254, 256. Air is bled to the main fuel nozzle 238 from a passage 242 connected to the well 244, with which the nozzle 238 communicates through openings 246. The invention is applicable to updraught carburetters and to carburetters of multiple-barrel construction or having independent main and idling fuel systems.