GB504217A - Improvements in and relating to carburation systems for internal combustion engines - Google Patents

Abstract

504,217. Spray carburetters. SOC. ANON. SOLEX. Feb. 17, 1938, No. 4994. Convention date, July 15, 1937. [Class 7 (iii)] In a carburetter for an engine having means, such as a variable pitch propeller and a centrifugal governor, that can be set to maintain the engine speed constant, a piston 15 or diaphragm, subject through conduits 16, 17 to the differential pressure on opposite sides of a throttle valve 2, is moved by variations in the density of the air upstream of the valve to correct the mixture for changes in altitude. The piston may actuate, directly or through a servo-motor, a fuel valve or a valve for controlling the primary or secondary air. As shown in .Fig. 1, the fuel nozzle 8 is fed from a floatchamber 12 through two calibrated orifices 9, 10 the latter being controlled by a needle valve 11 attached to the piston 15 which operates in a cylinder 14. If the throttlecontrol lever 6 and the lever 23 controling the setting of the constant-speed means remain fixed a reduction in the density of the air drawn in enables a spring 19 to lower the piston 15 to reduce the fuel supply. Movement of either of the levers 6, 23 is transmitted through a lever system to an abutment 26 against which the spring 19 seats, and the lever system is designed so that variations in the differential pressure caused by movement of the levers 6, 23 are balanced by movement of the abutment 26 to vary the tension of the spring 19. The fuel nozzle may discharge into the air stream on the engine side of the throttle and a compressor may be provided on the engine or air inlet side of the throttle valve 2. In the construction shown in Fig. 2, variations in the density of the air open or close the valve 2, and movement of the throttle-control lever 33 or the lever 23 controlling the constant speed of the engine varies the position of the abutment 26 controlling the tension of the spring 19 to regulate the position of the valve 2. The lever 33 also controls a rod 35 to enrich the mixture at large throttle openings.