Patent GB-327108-A (GB)
Title: Improvements in or relating to charge forming devices for internal combustion engines
IPC: F02M19/12
Filed: 1928-09-22
Abstract: 327,108. White, A. E., (Delco-Remy Corporation). Sept. 22, 1928. Spray carburettor.-A charge-forming device comprises a number of primary carburettors, each of which has an individual fuel-metering means, and is adapted to supply a rich mixture to an air passage connected to one of the intake ports of the engine, and all of which are supplied with fuel from a common source through a common metering orifice. The inlet to the air manifold is under the control of a suction-actuated valve, the opening movements of which are resisted by a dashpot. The air manifold 10 has branches 11 - - 13, each of which serves two cylinders. The inlet 17 to the manifold, Fig.< >2, has a fitting 18 with inlet 19 and valve 20, the stem 50 of which is attached to a dashpot piston 52 moving in a cylinder 53 located in the float chamber 30. The lower face of the piston has holes 54 adapted to be closed, on downward movement of the piston, by a disc check-valve 55. A bye-pass connects the upper and lower ends of the cylinder, which is filled with fuel through a port 56. The valve 20 is forced towards its seat by a spring 60 bearing at its upper end against a plate 61 resting against a shoulder on the stem, and at its lower end against a cup 62 adjustable vertically by a yoke 64 mounted on a shaft 65 adapted to be actuated by an external arm from the driving position. A screw stop limits the movement of the yoke. The resistance offered by the dashpot is at first large, but decreases as the piston descends and the bye-pass is uncovered. The air valve is permitted to close rapidly. The casting 36, Fig. 2, has an upstanding part 80 containing two fuel ducts 81, 82 fed from the float chamber through a metering orifice 85, plug 84, and duct 83. The part 80 terminates in a flat top 86 to which is secured by screws a distributing block 90. The flat surtace of this block has two separate fuel channels 93, 94 which register with the ducts 81, 82 and supply fuel to each of three parallel bores 95 - - 97, Fig, 5, through slow-speed orifices 99 and high-speed orifices 98, Figs. 3 and 6. Primary air enters each of the bores through a bush 105 which extends into the bore bevond the orifices so as to prevent the entering air from impinging directly on them. The fuel duct 81, Fig. 2, contains a, gravity valve 88 which is not lifted until the engine speed reaches a predetermined value. The bore 95 registers directly with the manifold branch 12, and the bores 96, 97 are connected respectively to branches 11, 13 through pipes 113. These pipes are connected to fittings 114, Fig. 1, and deliver the rich mixture into a venturi 110. A throttle valve on a spindle 126 in each branch controls the flow of mixture and the throttles are interconnected, so as to be moved together, by rods 128, Fig. 1, and universal flexible couplings 130 - - 135. which permit of slight axial and angular adjustment. The throttles are actuated bv an arm 136, Fig. 1, provided with a slow-running stop. The pressures in the three branches are equalized bv a tube 150 located between each throttle and its corresponding cylinder port.