Patent GB-112418-A (GB)
Title: Improvements in Carburetors for Internal-combustion Engines.
Inventor: BALL FREDERICK OSSIAN
IPC: F02M1/00
Filed: 1917-09-26
Abstract: 112,418. Ball, F. O. Dec. 28, 1916, [Convention date]. Spray carburettors.-Fuel from the float chamber 1, Fig. 2, passes to an anuular space 16 formed between a hollow screw 15 and a cylindrical casing projecting from the carburettor body. From this space, the fuel flows through a passage 18, Fig. 3, a passage 21, and holes 22 in another hollow screw 20, a passage 23 in a third hollow screw 24, holes 28 therein to an annular space 25, Figs. 3 and 4, whence it flows through a passage 29 and annular space 30 formed in the choke tube 31 to a number of nozzles 33. The screw 20 may be replaced by other screws having bores 21 of different diameters to vary the flow of fuel, and the screw 24 is adjustable to vary the height of the holes 28 which are preferably slightly below the normal fuel level. The annular space 25, Fig. 4, is in communication through a by-passage 37 with the mixing chamber 38 above the choke tube 31, the inlet portion 35 of which is more abruptly tapered than the outlet portion 34. When suction occurs, the fuel is atomized not only by air passing through the choke tube, but also by a current of air drawn through the passages 37, 25 into the space 29, 30 where it breaks up the fuel which is delivered through the nozzles in the form of an emulsion or spray. The capacity of the passage 37, 25, 29 is such as to make the mixing chamber pressure communicated therethrough the dominant factor in the control of the fuel. To provide a mixture for slow running, a passage 39 and tuba 40 connect the annular space 30 with a chamber 41 which communicates with the induction pipe on the engine side of the throttle valve 46 through a nozzle 44 having lateral inlet openings 45. A spring-loaded suction-actuated valve 52 admits additional air during the later stages of opening of the throttle valve. To augment the supply of fuel when the throttle valve is opened suddenly, a plunger 59, Figs. 2 and 3, is provided, the stem 62 of which is forced down when the throttle is opened by an arm 75 on the throttle spindle which arm carries a roller 74 which engages a cam surface 73 on a lever 71, a projection 70 on which depresses the spindle 62. The lever 71 is provided with a surface over which the roller 74 may move without moving the lever after the spindle is depressed. The plunger is returned by a spring 61. Forcing down the plunger causes fuel which has passed through a small orifice 58, conduit 64, and orifices 65 to flow, together with air admitted at 69, through a conduit 67 to an additional nozzle 68, Fig. 4. The air inlet 78 is provided with a manually actuated valve 79. In order to obtain a high air velocity at ordinary engine speeds the cross sectional area of the passages of the main carburettor are of such dimensions as to be insufficient to supply the engine at its maximum requirements. To compensate for this, a supplementary carburettor is provided comprising an air inlet 85 inclined to the line of flow through the main carburettor. The inlet has a valve 86 which is opened through a lever and cam mechanism by the throttle valve 46 just before it reaches its fully open position. A choke tube 97 and nozzles 111 also are provided, the nozzles baing fed from the float chamber through a passage 102, hollow screw 105, and annular chamber 100 which is in communication with the mixing chamber through a passage 110, the fuel, as in the case of the main carburettor, being discharged through the nozzles as an emulsion.