GB233580A - Improvements in or relating to carburettors for internal combustion engines - Google Patents

Abstract

233,580. Stromberg Motor Devices Co., and Mock, F. C. Jan. 31, 1924. Spray carburettors. - In a carburettor, particularly for use on aircraft, wherein the float-feed apparatus surrounds the mixing chamber or chambers, the floats and their actuating-mechanism are so designed that the fuel level is maintained constant during a predetermined degree of fore-and-aft tilting, but is raised by a further inflow of fuel upon said degree of tilting being exceeded. The carburettor comprises a casing consisting of a lower part 23 .and an upper 24 joining along the line 25 which is above the normal fuel level x-x. Extending upwardly through the casing are two carburettor barrels 27, each having a Venturi tube 28, a main nozzle 29 and a butterfly throttle valve. The float chamber substantially surrounds the barrels 27 and comprises front and rear areas 34, 35 of about the same capacity connected by a tube 36 along the fore-and-aft, axis of the carburettor. This tube quickly conveys fuel from one area to the other when tilting occurs. Two drum-shaped, floats 37 of equal size are located in the areas 34, 35 and are attached to arms 38 of a yoke 39 over a pin 43 in which the fuel valve 42 is hooked. The yoke is pivoted on pins 44. The valve 42 is guided in a tubular plug 45 and engages a hard metal seat 46 at the lower end of the plug. Fuel enters at 57 a chamber 54 containing a gauze strainer and leaves by way of a tube 58 to pass along a conduit 47 to the valve seat 46. The normal fuel level x-x is slightly above the centres of the floats 37 to ensure an ample supply of fuel. The floats are so designed that the force required to close the valve 42 is approximately fourteen-twelfths of the force exerted through its arm 38 by one float when fully submerged. If the degree of tilting is such that both floats are in the fuel, the decreased buoyancy of one float is made up by the increased buoyancy of the other, and the valve remains closed. When, however, this degree is exceeded and one float is wholly out of the fuel, the other float, although completely submerged, is incapable of holding the valve closed. Fuel therefore enters the chamber and the level is raised. The floats are braced internally by tubular struts 60. Fuel is supplied to the nozzles through ducts 61 opening into the chamber close to the medium plane. An arrangement of two of the carburettors in a typical V type aeronautical engine is described and shown in the Specification.