Patent GB-804529-A (GB)
Title: Improvements in or relating to carburettors
Inventor: HEADLAND EDWARD JOHN
IPC: F02M3/08
Filed: 1956-05-18
Abstract: 804,529. Carburetters. HEADLAND CARBURETTERS, Ltd. May 20, 1957 [May 18, 1956], No. 15581/56. Class 7(3) A carburetter comprises main jet 4a and pilot jet 4b assemblages disposed in spaced bores which are vertical or substantially vertical and connected by a fuel duct 4d at a lower part and at an upper part by a transverse channel 4e normally below fuel level and communicating between a pilot jet well and a space between the main jet 7 and an emulsion jet 8 which is disposed above the main jet and projects into the intake passage of the carburetter, the well having an air inlet bleed 11 at the top and an air bleed connection 9a to the pilot jet at the bottom of the well being provided a fuel inlet connection to the fuel duct, a master jet 10 disposed between the fuel inlet and the lower end of the pilot jet and a controllable air inlet 6b to a mixing chamber 6e above the pilot jet the mixing chamber communicating through a slow running adjustment device 5 with a pilot inlet 5d to the intake passage in the region of the throttle member the sizes of the jets and bleed passages being so correlated that as the throttle is opened primary air supplied first to the pilot jet is distributed next to the space between the main and emulsion jets and thereafter through the master jet to the main jet for progressively weakening the mixture For starting from cold, the needle 6a of the controllable air inlet device is closed. The carburetter is not flooded. When the engine is started the air inlet device 6 is opened so that the engine runs smoothly. At this stage, mixture is conducted through the passage 12 to the slow running adjustment device 5 and from thence through the passage 5d to the intake passage, additional air being admitted through the passage 5e. As the throttle slide is opened further suction on the pilot jet 9 decreases and the emulsion jet 8 comes into operation to pass fuel into the main air stream. At this stage the emulsion jet 8 is fed with fuel via the passage 4e communicating with the pilot jet well in the bore 4b and through the master jet 10. On the throttle slide being opened further the main jet 7 comes into action, the fuel level in the pilot jet 9 and the pilot jet well falls below the normal fuel level and air entering the well through the air bleed inlet 11a passes through the channel 4e to the space 7e between the main jet 7 and the emulsion jet 8 so as to mix with fuel emerging from the main jet 7 and weakening the mixture when it is tending to become too rich. When the throttle slide is opened further all fuel is drained from the pilot jet well and air entering through the empty pilot jet 9 from the device 6 and also through the bleed inlet 11a flows in addition through the bleed holes 10b in the master jet 10 so as to enter the main fuel supply duct 4d for adjusting the fuel-air ratio passing through the main jet 7 to meet varying conditions. The throttle slide may be arranged at any suitable angle in relation to the intake passage or may be replaced by a throttle control of the usual butterfly type.