GB403797A - Improvements relating to carburettors for internal combustion engines - Google Patents

Abstract

403,797. Spray carburetters. SOC. ANON. SOLEX, 190, Avenue de Neuilly, Neuilly-sur-Seine, France. Nov. 24, 1932, No. 33252. Convention date, Jan. 21. [Class 7 (iii).] The maximum engine speed is limited to a predetermined value by using the suctions existing in front of and beyond the throttle valve in combination to stop the feed of fuel to the nozzle when these combined suctions exceed that corresponding to the maximum engine speed. The ratio of the suctions may be arranged so that the magnitude of the combined suctions is independent of the position of the throttle to produce a single maximum speed, or so that the magnitude of the combined suctions is dependent on the throttle position to produce various maximum speeds. As shown in Fig. 1, the suction is transmitted to the float chamber 1 through orifices 5, 6, a chamber 3, and a passage 2, and causes the fuel level in a well 12 beyond the nozzle to fall. As the maximum speed is approached, air enters through the well 12 and a calibrated orifice 11 to stop the fuel flow to the nozzle 10. The chamber 2 communicates with the atmosphere through a calibrated orifice 7‹. To suppress the suction during slow running, either (1) the orifice 5 enters the mixing conduit 1a at a point which is a little in front of the throttle valve 4 when closed, (2) the throttle valve carries an extension to close the passage between the orifice 5 and the float chamber 1 when the valve is closed, or (3) the chamber 3 is put into communication with the atmosphere by apertures 8 which open into a recess 9 in the axis of the valve 4 when it is nearly closed. In a modified construction, the fuel flow to the nozzle is interrupted by a closure member attached to a piston which is exposed on one side to the suctions beyond and in front of the throttle, and on the other side to atmospheric pressure.