GB470646A - Improvements in carburetters for internal combustion engines - Google Patents

Abstract

470,646. Spray carburetters. SOC. GENERALE DES CARBURATEURS ZENITH. Feb. 18, 1936, No. 4960. Convention date, Feb. 19, 1935. [Class 7 (iii)] In a carburetter having a fuel-pressure regulator comprising a diaphragm controlling a fuel inlet valve to the fuel chamber of the regulator, which is floatless, a chamber, separated from the fuel chamber by the diaphragm or having a movable wall operatively connected thereto, is connected by a suction passage to the induction pipe behind the carburetter throttle valve and by an air passage to the air intake or atmosphere and a valve controls one of these passages to increase the suction passage or decrease the air passage in such a ratio that the fuel supply falls below the minimum required to form a combustible mixture. The dry side 14 of a diaphragm 12 is connected by a passage 16, having a calibrated orifice 17, to the atmosphere or air inlet of the carburetter and by a passage 15 with the mixing chamber 1 behind the throttle valve 2, a valve 18 in this passage being adapted to be opened to communicate the depression of the mixing chamber 1 to the chamber 14 and thereby displace the diaphragm 12 to close a fuel inlet valve 11 and stop the engine. Alternatively, the valve 18 may be in the air passage 16 and be closed to stop the engine. In another form, the passages 15, 16 connect with the chamber 14 through a common passage and a two-way valve puts the air channel in communication therewith for normal use or the suction passage when it is desired to stop the engine. As applied to the carburetter described in Specification 464,327, and comprising a manually controlled needle 32, Fig. 5, for varying the amount of suction communicated by a passage 29 from the mixing chamber 1 behind the throttle to the chamber 14 to adjust the strength of the mixture for different altitudes, the chamber 14 communicates through a valve 23 and passage 22 with the air inlet 3 and through a calibrated orifice 36, byepassing the needle valve 32, with the mixing chamber. The orifice 36 and the valve 23 may be interchanged. As shown, the diaphragm 12 is influenced by a spring 13 and the pressure of this may be completely neutralized by associating the diaphragm with a larger diaphragm forming one wall of a chamber corresponding to the chamber 14. In all the above forms, the throttle valve 2 operates a needle valve 5 controlling a spraying orifice 4 arranged above the throttle valve 2. As shown in Fig. 7, the fuel nozzle 41 is below the throttle valve 43 and the chamber 14 is open to the atmosphere through a calibrated orifice 49 and communicates with the induction pipe behind the throttle valve by a valved passage 50. Fuel for idling is supplied through a well 44 and passage 46 having a calibrated air inlet 48. Specification 474,975 also is referred to.