GB159507A - Improvements in and relating to carburetters for internal combustion engines - Google Patents

Abstract

159,507. Pifarre, J. Feb. 26, 1920, [Convention date]. Void [Published under Sect. 91 of the Act]. Spray carburettors.-In a carburettor having means for supplying a limited quantity of mixture for slow-running, means are provided for cutting off this supply entirely when the throttle is closed suddenly, the supply being automatically resumed when the engine speed, and hence the suction above the throttle, falls. In the form shown in Fig. 1, the nozzle 2 is provided with a tube 7 open to the atmosphere and extending as far as the throttle 8. The tube 7 is provided with holes 11 and contains a grooved metal rod 10. During slow-running, fuel is drawn in through the holes 11, and the mixture passes through a passage 9 in the throttle spindle. If, however, the throttle is closed suddenly when the engine is running at full speed, the high suction above the valve lifts the rod 10 and the passage 9 is closed until the suction falls. Air may be admitted to the passage 9 when the valve 8 is closed through ports in the valve spindle controlled by a manually-adjusted needle valve. The wings of the throttle valve are out of alignment to allow the valve to be opened without abutting against the tube 7. The butterfly throttle valve 8 may be replaced by a rotatable plug valve, three forms of which are described, the valve having either a tube or passages corresponding to the passage 9, and a manually adjusted needle valve which allows a controlled admission of air to the passage or to the interior of the throttle valve when closed. In modifications, when the throttle valve is closed suddenly, (1) a ball valve 85, Fig. 7, held in a claw-shaped member 34 in the throttle valve 31, closes the outlet 32a for slow-running mixture; (2) a ball valve mounted in the spindle of a butterfly throttle valve closes a slow-running passage therethrough; (3) a ball valve mounted in the wall of the carburettor closes a mixture inlet therein which opens just above the wing of the throttle valve. In a further modification, the wings of the throttle valve are of unequal size so that a high suction above the valve tends to hold it closed, and a resilient connection is provided in the operating mechanism which allows the valve to open slightly when the suction falls. In the form shown in Fig. 11, the wings of the throttle valve 8<c> are provided with passages the inner ends of which communicate with an outlet passage 47 in the vertical spindle of the valve, and the outer ends, of which. when the valve is closed, register respectively with a fuel supply passage and an air inlet in the carburettor wall. The outlet passage 47 is controlled by a weighted valve 48 which is lifted by suction when the valve is closed suddenly.