GB292174A - Improvements in or relating to carburetters - Google Patents

Abstract

292,174. Soc. du Carburateur Zenith. June 17, 1927, [Convention date]. Spray carburettors.-In carburettors provided with two or more co-axial Venturi tubes the passages through which are invariable, the depression is controlled by a suction-actuated eccentrically-pivoted balanced valve 5 situated in the air intake 4, a conduit 23 of relatively small crosssection, which either passes through the valve 5 or through the wall of the intake 4 and leads to the inner Venturi tube 32, admitting an uncontrolled supply of air adjacent the outlet of the rich mixture admission conduit 2. The valve 5 is mounted on conical frictionless pivots 7, 8, is loaded by a spring 16 or by a weight, and its movements are damped by a dashpot comprising a cylinder 20 and a piston 19 connected by an arm 11 to the spindle 6 of the valve. To ensure a constant rate of filling of the engine cylinder, the loading of the valve 5 is considerable, so that the valve only opens for a relatively strong suction, the resistance to the opening of the valve being diminished as the engine speed increases by suction transmitted from the Venturi 32 through a conduit 28 to a piston 25 connected to the valve spindle. In a modification, the piston 25 and conduit 28 are dispensed with, in which case the valve is more lightly loaded. To prevent excessive fuel flow at low speeds, the float chamber 30 communicates with the mixing-chamber through an aperture 29.