Abstract: A carburetor for an internal combustion engine has a circuit for delivering a primary air/fuel mixture into the induction passage and means for correcting the richness of the airfuel mixture in dependence of the amplitude of the alternating component of the depression which prevails in operation in the induction passage. The correction device has a movable member which meters an air or fuel flow cross-sectional area in the circuit. The position of the movable member is controlled in dependence of the alternating component by a pressure sensitive diaphragm. A frequency filter connects the induction passage and chambers separated by the diaphragm for dampening the alternating component of the depression by an amount which increases with the frequency of that component.

Abstract: A fuel supply device for internal combustion engines has an injector formed with an injection orifice whose cross-sectional area is adjusted responsive to the position of an auxiliary throttle element located in the intake pipe of the engine and opening automatically and progressively in dependence upon the rate of engine intake air flow. The area is also adjusted as an increasing function of the difference between the pressures upstream and downstream of the auxiliary throttle element.