Fuel flow control device

A fuel flow control device adapted to replace the conventional pilot jet used on the carburetor of an internal combustion engine, such as an automobile engine, which carburetor comprises a float chamber, a throttle valve interposed between a carbureting chamber and the air-fuel mixture inlet of said engine, a fuel inlet conduit connecting said float chamber to a threaded hole adapted to receive selectively said pilot jet or said control device, and a low pressure conduit connecting said carbureting chamber to said air-fuel mixture inlet, said fuel flow control device comprising a body provided with an externally threaded portion adapted to be screwed into said threaded hole, said body further comprising adjacent to its end thereof, which is adapted to be introduced into said threaded hole, a substantially cylindrical chamber defining a first valve seat at one end thereof into which opens a calibrated passage adapted so as to connect said cylindrical chamber to said fuel inlet conduit, said cylindrical chamber defining at the other end thereof a second valve seat communicating with a laterally disposed passage adapted to be interposed in said low-pressure conduit, a movable valve member being mounted within said cylindrical chamber and adapted to cooperate alternatively with said first and second valve seats, said device further comprising control means adapted to control said valve member so that the latter is disengaged from both said first and second valve seats when said engine operates at idling speed with said throttle valve in the closed position thereof, said valve member engaging said first valve seat when said engine operates at an increased speed after said throttle valve has been moved from the closed position thereof to an open position, and said valve member engaging said second valve seat when said engine operates at a decreasing speed after said throttle valve has been moved from an open position to the closed position thereof.