Air-fuel mixture enriching device for constant vacuum type carburetors

Claim 1

An air-fuel mixture enriching device for a constant vacuum type carburetor, comprising wall means forming an axially extending induction passage having a suction end and an oppositely disposed engine manifold end and containing a venturi intermediate its ends, a throttle valve located within said induction passage between the venturi and the engine manifold end, a vacuum piston extending into said induction passage intermediate its ends and transversely of its axis and being located opposite said venturi, a float chamber located exteriorly of said induction passage, a first sump located within said float chamber, a main fuel nozzle opening into said induction passage at said venturi and arranged in communication with said float chamber through the medium of said first sump, a separate airfuel enriching device fixed to and extending below the lower end of said float chamber, a chamber in said air-fuel enriching device, a passageway connecting said chamber and said float chamber, an enrichment jet located within said passage intermediate said float chamber and said chamber, a second fuel sump located within said device, a second passageway interconnecting said chamber and said second fuel sump, said chamber having a valve seat therein at the opening to said second passageway, a valve located within said second passageway and having a first part located within said chamber which part is displaceably engageable with the valve seat therein and a second part extending through said second passageway into said fuel sump, a secondary fuel outlet passage formed separately and independently of said main fuel nozzle and connected at one end to the upper portion of said fuel sump and at its other end into said induction passage between said main fuel nozzle and said throttle valve, a second chamber within said enriching device located below said second fuel sump, a diaphragm disposed within said enriching device and forming a separating partition between said second chamber and said second fuel sump, a second part of said valve being secured to said diaphragm, spring means associated with said valve for resiliently biasing said valve, and means associated with said second chamber for opening said valve and effecting a flow of secondary fuel into said second sump and then from said second sump into said secondary fuel outlet passage for supplying the secondary fuel into said induction passage when the engine to which the carburetor is attached is operated at higher speeds.