High velocity carburetor

Claim 1

A multibarrel, multistage carburetor for a spark ignition internal combustion engine which comprises a. at least one primary barrel which includes 1. a first mixing conduit having a venturi, 2. a fuel nozzle situated in said venturi to deliver fuel to said first conduit, 3. a first throttle means mounted in said conduit downstream of said fuel nozzle, said throttle means being manually moveable between opened and closed position, 4. choke means situated in said first conduit upstream of said nozzle, said choke means being mounted in said conduit to permit manual movement between closed and opened positions, 5. a vacuum modulated throttle by-pass which provides required enrichment of fuel/air mixture during engine deceleration, and b. at least one secondary barrel, having no choke means, which includes 6. a second mixing conduit having a cross-sectional area larger than said first mixing conduit, 7. a second throttle means rotatably mounted in said second conduit to permit manual movement between closed and opened positions, said second throttle means being directly linked to said first throttle means so that said second throttle means begins to open when said first throttle means reaches a predetermined open position, 8. slidably adjustable means situated above said second throttle means, and being positioned to move across the short axis of and into said second conduit, said slidably adjustable means having a needle axially attached to the end which enters said conduit and being attached to a vacuum operator at the opposite end, said vacuum operator being responsive to a vacuum signal obtained at a point in said second conduit just above said second throttle means, 9. a fuel orifice for providing fuel to said second conduit, situated in said second conduit upstream of said second throttle means and opposite said slidably adjustable means, the extent of said fuel orifice opening being controlled by the movement of said needle into and out of said orifice as said slidably adjustable means responds to said vacuum operator, 10. a fuel/air mixture enrichment means which comprises a vane situated in and substantially parallel to the long axis of said second conduit, said vane being responsive to manifold vacuum and acting to reduce the cross-section area of said second conduit in the region of the slidably adjustable means at high engine loads, said primary barrel providing fuel/air mixture to said engine at idle and relatively low engine loads and combining with said second barrel to provide fuel/air mixture to said engine at higher engine load.