US 4,447,371 A · Carburetor

Abstract

A side draft carburetor is disclosed in which an eccentrically mounted throttle plate is provided with an aperture for passage of air therethrough and for movement of the throttle plate over a nozzle block interferingly projecting into the main air passageway of the carburetor. The nozzle block is equipped with a nozzle for introducing fuel into a venturi passageway formed between the nozzle block and a cam surface located about the rotational axis of the throttle plate; the cam surface moving with the throttle plate to vary the size and shape of the venturi passageway at the point of fuel introduction. This produces a finely atomized fuel mixture substantially centrally of the main air stream for optimum diffusion of the incoming fuel. In a modified version, the variable venturi passageway is effected by a flexible leaf spring responsive to a cam surface movable with the throttle plate to produce a passageway varying between convergent and divergent form as the throttle plate moves between closed and open positions. In both embodiments, the variable venturi passageway is restricted to a finite cross section of the carburetor's main intake air passageway defined by the effective aperture through the throttle plate, the nozzle block, the cam surface and laterally spaced barriers between the cam and the nozzle block.

Claims9

Dependent claims

A carburetor for internal combustion engines, comprising a main body having intake air passageway means of generally circular cross-section communication between atmospheric air and the intake manifold of the engine, a single planar throttle plate configured to fit the cross-section of said passageway means and mounted for limited rotational movement about an axis transverse of said passageway means to operably control the flow of air therethrough;

a nozzle block extending into said passageway means in interfering relation with the rotational path of said throttle plate and having fuel introducing means at an outer end face thereof for introducing fuel substantially centrally into the stream of air flowing through said passageway means;
said throttle plate having a cut away area extending inwardly of its periphery for registering reception of said nozzle block whereby to afford movement of said throttle plate over said block;
and means cooperating with said nozzle block and moveable coaxially with said throttle plate and toward and away from said outer end face of said block to effectuate a variable size, convergent/divergent venturi passageway therebetween;
said venturi passageway having its zone of maximum air velocity generally opposite the point of fuel introduction from said fuel introducing means with the vacuum effect of said venturi passageway being isolated from and independent of the engine's manifold vacuum and varying directly with the positioning of said throttle plate across said passageway means throughout said plate's range of movement.

1 more element

Dependencies are inferred from the claim text.

Carburetor

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Carburetor

Life of this patent

Abstract

Claims9