Variable throat venturi apparatus for mixing and modulating liquid fuel and intake air to an internal combustion engine

In a liquid fuel and intake air mixing and modulating device for supplying a combustion mixture to an internal combustion engine as a high velocity air stream incurring sonic velocity over most of the operating range of the engine to which it is supplied by efficient kinetic energy conversion of the air stream to static pressure and including a housing;

• oppositely positioned members within said housing, said members comprising walls supported in angularly fixed relation to each other and defining a venturi flow passage intervening therebetween;
• fuel intake means to receive quantities of liquid fuel to be introduced in a substantially uniform pattern into said passage;
• and adjustment means operative to vary the flow area of said passage in correlation to operating demands imposed upon the engine without changing the angular relation between the passage defining walls of said members, the improvement comprising control means for adjustably varying the area ratio between the exit plane of said passage and the throat plane of said passage to within a predetermined range from a ratio at wide open throttle operation of the engine of about 1.3:1 by effecting an idle operation passage area aspect ratio measured at said throat plane different than the aspect ratio defined by the throat plane area over the longitudinal extent of said members.

In a liquid fuel and intake air mixing and modulating device for supplying a combustion mixture to an internal combustion engine as a high velocity air stream incurring sonic velocity over most of the operating range of the engine to which it is supplied by efficient kinetic energy conversion of the air stream to static pressure and including a housing;

• oppositely positioned members within said housing defining by their walls a venturi flow passage intervening therebetween;
• fuel intake means to receive quantities of liquid fuel to be introduced in a substantially uniform pattern into said passage;
• and adjustment means operative to vary the flow area of said passage in correlation to operating demands imposed upon the engine, the improvement comprising at least one of said members including a diffuser gate pivotally supported therefrom for defining the diffuser portion thereof and control means for adjustably varying the area ratio between the exit plane of said passage and the throat plane of said passage to within a predetermined range from a ratio at wide open throttle operation of the engine of about 1.3:1 by reducing the divergence angle of said gate concomitantly with adjustment means variation of said passage toward idle operation.