Abstract: A fuel supply system supplies volatile fuel at a controlled rate to an air-fuel mixing chamber leading to a subatmospheric intake manifold of an internal combustion engine. Fuel is metered out by a metering gear pump supplied with fuel under pressure sufficient to maintain the fuel in its liquid state. An equalizer valve maintains the pressures on the two sides of the gear pump equal. This assures linearity of fuel rate as a function of pump speed. Pump speed is measured to provide a feedback signal to a controller. The controller compares the feedback with a control signal indicative of desired rate of fuel to develop driving power for application to the gear pump to drive the latter at the speed that supplies fuel at the desired rate.

Abstract: An auxiliary air control system controls the flow of air into the intake manifold of an internal combustion engine. The system controls flow through a valve bypassing the main throttle valve to maintain an appropriate rate of air flow. A manifold pressure signal is fed back to a control circuit for comparison with a manifold pressure reference and development of a manifold pressure control signal for positioning the bypass valve to admit air at a rate maintaining the manifold pressure at the reference pressure and thus avoid low manifold pressures as cause excessive emissions of pollutants. A signal indicative of rate of air flow is fed back to the controller for comparison with an air flow reference and development of an air flow control signal for positioning the bypass valve to admit air at a rate maintaining total air flow at the reference rate, as for engine idle. The control signals are applied to admit air at the greater of the two rates.

Abstract: An air flow transducer for measuring rate of air flow into an engine having a propensity to backfire includes a rotor with vanes disposed to intercept the air flow. The vanes are formed of low density plastic and affixed to a rotor. The trailing edges of the vanes are shaped to direct forces occasioned by backfire pressure waves to hold the vanes to the hub.

Abstract: A carburetor for an internal combustion engine having an intake manifold includes a hollow air control valve, preferably conical, formed by outer and inner hollow valve members having mating surfaces of revolution about an axis. The inner valve member confines a coaxial internal mixing chamber having a cross section increasing in the direction away from the mating surfaces and terminating in an open end extending toward the intake manifold. The valve members are mounted to intercept air inflow into the intake manifold with the valve members being turnable relative to each other about the axis to change the overlap of respective openings and thereby vary the constriction of air flow at the overlaps to control the rate of air flow into the intake manifold. The respective openings are relatively disposed to direct air flow through each overlap with a transverse component of air flow offset from the direction toward the axis, thereby causing a swirling of air within the mixing chamber.