Abstract: A control system for a dual fuel engine using primary diesel fuel and supplemental gas fuel such as propane or natural gas includes a control valve that controls supplemental fuel mixing with intake air by using an air deflectable member that controls the position of a valve controlling the admission of supplemental gas to the engine intake airstream. A damper is provided on the air flow responsive member to improve valve operation and a lost motion connection is provided between the air flow responsive member and the control valve element to permit independent movement of the elements. Normal flow of supplemental fuel to the control valve is further modulated in response to certain engine operating conditions using an engine condition comparator that generates a control signal used by the supplemental fuel pressure regulator to further modulate the supply of supplemental fuel to the intake airstream.

Abstract: A gaseous fuel carburetor includes a gas flow control valve movable both by the engine intake air stream via a vane member in the intake air duct and by a fluidic (e.g., vacuum) actuator in the valve assembly, the actuator being controllable in response to engine load demand, whereby the total gas valve opening is responsive to intake air flow and engine load. A motion damper for the valve is included, and a dual gas/liquid fuel supply system is also described wherein the air vane can be retracted to a nonobstructing position relative to the air duct when the supply of gas fuel is ceased.

Abstract: A control system for a dual fuel engine using primary diesel fuel and supplemental gas fuel such as propane or natural gas includes a control valve that controls supplemental fuel mixing with intake air by using an air deflectable member that controls the position of a valve controlling the admission of supplemental gas to the engine intake airstream. A damper is provided on the air flow responsive member to improve valve operation and a lost motion connection is provided between the air flow responsive member and the control valve element to permit independent movement of the elements. Normal flow of supplemental fuel to the control valve is further modulated in response to certain engine operating conditions using an engine condition comparator that generates a control signal used by the supplemental fuel pressure regulator to further modulate the supply of supplemental fuel to the intake airstream.

Abstract: A control system for an auxiliary gaseous fuel supply system for an internal combustion engine utilizing a primary liquid fuel supply includes a pressure regulator that is controlled by two pressure signals generated in response to engine operating conditions to enable the pressure regulator to respond more rapidly to changes in engine operating conditions. A valve in the pressure regulator is controlled by a diaphragm subjected on its opposite sides to a pair of pressure signals, one of the signals corresponding to the usual long term gas fuel demand signal which primarily controls the position of the regulator valve, the other signal corresponding to shorter term changes in intake air flow conditions in the intake air duct of the engine to augment or oppose the primary signal, depending upon instantaneous intake air flow conditions.

Abstract: A process for controlling the supply of gaseous secondary fuel to the intake air stream of an I.C. engine normally supplied with liquid primary fuel includes the steps of supplying the gaseous secondary fuel to the engine air intake stream according to a desired air-to-fuel ratio during normal engine operation by utilizing a movable air flow responsive member in the path of the air intake stream to control the position of a gas valve in the gas fuel supply system, and effecting closure of the gas valve as the engine speed controller approaches its idle or off position without positively moving the air flow responsive member. The flow of secondary gas fuel to the engine is thus reduced or stopped without altering the position of the air flow responsive member which continues to move in response to intake air flow. The gaseous fuel, if supplied to a supercharged liquid fuel burning engine, is pressurized by the supercharger system upstream of the engine intake air ports.

Abstract: A liquid and supplemental gas fuel supply system for an I.C. engine, and in particular a diesel cycle engine, includes a gas fuel control valve that meters supplemental gas fuel into the engine intake air stream in response to engine air flow using a direct air flow responsive member to control a gas valve through a lost motion connection. The position of the gas valve is moreover controllable by a separate throttle position responsive control system that moves the gas valve towards closed position as the throttle approaches the closed or idle position, and holds the gas valve closed until the throttle has moved away from the closed or idle position. The separate control motion of the gas valve is independent from the motion of the air flow responsive member and does not restrict or interfere with the movement of the latter.