Engine speed governor

Abstract

An engine speed governor for an engine having a multi-stage carburetor includes vacuum operated first and second governor actuators operatively connected to the primary and secondary throttle valves, respectively, of the carburetor and connected by separate conduits to the primary intake passage of the carburetor for venturi vacuum to effect selective closing of the primary and secondary throttle valves, and a solenoid governor valve having a normally open, first port operatively connected to the first governor actuator, a normally closed, second port operatively connected to the second governor actuator and a third port open to the atmosphere, the solenoid governor valve being connected to an engine speed sensing means whereby when the engine is below governed speed, the solenoid governor is de-energized, allowing air to bleed into the first governor actuator to keep it in a non-governing position while allowing vacuum to build up in the second governor actuator for normal operation of the secondary throttle valve, when with increasing speed the engine operates close to governed speed the solenoid governor valve is duty cycled, and when the engine operates at or above a governed speed, the solenoid governor valve is energized to allow vacuum build up in the first governor actuator to effect closing of the primary throttle valve, while allowing bleed air to flow to the second governor actuator to permit closing of the secondary throttle valve.