Patent ID: 8277182

Claim:
A system for adjusting the pitch of a variable pitch propeller, the system comprising: a duct assembly mounted to an exterior of a deck of a vehicle; a hub assembly disposed within the duct assembly, the hub assembly comprising: a hub rotatably driven by a propeller shaft extending from an engine mounted to the vehicle; an actuator connected to the hub; and a plurality of propeller blades connected to the actuator with at least one mechanical connection; a valve assembly disposed within the duct assembly and in fluid communication with the actuator, the valve assembly comprising: a piston pilot valve; and a proportional valve having a tip that contacts the piston pilot valve, wherein an opening is created within the proportional valve depending on a location of the tip; and a fluid supply assembly in fluid communication with the valve assembly through a plurality of hydraulic lines extending through the deck, the fluid supply assembly comprising a valve control mechanism isolated from the valve assembly and the hub assembly within an interior of the deck; wherein the valve control mechanism provides a variable hydraulic pressure control signal to the valve assembly, the valve assembly transfers fluid to the actuator as a function of the variable hydraulic pressure control signal, and the mechanical connection adjusts the pitch of the propeller blades relative to fluid pressure in the actuator.