US Patent 9090336 Device for controlling the pitch of turboprop fan blades

The invention provides a device for controlling the pitch of the fan blades of a turboprop, the device comprising: at least one set of adjustable pitch fan blades, the set being constrained to rotate with a rotary ring mechanically linked to a rotor; a synchronizing ring coupled to each blade of the set in order to adjust its pitch; an actuator centered on the longitudinal axis of the turboprop and constrained to rotate with the rotor; and control links, each connected firstly to the actuator rod and secondly to an inside end of a cylindrical shaft via a crank capable of imparting turning movement to the shaft about its axis of revolution, an outside end of the shaft being coupled to a blade in order to adjust its pitch.