U.S. Patent Specifications

In an aircraft having adjustable pitch propellers with pitch control shafts projecting therefrom, means for simultaneously rotating said shafts either similarly or oppositely as desired comprising : a wheel carried by each of said shafts ; a tiltable pulley head ; a pair of end pulleys at each extremity of said head ; a pair of middle pulleys at the axis of said head ; an endless flexible medium trained about said wheels and about all of said pulleys so that when said head is tilted in one direction, it will rotate said control shafts oppositely, and when said middle pulleys alone arc rotated they will rotate said control shafts similarly ; and means for rotating said middle pulleys.