Patent ID: 8177490

Claim:
A control device of variable pitch vanes in a turbomachine, comprising: a ring surrounding a casing of the turbomachine and connected by links to the variable pitch vanes; and a jack of which a piston rod is connected to the ring in order to displace the ring in rotation around the casing, the jack being mounted pivoting on the casing around a pivoting axis parallel to the axis of the casing, wherein the piston rod of the jack is connected to the ring by a connecting rod of which a first end is articulated on one end of the piston rod and a second end is articulated on the ring, around first and second axes of articulation parallel to the axis of the casing, the first axis of articulation of the end of the piston rod and of the first end of the connecting rod being guided in displacement by guiding means mounted on the casing in order to maintain the first axis of articulation at a substantially constant distance from the casing, and wherein the guiding means include a rigid arm of which one end bears the first axis of articulation of the end of the piston rod and of the first end of the connecting rod and of which the other end is mounted pivoting on the casing around an axis parallel to the axis of the casing.