Patent ID: 8376693

Claim:
A variable vane assembly comprising: a unison ring having a radial stiffness that varies in a circumferential direction thereof; an array of variable vanes coupled to the unison ring for common displacement upon rotation of the unison ring about its central axis by means of a force applied at a first drive point and at a second drive point on the unison ring; a first actuator that is: i) configured to rotate the unison ring about its central axis, and ii) connected to the unison ring at the first drive point, the first drive point being positioned in a region of minimum stiffness on the unison ring; and a second actuator that is: i) configured to rotate the unison ring about its central axis, and ii) connected to the unison ring at the second drive point, the second drive point being positioned in a region that is diametrically opposite to the region of minimum stiffness.