US Patent 7520209 Servo for a gear change

Described herein is a servo for a gear change provided with a control shaft; the servo has: a first actuator, which displaces the control shaft axially along a central axis thereof and is directly coupled to the control shaft; and a second actuator, which renders a cam engaged by a pin projecting from the control shaft angularly fixed to a fixed frame to cause rotation of the control shaft about its central axis during the axial displacement; a cylindrical tubular element is provided, which is coaxial to the control shaft, receives inside it an end portion of the control shaft, supports the cam, and is pushed axially by the second actuator against the fixed frame.