A seat adjuster device for setting a first part of a motor vehicle seat relative to a second part comprising a curved piece connected to the first part and having a center and a regular front face; and a support piece connected to the second part and mounted to rotate about the center, and having a first and second clamping bevel. The fiber generally comprises a liquid crystal core and a polymer shell wherein the liquid crystal is responsive to chemical changes, thermal and mechanical effects, as well as electrical and magnetic fields. The mount is comprised of a pivoting lever with brace that grips the rib between vertically spaced coupler coring holes and a lever tip that contacts the inner wall of the coupler top coring hole, a pad that bears against the exterior face of the coupler guard arm side and a mechanism that forcibly pivots the lever tip towards the pad on an axis roughly parallel to the coupler axis.