Abstract: An adjustment device for adjusting a lever arm located inside a machine frame wherein the lever arm is pivotally mounted to the frame at a first location and is spring biased against a stop at a second location of the frame. The device comprises a resilient sleeve having a shank portion adapted to extend through an aperture in the frame to act as the stop, and a head portion of larger diameter then the diameter of the aperture in the frame. The shank portion has a threaded section and a non-threaded section, the non-threaded section having a length greater than the frame thickness at the aperture, wherein the lever arm pivots as a screw extending axially through the sleeve is turned in the threaded section.