The movable jaw can rock because of the link connecting the movable jaw to the main bar. The adjusting screw can also rock. A spring works to keep the jaws spread within the limits of the adjustment. McKibbon improved this patent with subsequent patents (nos. 1,709,589, 1,730,671, and 1,872,780) which eventually were realized as the "KIBBON KATCH-KWIK" pipe wrench.