Abstract: Quick coupler for coupling a tool on a working arm of a public works machine, with two connection components equipping the tool, two coupling components for coupling with the connection components, a security component mounted for free rotation, at least one locking component, a translationally movable release component adapted to allow the security component to rotate. The release component with at least one translationally movable part adapted to be in contact with at least one surface, the shape of which is adapted to that of the security component, and a security component with at least one surface adapted to be in sliding contact with at least one complementary shaped surface of a connection component, the sliding contact inducing a rotation of the security component when the connection component moves out of its accommodation housing defined by the first coupling component.