Abstract: A child proof closure for containers having a threaded neck. A screw type cap has a first set of teeth mounted on its side the teeth being set at an angle to the axis of the cap. A drive member is loosely mounted on the cap for limited axial motion. A second set of teeth is mounted on said drive member, the teeth being angled in the same direction as the first set of teeth. When said drive member is turned in the direction to remove the cap, the interaction of said teeth lifts the drive member relative to the cap and the first and second sets of teeth disengage so that the cap cannot be removed soley by turning.