Child-resistant closure

Abstract

A child-resistant closure for a container having a screw threaded neck, includes a cap having an end wall and a depending, cylindrical skirt with screw threads therein for mating cooperation with the screw threads on the container to releasably secure the cap to the container. Interengaging, selectively releasable detent members are formed on the cap and container for resisting removal of the cap by a child, but enabling an adult to remove the cap. The detent members include a plurality of detents on the cap and a cooperating detent on the container, wherein the detents have first cooperating, interengagable surfaces to enable the detents to move past one another in a cap tightning direction, and second cooperating, interengagable surfaces to prevent movement of the detents past one another in a cap loosening direction. The detents on the cap have different lengths in a direction axially of the cap, with the leading detent being longest and the trailing detent being shortest, whereby any of the detents will engage the detent on the container with substantially equal area within a predetermined range of rotational positions of the cap on the container. The detent on the container is carried by a movable, flexible release member which flexes to permit the detents to move past one another in a cap tightning direction, and the release member has an at rest position with the detents interengaged to prevent removal of the cap. The release member is constructed to be easily manually flexed in a direction to disengage the detents and thus enable the cap to be removed.