PLASTIC CLOSURE WITH PROTRUSIONS

A closure for press-on application to, and rotational removal from, a container having a cylindrical neck which includes a plurality of vertically spaced helical threads formed in the outer surface thereof in generally parallel relationship to each other. A flexible cylindrical skirt, preferably composed of a polyolefin such as polypropylene, includes a plurality of radially inwardly projecting spaced lugs that are circumferentially disposed around the inner cylindrical skirt surface and axially spaced therefrom for engagement with the threads on the cylindrical neck of the container. The lugs are composed of a deformable plastic material and are sized so that when the closure is applied to the container, an interference fit is provided between at least some of the lugs and at least some of the threads. The flexible skirt and lugs are sized to permit the closure to be applied to the container by a direct axial, press-action without requiring rotation thereof to effect the desired sealing of the closure on the container. When the closure is to be removed from the container, a rotational movement thereof causes at least some of the lugs which are at least partially received within helical grooves defined by the vertically spaced helical threads to engage upwardly inclined surfaces on the threads, thereby providing an upward camming action to the closure.