PLASTIC CAP AND CONTAINER CONSTRUCTION

摘要

A plastic container has a neck formed with a substantially horizontal flat top. On the inside of the neck proceeding downwardly there is a substantially vertical first sealing surface, then a top groove, then a very smooth second sealing surface of less diameter than the first sealing surface terminating in a lower groove and then a vertical stretch which merges into a breast which widens out to the full size of the container. On the outside of the neck proceeding downward from the flat top is a first vertical surface terminating in a horizontal inwardly extending shoulder below the elevation of the top groove, then an indented second vertical surface of lesser diameter than the first vertical surface and then an external bead having an outward-downward slanted top surface and a bottom horizontal inward-directed second shoulder at about the level of the lower groove, then a third vertical surface at about the level of the vertical stretch. The container is blow-molded or injection molded and, except at the top of the neck, where it is thicker, has a substantially uniform wall thickness. However, the second sealing surface has an "injection finish" obtained by use of a blow pin in the mold. The cap is an improvement on that shown in U. S. Patent No, 3,338,446. The upper and lower internal beads (which seat under the first and second shoulder of the neck) are interrupted in a plurality of gaps, permitting stretching of the cap to seat on the neck. The top disc has a peripheral flange which may be gripped to lift the cap when the bottom of the skirt is torn off. However the flange is flexible, bending to prevent prying off the cap when the skirt is intact.