Patent attributes
A metallic pilfer-proof cap, in which the skirt of a skirt portion of a cap can be so separated by a weakening portion having horizontal slits and bridges formed alternately in the circumferential direction of the cap that the skirt may be left in a ring shape as a pilfer-proof band on the side of a container mouth. The horizontal slits formed by shearing in the transverse direction from the outside to leave the bridges are offset radially more inward of the cap at the portion above a shearing plane than at the portion below the shearing plane so that the bridges are formed on the upper side of the shearing plane of the horizontal slits. The upper end portion, as located on the lower side of the shearing plane, of the pilfer-proof band is made to have an internal diameter larger than the maximum external diameter of the annular bulging portion which is formed at the container mouth for retaining the pilfer-proof band.