Irreversible tamper indicator for mechanical button cap

摘要

This relates to the provision of a closure having a mechanically actuated button with a tamper indicating arrangement. A transparent panel overlies the end panel of the closure and there is provided a message indicia either on the upper surface of the button or the under surface of the transparent panel with their being carried by the transparent panel a pleated screen which shields the message indicia either by overlying the same or by blending with the message indicia in color. One end of the pleated screen is fixedly attached to the transparent panel while the opposite end has a releasable bond. When the closure is applied and the mechanical button moves towards the transparent panel, the pleated screen is clamped between the two with the result that the pleated screen is flattened and elongated rupturing the releasable bond so that once the closure is removed from the container and the button moves down away from the transparent panel, the pleated screen can collapse exposing the message indicia. This process is irreversible with the message indicia remaining exposed to indicate prior removal and replacement of the closure.