Bottle stopper with pressure indicator

A stopper for use in the neck of a bottle, the bottle having a vacuum therein, the stopper comprising:

• a resilient outer body including a cylindrical sleeve portion disposed intermediate upper and lower flange portions, the sleeve portion and lower flange portion being adapted for insertion into the bottle neck, the sleeve portion and the upper flange portion defining an axial bore having an interior surface, the lower flange portion extending radially inward from the interior surface to an axial orifice having a sealing surface, the lower flange portion having a bottom biasing surface adapted for being acted on by the vacuum in bottle, the sleeve portion having an outer surface adapted for forming an air-tight and fluid-tight seat with the bottle neck;
• a substantially rigid inner body including a sleeve portion extending longitudinally from an upper flange portion and defining a longitudinally extending opening, the upper flange portion of the inner body being disposed within the bore in the upper flange portion of the outer body, the sleeve portion of the inner body being disposed within the bore in the sleeve portion of the outer body;
• and
• a valve actuator including an upper operator portion connected to a lower valve body portion by a longitudinally extending shaft portion, the shaft portion having an indicator disposed proximate to the operator portion, the lower valve body portion and at least a part of the shaft portion being disposed within the opening of the inner body, the valve body portion being sealingly engageable with the sealing surface of the orifice to close the orifice;
• wherein the vacuum in the bottle acts on the biasing surface of the lower flange portion of the outer body to bias the lower flange portion of the outer body and the valve actuator downward into the bottle neck in opposition to a resilience force, whereby the indicator is withdrawn within the opening of the inner body when the vacuum is greater than a predetermined value and the indicator is visible above the inner body when the vacuum is less than the predetermined value.