US Patent 10507958 Cap

A cap includes a main unit fit onto the mouth of a double-walled container, a spout cylinder provided on the main unit, an inner stopper that is provided in the main unit, and a first inner valve. The inner stopper includes a communicating part that communicates with the inside of the inner container and the inside of the spout cylinder. The first inner valve includes a first valve body that covers the communicating part. The first valve body has passage holes. The first valve body being deformed from a closing position S toward an opening position O keeps acting as a partition between the communicating part and the spout cylinder.