Replacement cap for vessel

摘要

In a replacement cap for a vessel, in which a cap body 2 is mounted on a mouth portion 1a of a vessel 1 so as to be replaceable so that a liquid in the vessel 1 can be drunk through a tube 5 provided on the cap body 2, the cap body 2 is provided with an air supply port 4 having cup-shaped valve means 10 which is closed normally and is opened to supply the outside air into the vessel 1 when the interior of the vessel 1 becomes at a negative pressure. Since the valve means 10 is opened to supply the outside air into the vessel 1 when the interior of the vessel 1 becomes at a negative pressure, a liquid in the vessel 1 can be drunk smoothly through the tube 5.