A can end of the easy-opening type includes an end panel having a dispensing opening and a vent hole. A push-in dispensing opening plug extends into the dispensing opening and sealingly engages the end panel. A vent hole plug extends into the vent hole and sealingly engages the end panel. In one embodiment,...http://www.google.es/patents/US4024980?utm_source=gb-gplus-sharePatente US4024980 - Easy opening can end having a closure plug
