(under subclass 200) Device wherein a vacuum within the closed receptacle is broken by (1) means to impart an initial opening movement to the closure which then disengages to permit the opening to be concluded by another operator or manually or (2) a separate manually operated valve means.
SEE OR SEARCH THIS CLASS, SUBCLASS:
203.01+, for a receptacle closure comprising a pressure responsive vent or valve.
271, for vents in "POP-TOP" type closures and 367 for closures in general having vent means therein.
