| 摘要 |
A composite closure for a container vents internal gas pressure in excess of a pre-established maximum. An insert disk fits inside an overhanging top lip of the closure. The undersurface of the top lip is recessed to present a chamber into which excess gas pressure beneath the cover can deflect the disk and thereby provide a vent under the disk. A stop on a small area of the undersurface of the top lip positively abuts the disk to prevent blocking the chamber if the closure is overtightened. |
