Vacuum indicating thermoplastic closure
US4678082A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 10, 1986 |
| Grant date | Jul 7, 1987 |
| Priority date | — |
| Expiry date | Jul 10, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S206/807
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A vacuum indicating thermoplastic closure for a container for the packaging of a vacuum-packed product, the top panel of the closure containing a circular inner portion which is connected to an outer annular portion by an inner annular portion with a circular hinge on the outside of the closure along a first interrupted line between the circular inner portion and the inner annular portion and another circular hinge on the inside of the closure along a second interrupted line between the inner annular portion and the outer annular portion to permit the circular inner portion to be moved relative to the outer annular portion from a first position which indicates the presence of a vacuum in the container to a second position which indicates the absence of a vacuum in the container without developing substantial tensile stresses in the top panel of the closure when the circular inner portion is in either such position, except for compressive stresses in the bridges formed by the interruptions in the first interrupted line and in the second interrupted line when the circular inner portion is in the first position, which compressive stresses assist in positively moving the circular inner…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.