Tamper indicating means for vacuum closures
US5289929A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 22, 1992 |
| Grant date | Mar 1, 1994 |
| Priority date | — |
| Expiry date | May 22, 2012 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB65D2401/55
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
This relates to the provision of a vacuum actuated button type closure with a tamper indicating arrangement which will visually indicate when a container has been opened or more particularly when the vacuum within a vacuum packed container has been lost. The deflectable button of the closure is utilized to squeeze a dye from a sponge like member into a layer of absorbent material so as to color the absorbent material. The absorbent material, in turn, is provided with non-absorbent areas which define indicia to indicate that an associated container has been opened. The layer of absorbent material is carried by an arched cross sectional cover and in several forms of the cover, a central portion of the cover is downwardly deformable under pressure to move the layer of absorbent material from an inoperative position to a lowered position for cooperation with the sponge like member when the button returns to its up position to effect the flow of the dye from the sponge like member into the layer of absorbent material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.