Extruded zipper strips for bags
US4792240A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 6, 1987 |
| Grant date | Dec 20, 1988 |
| Priority date | — |
| Expiry date | Oct 6, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S24/50
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A bag has a reclosable zipper between wall panels and extending between side edges at the top end of the bag, the zipper comprising a continuous length of extruded profile plastic strip folded upon itself for zipper closing interengagement of its profile parts, the profile strip portions being spot welded together at the fold in the strip which may be at one of the side edges of the bag, such as a fold in the material which provides the walls of the bags. The strip may be notched out to facilitate folding. By differential mass, or differential spacing, or tilted biasing of profile parts of the zipper strip, and provision of a lateral flange of substantial width on the strip not only is interlocking of the profile parts facilitated, but an expedient is provided for restraining opening of the zipper by internal bag pressures, while permitting relatively easy opening of the bag from the outside, i.e. the top or mouth end of the bag. Visual determination of orientation of one of a plurality of profile parts of the folded zipper is provided for.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.