Envelope style filter paper
US6371307B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | May 5, 2000 |
| Grant date | Apr 16, 2002 |
| Priority date | — |
| Expiry date | May 5, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S210/08
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
In accordance with this invention, an improved filter resembling an envelope is disclosed. The filter envelope for the filter frame element includes an enclosure, the enclosure being constructed from planar first and second filter paper members lying atop one another. The first and second filter paper members each have a lateral, medial, base, and top sides, the lateral, medial, and base sides being connected to each other, respectively, to define the enclosure. The top side of the first member is not connected to the top side of the second member so as to define an opening in the enclosure to receive the frame. A closure is formed from a planar third filter paper member which is connected to a portion of the enclosure being proximate to the opening. The third filter paper member is movable between a first position and a second position, the second position being suited to close the opening.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.