Smoke and pollutant filtering device
US4382440A · kind A · utility
Inventors
Key dates
| Filing date | Mar 18, 1981 |
| Grant date | May 10, 1983 |
| Priority date | — |
| Expiry date | Mar 18, 2001 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D2239/065
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A smoke and pollutant filtering device comprising a mask having a filter composed of a series of contiguous, serial layers of filtering material. The filter consists of front and rear gas permeable covers, a first filter layer of pressed vegetable matter, a second filter layer comprising a layer of activated charcoal adjacent a layer of aqua filter floss, a third filter comprising a gas permeable cloth situated between layers of pressed vegetable matter, and a fourth filter layer comprising an aqua filter floss. The first through fourth filter layers are sandwiched between the front and rear gas permeable covers. The filtering device is stitched together and mounted within a fire-retardant hood shaped to fit over a human head. Elastic bands are included in the hood to maintain the hood snugly about the head when worn.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.