Tobacco smoke filters
US4620553A · kind A · utility
14Cited by
2References
13Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 14, 1985 |
| Grant date | Nov 4, 1986 |
| Priority date | — |
| Expiry date | May 14, 2005 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA24D3/041
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
A filter for a smoking article employing a resilient valve assembly in the path of the smoke. The valve assembly being movable in a first position in which the flow ventilating air is permitted and a second position in which the flow of air is prevented. The valve assembly being resiliently biased towards the first position and being displaceable towards the second position when a particular pressure differential is exceeded.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.