Cigarette filters
US4175571A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 29, 1977 |
| Grant date | Nov 27, 1979 |
| Priority date | — |
| Expiry date | Aug 29, 1997 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA24F13/04
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
A cigarette filter includes a barrel, a mouthpiece at one end and a cigarette-receptive tip at the other. A restricted orifice extends through a transverse wall within the barrel. An air inlet extends through the barrel wall at a location toward the mouthpiece from the transverse wall. Received within the barrel is a stem that defines a passage for the flow of smoke, and the inlet also communicates with that passage. The stem includes a nose which is spaced from the outlet end of the orifice and defines a collection area for particulate matter included in the smoke. A system concept includes a combination of a plurality of such filters in each successive one of which the orifice is of respectively decreased diameter and the air inlet is of respectively increased diameter. The relationship of those diameters is such that different ones of the filters establish a substantially constant impedance to the drawing of smoke and air through the mouthpiece.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.