|
| US4433696 | 2 Oct 1981 | 28 Feb 1984 | Philip Morris Incorporated | Variable dilution filter |
| US4526183 | 22 Feb 1984 | 2 Jul 1985 | Philip Morris Incorporated | Filter cigarette |
| US4527573 | 5 Nov 1982 | 9 Jul 1985 | Philip Morris Incorporated | Filter cigarette |
| US4532943 | 30 Sep 1982 | 6 Aug 1985 | Philip Morris Incorporated | Adjustable filter cigarette |
| US4559955 | 20 Jun 1983 | 24 Dec 1985 | | Controlled air bleed cigarette holder |
| US4570649 | 22 Feb 1984 | 18 Feb 1986 | Philip Morris Incorporated | Filter cigarette |
| US4638820 | 3 Feb 1986 | 27 Jan 1987 | R. J. Reynolds Tobacco Company | Puff control cigarette |
| US4649941 | 16 Dec 1985 | 17 Mar 1987 | R. J. Reynolds Tobacco Company | Adjustable air dilution cigarette exhibiting controlled pressure drop |
| US4649944 | 14 Aug 1984 | 17 Mar 1987 | Philip Morris Incorporated | Filter cigarette |
| US4649945 | 5 Dec 1985 | 17 Mar 1987 | R. J. Reynolds Tobacco Company | Adjustable air dilution cigarette exhibiting controlled pressure drop |
| US4898190 | 1 Mar 1989 | 6 Feb 1990 | R. J. Reynolds Tabacco Company | Adjustable air dilution cigarette with pressure drop compensation |
| US4949736 | 16 Mar 1988 | 21 Aug 1990 | R. J. Reynolds Tobacco Company | Variable ventilation mouthpiece for a smoking article |
| US6318376 | 7 Dec 1999 | 20 Nov 2001 | | Filter tip structure for cigarette |
| USRE32221 | 2 Oct 1984 | 12 Aug 1986 | | Variable dilution filter |
