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US 4,393,885 AGranted
Cigarette filter
AssigneeBrown & Williamson Tobacco Corporation
InventorDonald A. Silberstein
Life of this patent
Estimating the term…
Abstract
A filter for a cigarette has a porous filter rod with a channel extending longitudinally through the filter rod. The end of the channel at the tobacco column of the cigarette is closed by a smoke impervious wall having an orifice therein of a smaller cross-sectional area than the cross-sectional area of the channel to provide flow communication between the tobacco column and the channel. The filter rod can be circumscribed with an air pervious tipping material.
Claims8
A filter for a cigarette, comprising:
- a first longitudinally extending cylindrical chamber;
- a second longitudinally extending cylindrical chamber disposed within the first chamber with a spacing between the outer wall of the second chamber and the inner wall of the first chamber, the wall of the second chamber being air impervious;
- transversely disposed smoke impervious partition means disposed at the end of the chambers interfacing with a tobacco column of the cigarette;
- and,
- means defining at least one orifice through said smoke impervious partition means for providing direct flow communication between the tobacco column of the cigarette and the interior of said second chamber whereby no smoke comes in contact with the exterior of said second chamber, the at least one orifice having a smaller cross-sectional area than the cross-sectional area of the second chamber, said first and second chambers being of substantially the same length with their ends being transversely aligned.
2 more elements
Dependencies are inferred from the claim text.