Cigarette filter
AssigneeBrown & Williamson Tobacco Corporation
InventorsRobert R. Johnson, Daniel V. Cantrell
Life of this patent
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Abstract
A filter for a cigarette includes a porous filter rod circumscribed by a smoke impervious wrapper wherein the filter rod with the non-porous wrapper therearound is provided with at least one groove therein extending a preselected distance longitudinally therealong. The groove is closed at one end and is provided with an opening substantially at the other end in flow communication with the filter rod. Tipping material circumscribes the wrapper and is provided with flow-through openings therein in flow communication with the groove wherein ventilating air is the only fluid flowing through the groove when the filter is used in combination with a cigarette during normal smoke draw.
Claims6
A filter rod for a cigarette comprising:
- a porous filter rod of cylindrical configuration;
- a smoke impervious wrapper extending longitudinally along said rod from one end thereof and circumscribing said rod leaving flow-through opposed ends of said rod, said wrapper having at least one longitudinally extending groove embedded into the filter rod and that portion of the wrapper defining the groove remaining smoke impervious, said groove having an opening in one end into the filter rod, said groove extending a distance less than the length of the filter rod intermediate of both ends;
- and,
- tipping material extending longitudinally of and circumscribing said wrapper, said tipping material being air pervious and permitting ventilating air flow therethrough into said groove, said ventilating air being the only fluid flowing through said groove when the filter is used in combination with a cigarette during normal smoke draw.
Dependencies are inferred from the claim text.