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US4390031A Expired / Lapsed US ⏱️ 0.0 years remaining

Tobacco filter

Assignee: Filtrona Richmond Inc
•
Filing: 1981-08-25
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Granted: 1983-06-28
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Expires: 2001-08-25
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Abstract

Abstract Self-sustaining, dimensionally stable, axially elongated fibrous bodies of suitable cross-sectional size and shape for use as cigarette filters are produced from a bondable continuous filamentary tow of substantially continuous thermoplastic fibers. The fibers within the filter body are oriented in an adjacent and overlapping relation to one another in generally successive layers extending generally transverse to the longitudinal axis of the filter. During fabrication the filter is passed through a cooling station of reduced cross-section so that the radially peripheral edges of the fibers are bent backward and overlap to form a smooth peripheral surface to which tip-wrap material can readily adhere without the need for a plug wrap or for coating the filter.

Inventors

  • 👤 Richard M. Berger

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 06:17
CPC Classifications
A; A24; A24D; A24D3/00; A24D3/02; A24D3/0229; A24D3/0233; A24D3/04; D; D04; D04H; D04H3/00; D04H3/02; D04H3/07

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 109 words
A smoke filter including a porous, dimensionally stable, axially elongated, generally cylindrical filter element comprising a continuous filamentary tow of substantially continuous thermoplastic fibers bonded together throughout to be self-sustaining, said fibers being oriented within said filter element in an adjacent and overlapping relation to one another in generally successive layers extending generally transverse to the longitudinal axis of said filter element, the periphery of said element comprising a smooth surface formed from outer edges of said fibers bent about respective axes extending substantially perpendicular to the longitudinal dimension of said element to overlap one another, said filter element having a substantially uniform cross-sectional diameter of approximately 8 mm.
Claim 2
Dependent Claim 109 words
A smoke filter including a porous, dimensionally stable, axially elongated, generally cylindrical filter element comprising a continuous filamentary tow of substantially continuous thermoplastic fibers bonded together throughout to be self-sustaining, said fibers being oriented within said filter element in an adjacent and overlapping relation to one another in generally successive layers extending generally transverse to the longitudinal axis of said filter element, the periphery of said element comprising a smooth surface formed from outer edges of said fibers bent about respective axes extending substantially perpendicular to the longitudinal dimension of said element to overlap one another, said filter element having a substantially uniform cross-sectional diameter of approximately 8 mm.
Claim 3
Dependent Claim 34 words
A filtered cigarette comprising, in combination, a tobacco column and a filter secured in end-to-end relationship to one end of said tobacco column, said filter including a filter element as defined in claim 1.
Claim 4
Dependent Claim 101 words
A filtered cigarette according to claim 2, wherein said filter means is secured to said one end of said tobacco column by means of a hollow cylinder of tipping paper having a plurality of perforations communicating the surrounding air with said filter element, whereby for a given draw, a mixture of smoke and ventilation air enters the smoker's mouth, said fiber orientation within said filter element providing said filter element with a resistance to flow which is higher in the longitudinal direction than in the transverse direction, thereby enabling a relatively high ratio of ventilation air to smoke in said mixture.
Claim 5
Dependent Claim 23 words
A filter rod comprising a multiplicity of filter elements as defined in claim 1, integrally connected together in end-to-end relationship to each other.
Claim 6
Dependent Claim 89 words
A smoke filter including a porous, dimensionally stable, axially elongated generally cylindrical filter element having a continuous filamentary tow of substantially continuous thermoplastic fibers bonded together throughout to be self-sustaining, said fibers being oriented within said filter element in an adjacent and overlapping relation to one another in generally successive layers extending generally transverse to the longitudinal axis of said filter element, said filter element having a smooth periphery defined by transverse outer edges of said fibers bent to extend axially along the filter element periphery in overlapped relation.
Claim 7
Dependent Claim 89 words
A smoke filter including a porous, dimensionally stable, axially elongated generally cylindrical filter element having a continuous filamentary tow of substantially continuous thermoplastic fibers bonded together throughout to be self-sustaining, said fibers being oriented within said filter element in an adjacent and overlapping relation to one another in generally successive layers extending generally transverse to the longitudinal axis of said filter element, said filter element having a smooth periphery defined by transverse outer edges of said fibers bent to extend axially along the filter element periphery in overlapped relation.
Claim 8
Dependent Claim 34 words
A filtered cigarette comprising, in combination, a tobacco column and a filter secured in end-to-end relationship to one end of said tobacco column, said filter including a filter element as defined in claim 5.
Claim 9
Dependent Claim 170 words
A smoke filter including a porous, dimensionally-stable, axially-elongated generally cylindrical filter element having a continuous filamentary tow of substantially continuous thermoplastic fibers bonded together throughout to be self-sustaining, said fibers being oriented within said filter element in an adjacent and overlapping relation to one another in generally successive layers, said filter element having a smooth periphery defined by radially outer portions of said fibers bent to extend axially along the filter element periphery in overlapped relation, wherein said filter means is secured to said one end of said tobacco column by means of a hollow cylinder of tipping paper having a plurality of perforations communicating the surrounding air with said filter element, whereby for a given draw, a mixture of smoke and ventilation air enters the smoker's mouth, said fiber orientation within said filter element providing said filter element with a resistance to flow which is higher in the longitudinal direction than in the transverse direction, thereby enabling a relatively high ratio of ventilation air to smoke in said mixture.
Claim 10
Dependent Claim 170 words
A smoke filter including a porous, dimensionally-stable, axially-elongated generally cylindrical filter element having a continuous filamentary tow of substantially continuous thermoplastic fibers bonded together throughout to be self-sustaining, said fibers being oriented within said filter element in an adjacent and overlapping relation to one another in generally successive layers, said filter element having a smooth periphery defined by radially outer portions of said fibers bent to extend axially along the filter element periphery in overlapped relation, wherein said filter means is secured to said one end of said tobacco column by means of a hollow cylinder of tipping paper having a plurality of perforations communicating the surrounding air with said filter element, whereby for a given draw, a mixture of smoke and ventilation air enters the smoker's mouth, said fiber orientation within said filter element providing said filter element with a resistance to flow which is higher in the longitudinal direction than in the transverse direction, thereby enabling a relatively high ratio of ventilation air to smoke in said mixture.
Claim 11
Dependent Claim 23 words
A filter rod comprising a multiplicity of filter elements as defined in claim 5 integrally connected together in end-to-end relationship to each other.
Claim 12
Dependent Claim 19 words
The filter according to claim 5 wherein said element has a substantially uniform cross-sectional diameter of approximately 8 mm.

References Cited (Backward Citations)

US3106501A Cited
US3190294A Cited
US3470008A Cited
US3819435A Cited
GB1297091A Cited
JPS5347599A Cited
EP0018188A1 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1986-06-27 1986-12-27 1987-06-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1990-06-27 1990-12-27 1991-06-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1994-06-27 1994-12-27 1995-06-28 $7700.00 Window Closed / Lapsed

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