US3894545A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filters for tobacco smoke
Assignee: Brown and Williamson Holdings Inc
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Filing: 1973-11-06
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Granted: 1975-07-15
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Expires: 1993-11-06
Abstract
Abstract The invention relates to a tobacco-smoke filter comprising regions extending substantially longitudinally of the filter and separated by a diaphragm or diaphragms of vapour-porous material into at least one region providing a through path for smoke and at least one region which is filled with carbon and is closed against smoke flow through the filter. The regions may be formed by two co-axial tubes, an inner diaphragm tube of the porous material and an outer tube of substantially smoke-impervious material. Alternatively the carbon may be contained in one or more closed bags or envelopes of the porous material enclosed within an outer tube providing a through path for the smoke.
Inventors
- 👤 Robin A Crellin
- 👤 Henry G Horewell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 12:37
CPC Classifications
A; A24; A24D; A24D3/00; A24D3/04
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
140 words
A filter for a smokeable article intended to be disposed downstream from a smokeable charge, comprising a smoke treating chamber formed by a substantially cylindrical outer wall of the filter element in close proximity to the downstream end of a smokeable charge, a longitudinally oriented vapor porous membrane mounted within said cylinder, said membrane containing a charge of particulate carbon, the upstream and downstream ends of said carbon charged membrane being effectively sealed or blocked against the passage of smoke, the space not occupied by said membrane defining longitudinally extending continuous and uninterrupted passageway or passageways extending for a length at least equal to that of the contained carbon charge, such that the smoke emerging from the downstream end of a smokeable charge preferentially courses through the said continuous and uninterrupted passageways without being forced through said contained carbon charge.
Claim 2
Dependent Claim
140 words
A filter for a smokeable article intended to be disposed downstream from a smokeable charge, comprising a smoke treating chamber formed by a substantially cylindrical outer wall of the filter element in close proximity to the downstream end of a smokeable charge, a longitudinally oriented vapor porous membrane mounted within said cylinder, said membrane containing a charge of particulate carbon, the upstream and downstream ends of said carbon charged membrane being effectively sealed or blocked against the passage of smoke, the space not occupied by said membrane defining longitudinally extending continuous and uninterrupted passageway or passageways extending for a length at least equal to that of the contained carbon charge, such that the smoke emerging from the downstream end of a smokeable charge preferentially courses through the said continuous and uninterrupted passageways without being forced through said contained carbon charge.
Claim 3
Dependent Claim
19 words
A filter according to claim 1 wherein the porous membrane is tubular and the carbon charge is contained within.
Claim 4
Dependent Claim
28 words
A filter according to claim 1 wherein the porous membrane is tubular and the carbon charge is contained within the space between the tube and said outer wall.
Claim 5
Dependent Claim
26 words
A filter according to claim 1 wherein the carbon charge is contained within at least one closed envelope of porous membrane enclosed within said outer wall.
Claim 6
Dependent Claim
22 words
A filter according to claim 4 wherein a plurality of said envelopes are disposed in a triangular form within said outer wall.
Claim 7
Dependent Claim
32 words
A filter according to claim 1 wherein the carbon charge is contained in at least one closed envelope of porous membrane, said envelope being folded within and longitudinally of said outer wall.
Claim 8
Dependent Claim
18 words
A filter according to claim 1, disposed as a centre section between two end sections of fibrous material.
Claim 9
Dependent Claim
32 words
A filter according to claim 1, wherein the vapor porous membrane is made of highly porous paper with a porosity of at least 32,000 cm3/min/10 cm2 per 10 cm water gauge pressure.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-14 | 1979-01-13 | 1979-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-14 | 1983-01-13 | 1983-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-14 | 1987-01-13 | 1987-07-15 | $7700.00 | Window Closed / Lapsed |