Patent US3830244A successfully refreshed from Google Patents.
US3830244A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tobacco-smoke filters
Assignee: Brown and Williamson Holdings Inc
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Filing: 1972-03-31
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Granted: 1974-08-20
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Expires: 1992-03-31
Abstract
Abstract A tobacco-smoke filter comprises a tube of smoke-filtering sheet material, for example paper, extending longitudinally within and spaced radially from an outer tubular wrapper, for example an extruded smoke-impervious plastics material, the tube being blocked at both ends, while the space between the tube and the wrapper is blocked around complementary arcs at opposite ends and longitudinally in such manner that smoke entering at one end must pass through the wall of the tube twice before reaching the other end. Suitably the wrapper is formed or provided at intervals around its circumference with a number of longitudinal ribs for supporting the tube.
Inventors
- 👤 J Luke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 21:46
CPC Classifications
A; A24; A24D; A24D3/00; A24D3/02; A24D3/0275; A24D3/0283; A24D3/0279
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
109 words
A tobacco-smoke filter comprising a smoke-porous tube of smoke-filtering sheet materiAl having a wall and extending substantially longitudinally within and spaced radially from an outer tubular wrapper, a block at each end of the tube and a smoke passage chamber therebetween, and an inturned lip extending from said wrapper at opposite ends thereof through subtending complementary arcs totalling 360*, whereby the space between the tube and the wrapper is blocked around subtending complementary arcs at opposite ends and longitudinally from arc to arc so that smoke entering the said space at one end is constrained to pass through the wall of the tube twice before reaching the other end.
Claim 2
Dependent Claim
109 words
A tobacco-smoke filter comprising a smoke-porous tube of smoke-filtering sheet materiAl having a wall and extending substantially longitudinally within and spaced radially from an outer tubular wrapper, a block at each end of the tube and a smoke passage chamber therebetween, and an inturned lip extending from said wrapper at opposite ends thereof through subtending complementary arcs totalling 360*, whereby the space between the tube and the wrapper is blocked around subtending complementary arcs at opposite ends and longitudinally from arc to arc so that smoke entering the said space at one end is constrained to pass through the wall of the tube twice before reaching the other end.
Claim 3
Dependent Claim
28 words
A filter according to claim 1, wherein the wrapper has, at intervals around its circumference, a number of longitudinal internal ribs for supporting the tube along its length.
Claim 4
Dependent Claim
17 words
A filter according to claim 1, wherein the wrapper is made of an extruded smoke-impervious plastics material.
Claim 5
Dependent Claim
23 words
A filter according to claim 1, wherein said inturned lip comprises circumferential seals around semi-circular arcs offset by 180* one from the other.
Claim 6
Dependent Claim
46 words
A filter according to claim 1, wherein said inturned lip comprises circumferential seals around semi-circular arcs offset by 180* one from the other, the said seals extending circumferentially between the same longitudinal ribs, but around the said offset arcs, at the opposite ends of the filter.
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) | 1977-08-19 | 1978-02-18 | 1978-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-19 | 1982-02-18 | 1982-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-19 | 1986-02-18 | 1986-08-20 | $7700.00 | Window Closed / Lapsed |