Patent US3791265A successfully refreshed from Google Patents.
US3791265A
Expired / Lapsed
US
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Apparatus for making tobacco smoke filter
Assignee: Imperial Tobacco Ltd
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Filing: 1972-01-14
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Granted: 1974-02-12
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Expires: 1992-01-14
Abstract
Abstract A tobacco smoke filter is in the form of a cylinder having a low resistance core and a high resistance end wall which cause smoke flow radially through the cylinder wall. The filter is preferably made by compacting the central core of a filter plug to form the dense end wall. Such filter plugs have an efficiency of two or three times that of a conventional filter of the same pressure drop.
Inventors
- 👤 D Westcott
- 👤 G Woodman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:35
CPC Classifications
A; A24; A24D; A24D3/00; A24D3/02; A24D3/0275; A24D3/0283
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
83 words
Apparatus for making a selectively compacted tobacco smoke filter comprising a fluted drum for holding filter plug blanks thereon, a compacting rod alignable with each flute and means for reciprocating the rod relative to each flute, the rod having a diameter which is smaller than that of a tobacco smoke filter held in a flute of the drum whereby the rod is adapted to compact only a core section of the filter, leaving an annular uncompacted wall extending around the compacted core section.
Claim 2
Dependent Claim
83 words
Apparatus for making a selectively compacted tobacco smoke filter comprising a fluted drum for holding filter plug blanks thereon, a compacting rod alignable with each flute and means for reciprocating the rod relative to each flute, the rod having a diameter which is smaller than that of a tobacco smoke filter held in a flute of the drum whereby the rod is adapted to compact only a core section of the filter, leaving an annular uncompacted wall extending around the compacted core section.
Claim 3
Dependent Claim
50 words
Apparatus as claimed in claim 1 comprising two coaxial compacting rods for each flute disposed at opposite ends of the flute, and means for reciprocating the rods simultaneously relative to each flute to compact two core sections of a double tobacco smoke filter held in a flute of the drum.
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) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |