US3910288A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Programmed filter
Assignee: Brown and Williamson Holdings Inc
•
Filing: 1974-07-05
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Granted: 1975-10-07
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Expires: 1994-07-05
Abstract
Abstract A filter is provided for a smoking tobacco product, the filter having one or more channels which by-pass the main body of filtering material such that a portion of the smoke is caused to flow through the channel and a relatively short portion of the filter in the earlier puffs, while essentially all of the smoke flows through the main body of the filtering material in later puffs. Through the gradual change from a portion of the smoke flowing through the channel to all of the smoke flowing through the main filter body, the filter accomplishes a nearly uniform per puff delivery of total particulate matter, through a relatively steady increase in filter efficiency.
Inventors
- 👤 James R Hammersmith
- 👤 Ii Philip H Cogbill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:19
CPC Classifications
A; A24; A24D; A24D3/00; A24D3/04
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
189 words
A filtering element for a smoking product comprising a. a main filtration element, containing filtration material and having a mouthpiece end, for disposition in substantial alignment with a tobacco section and b. channel filter means of an initial flow resistance equal to or lower than said main filtration element for causing predetermined proportion of the smoke from the tobacco section to initially by-pass a part of the filtration material and move through said channel filter means and further causing a predetermined increasing proportion of the smoke to pass through said filtration material as the tobacco section is smoked, due to increasing flow resistance through said channel filter means, whereby the total particulate matter per puff delivered to the smoker remains essentially constant during smoking of the tobacco section, said channel means including at least one channel having essentially smoke impervious walls, an open upstream end communicating with the tobacco section, and a single orifice at the downstream end of said channel adjacent said filtration material at a position short of the mouthpiece end of said main filtration element, the area of the orifice is from about 0.07 to 6.0mm2.
Claim 2
Dependent Claim
189 words
A filtering element for a smoking product comprising a. a main filtration element, containing filtration material and having a mouthpiece end, for disposition in substantial alignment with a tobacco section and b. channel filter means of an initial flow resistance equal to or lower than said main filtration element for causing predetermined proportion of the smoke from the tobacco section to initially by-pass a part of the filtration material and move through said channel filter means and further causing a predetermined increasing proportion of the smoke to pass through said filtration material as the tobacco section is smoked, due to increasing flow resistance through said channel filter means, whereby the total particulate matter per puff delivered to the smoker remains essentially constant during smoking of the tobacco section, said channel means including at least one channel having essentially smoke impervious walls, an open upstream end communicating with the tobacco section, and a single orifice at the downstream end of said channel adjacent said filtration material at a position short of the mouthpiece end of said main filtration element, the area of the orifice is from about 0.07 to 6.0mm2.
Claim 3
Dependent Claim
20 words
The filtering element of claim 1 wherein said channel means is a single channel formed in said main filtration element.
Claim 4
Dependent Claim
19 words
The filtering element of claim 2 wherein said channel is formed on the periphery of said main filtration element.
Claim 5
Dependent Claim
17 words
The filtering element of claim 2 wherein said channel is formed axially within said main filtration element.
Claim 6
Dependent Claim
17 words
The filtering element of claim 2 wherein the area of the orifice is from 0.5 to 3.5mm2.
Claim 7
Dependent Claim
11 words
The filtering element of claim 2 wherein said channel is tapered.
Claim 8
Dependent Claim
32 words
The filtering element of claim 1 wherein said channel means is a plurality of channels, each having an open end communicating with said tobacco section and an orifice adjacent the filtration material.
Claim 9
Dependent Claim
11 words
The filtering element of claim 7 wherein two channels are formed.
Claim 10
Dependent Claim
16 words
The filtering element of claim 7 wherein each of said channels is of the same length.
Claim 11
Dependent Claim
13 words
The filtering element of claim 7 wherein the channels are of different lengths.
Claim 12
Dependent Claim
21 words
The filtering element of claim 10 wherein the length of one channel is greater than the length of the other channel.
Claim 13
Dependent Claim
17 words
The filtering element of claim 1 wherein the channel filter means lies outside the main filtration element.
References Cited (Backward Citations)
US2958328A
Cited
US3270750A
Cited
US3428050A
Cited
US3596664A
Cited
US3651819A
Cited
US3768489A
Cited
US3752165A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-06 | 1979-04-07 | 1979-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-06 | 1983-04-07 | 1983-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-06 | 1987-04-07 | 1987-10-07 | $7700.00 | Window Closed / Lapsed |