Patent US3664352A successfully refreshed from Google Patents.
US3664352A
Expired / Lapsed
US
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Tobacco smoke filter
Assignee: Liggett Group LLC
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Filing: 1970-07-27
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Granted: 1972-05-23
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Expires: 1990-07-27
Abstract
Abstract Hydrogen cyanide is removed from tobacco smoke by passing the smoke through a filter containing a water-insoluble, mixed-metal carbonate of an alkaline earth metal selected from the group consisting of magnesium, calcium, strontium and barium and a transition metal selected from the group consisting of cobalt, nickel, copper and zinc.
Inventors
- 👤 Vello Norman
- 👤 Thomas B Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:43
CPC Classifications
A; A24; A24D; A24D3/00; A24D3/06; A24D3/16
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
63 words
A cigarette according to claim 1 wherein said carbonate has the formula XxYy(CO3)z wherein X is said alkaline earth metal; Y is said transition metal; x is an integer having a value of from 1 through 4, inclusive; y is an integer having a value of 1 or 2; and z is an integer having a value of from 2 through 4, inclusive.
Claim 2
Dependent Claim
31 words
A cigarette according to claim 2 wherein x has a value of 1 through 3, inclusive; y has a value of 1; and z has a value of x + y.
Claim 3
Dependent Claim
11 words
A cigarette according to claim 3 wherein said carbonate is BaNi(CO3)2.
Claim 4
Dependent Claim
11 words
A cigarette according to claim 3 wherein said carbonate is Ca3Co(CO3)4.
Claim 5
Dependent Claim
11 words
A cigarette according to claim 3 wherein said carbonate is CaCu(CO3)2.
Claim 6
Dependent Claim
11 words
A cigarette according to claim 3 wherein said carbonate is CaZn(CO3)2.
Claim 7
Dependent Claim
11 words
A cigarette according to claim 3 wherein said carbonate is Mg3Co(CO3)4.
Claim 8
Independent Claim
131 words
The method of treating tobacco smoke to reduce the hydrogen cyanide content thereof which comprises interposing in the path of the smoke stream between a tobacco charge and the mouth of the user, a charge of a coprecipitated, water insoluble carbonate, which is of an alkali earth metal carbonate and a transition metal carbonate, the alkali earth metal being selected rom the group consisting of magnesium, calcium, strontium and barium and the transition metal being selected from the group consisting of cobalt, nickel, copper and zinc, the proportion of the alkali earth metal carbonate to transition earth metal carbonate being such as to effectively reduce the hydrogen cyanide content of the smoke in an amount greater than that possible by either carbonate taken alone or by the two carbonates physically admixed.
Claim 9
Dependent Claim
63 words
A method according to claim 9 wherein said carbonate has the formula XxYy(CO3)z wherein X is said alkaline earth metal; Y is said transition metal; x is an integer having a value of from 1 through 4, inclusive; y is an integer having a value of 1 or 2; and z is an integer having a value of from 2 through 4, inclusive.
Claim 10
Dependent Claim
31 words
A method according to claim 10 wherein x has a value of 1 through 3, inclusive; y has a value of 1; and z has a value of x + y.
Claim 11
Dependent Claim
11 words
A method according to claim 11 wherein said carbonate is BaNi(CO3)2.
Claim 12
Dependent Claim
11 words
A method according to claim 11 wherein said carbonate is Ca3Co(CO3)4.
Claim 13
Dependent Claim
11 words
A method according to claim 11 wherein said carbonate is CaCu(CO3)2.
Claim 14
Dependent Claim
11 words
A method according to claim 11 wherein said carbonate is CaZn(CO3)2.
Claim 15
Dependent Claim
11 words
A method according to claim 11 wherein said carbonate is Mg3Co(CO3)4.
References Cited (Backward Citations)
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Cited
US2423688A
Cited
US2914072A
Cited
US3014880A
Cited
US3428055A
Cited
US3426763A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-23 | 1975-11-22 | 1976-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-23 | 1979-11-22 | 1980-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-23 | 1983-11-22 | 1984-05-23 | $7700.00 | Window Closed / Lapsed |