US3608563A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cigarette filter
Assignee: Individual
•
Filing: 1969-02-06
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Granted: 1971-09-28
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Expires: 1989-02-06
Abstract
Abstract A cigarette filter including crushed and screened substantially uniformly sized particles of flux calcined diatomaceous earth, the smaller particles being approximately no less than 25 percent of the size of the larger particles to prevent undesirable smoke flow restriction from filling of voids, wherein an exemplary broad size range is from approximately 100 to 425 microns and an exemplary optimum size range, when the particles are associated with conventional cellulose filters, in order to prevent undue draft restriction, is from 175 to 210 microns.
Inventors
- 👤 John B Schmitz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:45
CPC Classifications
A; A24; A24D; A24D3/00; A24D3/06; A24D3/16; A24D3/166
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
66 words
A filter for cigarettes and the like, wherein the improvement comprises: a filtering section having a cross-sectional area conforming to that of the tobacco smoke passage with which it is to be used, and including a number of confined discrete flux calcined diatomaceous earth particles in intimate contact, the size of said particles being substantially uniform and substantially between 100 microns and 425 microns in size.
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) | 1974-09-27 | 1975-03-29 | 1975-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-27 | 1979-03-29 | 1979-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-27 | 1983-03-29 | 1983-09-28 | $7700.00 | Window Closed / Lapsed |