US3850600A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filter media
Assignee: MSA Safety Inc
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Filing: 1973-07-05
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Granted: 1974-11-26
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Expires: 1993-07-05
Abstract
Abstract Improved air filters of felt carrying electrically charged resinous particles comprise a felt made from a mixture of wool and acrylic fibers.
Inventors
- 👤 J Monsted
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:27
CPC Classifications
B; B01; B01D; B01D39/00; B01D39/14; B01D39/16; B01D39/1607; B01D39/1623; B01D39/1615
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
53 words
A FILTER OF FELTED FIBERS CARRYING MECHANICALLY ELECTRIFIED RESIN PARTAICLES IN WHICH THE FELT CONSISTS ESSENTIALLY OF WOOL FIBERS AND ACRYLIC FIBERS EACH FIBER BEING PRESENT IN AN AMOUNT AT LEAST ABOUT 10 PERCENT BY WEIGHT EFFECTIVE TO IMPROVE DUST COLLECTION EFFCIENCY AND THE RETENTION OF DUST COLLECTION EFFICIENCY UNDER CHARGE DEGRADING CONDITIONS.
Claim 2
Dependent Claim
53 words
A FILTER OF FELTED FIBERS CARRYING MECHANICALLY ELECTRIFIED RESIN PARTAICLES IN WHICH THE FELT CONSISTS ESSENTIALLY OF WOOL FIBERS AND ACRYLIC FIBERS EACH FIBER BEING PRESENT IN AN AMOUNT AT LEAST ABOUT 10 PERCENT BY WEIGHT EFFECTIVE TO IMPROVE DUST COLLECTION EFFCIENCY AND THE RETENTION OF DUST COLLECTION EFFICIENCY UNDER CHARGE DEGRADING CONDITIONS.
Claim 3
Dependent Claim
27 words
A filter according to claim 1 having a felt containing a minor proportion of one fiber in an amount of at least about 10 percent by weight.
Claim 4
Dependent Claim
16 words
A filter according to claim 1 having a felt containing a major proportion of acrylic fiber.
Claim 5
Dependent Claim
10 words
A filter according to claim 1 having zinc resinate particles.
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) | 1977-11-25 | 1978-05-27 | 1978-11-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-25 | 1982-05-27 | 1982-11-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-25 | 1986-05-27 | 1986-11-26 | $7700.00 | Window Closed / Lapsed |