Patent US2764258A successfully refreshed from Google Patents.
US2764258A
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US
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Filter and method of fabrication
Assignee: MSA Safety Inc
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Filing: 1954-05-10
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Granted: 1956-09-25
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Expires: 1974-05-10
Abstract
No abstract record available.
Inventors
- 👤 Robert A Bub
- 👤 Earl M Becker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 04:26
CPC Classifications
B; B01; B01D; B01D46/00; B01D46/0001; B01D46/52; B01D46/521; B01D46/522; F; F24; F24F; F24F13/00; F24F13/28; B01D2265/00; B01D2265/06
Claims Analysis
Total Claims: 0
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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) | 1959-09-25 | 1960-03-26 | 1960-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-09-25 | 1964-03-26 | 1964-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-09-25 | 1968-03-26 | 1968-09-25 | $7700.00 | Window Closed / Lapsed |