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Patent US3374448A successfully refreshed from Google Patents.
US3374448A
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High efficiency contiguous comb filter
Assignee: Damon Engineering Inc
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Filing: 1964-05-25
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Granted: 1968-03-19
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Expires: 1984-05-25
Abstract
No abstract record available.
Inventors
- 👤 Carl R Hurtig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:17
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/0023; H03H9/0095; H03H7/00; H03H7/46; H03H9/46; H03H9/54; H03H9/58; H03H9/60
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2249415A
Cited
US3054968A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-03-19 | 1971-09-18 | 1972-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-03-19 | 1975-09-18 | 1976-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-03-19 | 1979-09-18 | 1980-03-19 | $7700.00 | Window Closed / Lapsed |