Patent US2998860A successfully refreshed from Google Patents.
US2998860A
Expired / Lapsed
US
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Sound silencing and filtering apparatus
Assignee: Individual
•
Filing: 1958-02-14
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Granted: 1961-09-05
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Expires: 1978-02-14
Abstract
No abstract record available.
Inventors
- 👤 Wilhelm S Everett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:00
CPC Classifications
F; F01; F01N; F01N1/00; F01N1/02; F01N1/04; B; B24; B24D; B24D5/00; B24D5/02; B24D5/04; F01N1/08; F01N1/10; F01N2490/00; F01N2490/15; F01N2490/155
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1366632A
Cited
US1595711A
Cited
US1909511A
Cited
DE736944C
Cited
US2325905A
Cited
US2389988A
Cited
US2609886A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-09-04 | 1965-03-06 | 1965-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-09-04 | 1969-03-06 | 1969-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-09-04 | 1973-03-06 | 1973-09-05 | $7700.00 | Window Closed / Lapsed |