US3418794A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Furnace filter with replaceable filter element
Assignee: CHARLES DORIA ROBERTS
•
Filing: 1966-12-21
•
Granted: 1968-12-31
•
Expires: 1986-12-21
Abstract
No abstract record available.
Inventors
- 👤 Roberts Charles Doria
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:47
CPC Classifications
B; B01; B01D; B01D46/00; B01D46/10
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1104151A
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US1771173A
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US2182501A
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US2209741A
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US2335428A
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US2783834A
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US2895565A
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US3076303A
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US2964127A
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US3111489A
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US3150945A
Cited
US3280984A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-12-31 | 1972-07-01 | 1972-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-12-31 | 1976-07-01 | 1976-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-12-31 | 1980-07-01 | 1980-12-31 | $7700.00 | Window Closed / Lapsed |