Patent US3774152A successfully refreshed from Google Patents.
Patent US3377784A successfully refreshed from Google Patents.
US3377784A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Portable manhole filter assembly
Assignee: Individual
•
Filing: 1966-08-11
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Granted: 1968-04-16
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Expires: 1986-08-11
Abstract
No abstract record available.
Inventors
- 👤 Walker Darrell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:01
CPC Classifications
F; F16; F16J; F16J13/00; F16J13/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2732092A
Cited
CA536416A
Cited
US836174A
Cited
US2092925A
Cited
US2695196A
Cited
US2708142A
Cited
US3015228A
Cited
US3169844A
Cited
US3289396A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-04-16 | 1971-10-16 | 1972-04-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-04-16 | 1975-10-16 | 1976-04-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-04-16 | 1979-10-16 | 1980-04-16 | $7700.00 | Window Closed / Lapsed |