US3207220A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric well heater
Assignee: Individual
•
Filing: 1961-06-26
•
Granted: 1965-09-21
•
Expires: 1981-06-26
Abstract
No abstract record available.
Inventors
- 👤 Chester I Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 02:23
CPC Classifications
E; E21; E21B; E21B36/00; E21B36/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2524933A
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US2608256A
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US2597261A
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US2670802A
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US2781851A
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US2754912A
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US2994377A
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US2975721A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-09-20 | 1969-03-22 | 1969-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-09-20 | 1973-03-22 | 1973-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-09-20 | 1977-03-22 | 1977-09-21 | $7700.00 | Window Closed / Lapsed |