US2647196A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for heating oil wells
Assignee: Union Oil Company of California
•
Filing: 1950-11-06
•
Granted: 1953-07-28
•
Expires: 1970-11-06
Abstract
No abstract record available.
Inventors
- 👤 Clayton A Carpenter
- 👤 Richard S Crog
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:14
CPC Classifications
E; E21; E21B; E21B36/00; E21B36/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1309721A
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US782233A
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US1354757A
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US2186035A
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US2244255A
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US2332708A
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US2302774A
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US2500305A
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US2548360A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-07-27 | 1957-01-26 | 1957-07-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-07-27 | 1961-01-26 | 1961-07-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-07-27 | 1965-01-26 | 1965-07-28 | $7700.00 | Window Closed / Lapsed |