US2987305A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methods of and apparatus for generating and transferring heat
Assignee: J V CALHOUN Co
•
Filing: 1957-05-31
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Granted: 1961-06-06
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Expires: 1977-05-31
Abstract
No abstract record available.
Inventors
- 👤 Jr John V Calhoun
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:00
CPC Classifications
F; F26; F26B; F26B13/00; F26B13/10; F26B13/14; F26B13/18; F26B13/183; F26B13/186; D; D21; D21F; D21F5/00; D21F5/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1240468A
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US1704875A
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US1945273A
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US2521371A
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US2764232A
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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) | 1964-06-05 | 1964-12-05 | 1965-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-06-05 | 1968-12-05 | 1969-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-06-05 | 1972-12-05 | 1973-06-06 | $7700.00 | Window Closed / Lapsed |