Patent US1641156A successfully refreshed from Google Patents.
US2668420A
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Combination water heating and room cooling system and method employing heat pumps
Assignee: General Electric Co
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Filing: 1951-03-20
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Granted: 1954-02-09
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Expires: 1971-03-20
Abstract
No abstract record available.
Inventors
- 👤 Kemper M Hammell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:30
CPC Classifications
F; F24; F24H; F24H4/00; F24H4/02; F24H4/04; F25; F25B; F25B29/00; F25B29/003
Claims Analysis
Total Claims: 0
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US2095017A
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US2632306A
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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) | 1957-02-08 | 1957-08-10 | 1958-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-02-08 | 1961-08-10 | 1962-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-02-08 | 1965-08-10 | 1966-02-09 | $7700.00 | Window Closed / Lapsed |