Patent US2739545A successfully refreshed from Google Patents.
US3473603A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat exchanger
Assignee: Hitachi Ltd
•
Filing: 1967-01-20
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Granted: 1969-10-21
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Expires: 1987-01-20
Abstract
No abstract record available.
Inventors
- 👤 Kunio Fujie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:49
CPC Classifications
F; F28; F28D; F28D19/00; F24; F24F; F24F5/00; F24F5/0007; F28D11/00; F28D11/02; F28D11/04; Y; Y10; Y10S; Y10S165/00; Y10S165/135; Y10S165/139; Y10S165/147
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2271862A
Cited
US2616669A
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US3022046A
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US3322931A
Cited
US2991979A
Cited
US3009683A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-10-20 | 1973-04-21 | 1973-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-10-20 | 1977-04-21 | 1977-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-10-20 | 1981-04-21 | 1981-10-21 | $7700.00 | Window Closed / Lapsed |