US2903153A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Head closure construction for heat exchanger
Assignee: Griscom Russell Co
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Filing: 1957-03-04
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Granted: 1959-09-08
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Expires: 1977-03-04
Abstract
No abstract record available.
Inventors
- 👤 Clarence G Root
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 08:44
CPC Classifications
F; F28; F28F; F28F9/00; F28F9/02; F28F9/0202; F22; F22B; F22B37/00; F22B37/02; F22B37/22; F22G; F22G3/00; F22G3/009
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-09-07 | 1963-03-09 | 1963-09-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-09-07 | 1967-03-09 | 1967-09-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-09-07 | 1971-03-09 | 1971-09-08 | $7700.00 | Window Closed / Lapsed |