US2122256A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat exchange apparatus
Assignee: Individual
•
Filing: 1936-03-02
•
Granted: 1938-06-28
•
Expires: 1956-03-02
Abstract
No abstract record available.
Inventors
- 👤 Charles H Leach
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 00:11
CPC Classifications
F; F28; F28D; F28D7/00; F28D7/16; F28D7/1615; F28D7/1623; F28D7/0058; F28D21/00; F28D2021/0019; F28D2021/0059
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1941-06-27 | 1941-12-27 | 1942-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1945-06-27 | 1945-12-27 | 1946-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1949-06-27 | 1949-12-27 | 1950-06-28 | $7700.00 | Window Closed / Lapsed |