US1815618A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat exchanger
Assignee: Ross Heater & Manufacturing Co Inc
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Filing: 1931-01-29
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Granted: 1931-07-21
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Expires: 1951-01-29
Abstract
No abstract record available.
Inventors
- 👤 Harold M Graham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 18:30
CPC Classifications
F; F28; F28D; F28D7/00; F28D7/16; F28D7/163; F28D7/1638; F28F; F28F2265/00; F28F2265/26
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) | 1934-07-20 | 1935-01-19 | 1935-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1938-07-20 | 1939-01-19 | 1939-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1942-07-20 | 1943-01-19 | 1943-07-21 | $7700.00 | Window Closed / Lapsed |