US1721938A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Recuperator and tile structure therefor
Assignee: Hartford Empire Co
•
Filing: 1925-08-27
•
Granted: 1929-07-23
•
Expires: 1945-08-27
Abstract
No abstract record available.
Inventors
- 👤 Walter O Amsler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:45
CPC Classifications
F; F28; F28F; F28F21/00; F28F21/04; Y; Y10; Y10S; Y10S165/00; Y10S165/355; Y10S165/442; Y10S165/449; Y10S165/45
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) | 1932-07-22 | 1933-01-21 | 1933-07-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1936-07-22 | 1937-01-21 | 1937-07-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1940-07-22 | 1941-01-21 | 1941-07-23 | $7700.00 | Window Closed / Lapsed |