US11997A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Improvement in steam-boilers
Assignee: —
•
Filing: —
•
Granted: 1854-11-28
•
Expires: 1871-11-28
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 12:48
CPC Classifications
F; F22; F22B; F22B21/00; F22B21/02; C; C08; C08J; C08J2321/00; Y; Y10; Y10S; Y10S118/00; Y10S118/22
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) | 1857-11-27 | 1858-05-29 | 1858-11-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1861-11-27 | 1862-05-29 | 1862-11-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1865-11-27 | 1866-05-29 | 1866-11-28 | $7700.00 | Window Closed / Lapsed |