US6820A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-adjusting valve for regulating the admission of air to fan-blowers
Assignee: —
•
Filing: —
•
Granted: 1849-10-23
•
Expires: 1866-10-23
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:40
CPC Classifications
F; F24; F24F; F24F11/00; F24F11/70; F24F11/72; F24F11/74; F24F11/75; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7781; Y10T137/7784; Y10T137/7786
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) | 1852-10-22 | 1853-04-23 | 1853-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1856-10-22 | 1857-04-23 | 1857-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1860-10-22 | 1861-04-23 | 1861-10-23 | $7700.00 | Window Closed / Lapsed |