Patent US1921900A successfully refreshed from Google Patents.
US1921900A
Expired / Lapsed
US
⏱️ 0.0 years remaining
One-unit ventilating system
Assignee: Individual
•
Filing: 1931-04-21
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Granted: 1933-08-08
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Expires: 1951-04-21
Abstract
No abstract record available.
Inventors
- 👤 Fordham F Wood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:50
CPC Classifications
A; A01; A01K; A01K31/00; A01K31/14; A01K31/16
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) | 1936-08-07 | 1937-02-06 | 1937-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1940-08-07 | 1941-02-06 | 1941-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1944-08-07 | 1945-02-06 | 1945-08-08 | $7700.00 | Window Closed / Lapsed |