US1540401A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vacuum oven
Assignee: AT&T Inc
•
Filing: 1920-08-24
•
Granted: 1925-06-02
•
Expires: 1940-08-24
Abstract
No abstract record available.
Inventors
- 👤 Mervin J Kelly
- 👤 Thomas R Griffith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:20
CPC Classifications
F; F27; F27D; F27D11/00; F27D11/02; H; H05; H05B; H05B3/00; H05B3/62; H05B3/64
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) | 1928-06-01 | 1928-12-01 | 1929-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1932-06-01 | 1932-12-01 | 1933-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1936-06-01 | 1936-12-01 | 1937-06-02 | $7700.00 | Window Closed / Lapsed |