US2804501A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Voice warning systems
Assignee: Boeing Co
•
Filing: 1955-09-26
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Granted: 1957-08-27
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Expires: 1975-09-26
Abstract
No abstract record available.
Inventors
- 👤 Victor B Hart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:56
CPC Classifications
H; H04; H04M; H04M11/00; H04M11/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-08-26 | 1961-02-25 | 1961-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-08-26 | 1965-02-25 | 1965-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-08-26 | 1969-02-25 | 1969-08-27 | $7700.00 | Window Closed / Lapsed |