US2440439A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Permanent magnet electrodynamic transducer
Assignee: PERMOFLUX Corp
•
Filing: 1942-07-04
•
Granted: 1948-04-27
•
Expires: 1962-07-04
Abstract
No abstract record available.
Inventors
- 👤 Webster E Gilman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:01
CPC Classifications
H; H04; H04R; H04R9/00; H04R9/10
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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GB399556A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-04-27 | 1951-10-27 | 1952-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-04-27 | 1955-10-27 | 1956-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-04-27 | 1959-10-27 | 1960-04-27 | $7700.00 | Window Closed / Lapsed |