US2958078A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sound signaling system having a variable reluctance transmitter-condenser receiver transducer
Assignee: Individual
•
Filing: 1957-06-24
•
Granted: 1960-10-25
•
Expires: 1977-06-24
Abstract
No abstract record available.
Inventors
- 👤 John S Hickman
- 👤 Gordon E Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:24
CPC Classifications
H; H04; H04R; H04R19/00; H04R19/04; H04R23/00; H04R23/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2857461A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-10-25 | 1964-04-25 | 1964-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-10-25 | 1968-04-25 | 1968-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-10-25 | 1972-04-25 | 1972-10-25 | $7700.00 | Window Closed / Lapsed |