US3542958A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Link circuit with high level ringing capability for electronic telephone exchange
Assignee: Stromberg Carlson Corp
•
Filing: 1967-08-22
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Granted: 1970-11-24
•
Expires: 1987-08-22
Abstract
No abstract record available.
Inventors
- 👤 Barrie Brightman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:04
CPC Classifications
H; H04; H04M; H04M19/00; H04M19/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US3251036A
Cited
US3406262A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-11-23 | 1974-05-25 | 1974-11-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-11-23 | 1978-05-25 | 1978-11-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-11-23 | 1982-05-25 | 1982-11-24 | $7700.00 | Window Closed / Lapsed |