US3551600A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High capacity,high side-tone suppression,4-wire conference circuit
Assignee: Telex Computer Products Inc
•
Filing: 1968-02-23
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Granted: 1970-12-29
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Expires: 1988-02-23
Abstract
No abstract record available.
Inventors
- 👤 William H Berch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:59
CPC Classifications
H; H04; H04M; H04M3/00; H04M3/42; H04M3/56; H04M3/561; H04M3/568
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) | 1973-12-28 | 1974-06-29 | 1974-12-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-12-28 | 1978-06-29 | 1978-12-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-12-28 | 1982-06-29 | 1982-12-29 | $7700.00 | Window Closed / Lapsed |