US3504128A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Telephone exclusion circuit
Assignee: Individual
•
Filing: 1966-09-26
•
Granted: 1970-03-31
•
Expires: 1986-09-26
Abstract
No abstract record available.
Inventors
- 👤 Charles Steinman
- 👤 Harvey Cohen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:16
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/68; H04M1/70
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2035594A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-03-30 | 1973-09-29 | 1974-03-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-03-30 | 1977-09-29 | 1978-03-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-03-30 | 1981-09-29 | 1982-03-31 | $7700.00 | Window Closed / Lapsed |