US3371165A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Telephone central office loop-around test security circuit
Assignee: AT&T Inc
•
Filing: 1965-04-15
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Granted: 1968-02-27
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Expires: 1985-04-15
Abstract
No abstract record available.
Inventors
- 👤 Harold W Earle
- 👤 Verne E Munson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:18
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/46
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
39 words
APPARATUS FOR TESTING TWO-WAY LINE TRANSMISSION LOSS COMPRISING, IN COMBINATION, FIRST AND SECOND TRANSMISSION PATHS, FOR CONNECTING SAID PATHS, AND MEANS RESPONSIVE TO SPEECH SIGNALS ON ONE OF SAID PATHS FOR INSERTING A RELATIVELY HIGH IMPEDANCE BETWEEN SAID PATHS.
Claim 2
Dependent Claim
39 words
APPARATUS FOR TESTING TWO-WAY LINE TRANSMISSION LOSS COMPRISING, IN COMBINATION, FIRST AND SECOND TRANSMISSION PATHS, FOR CONNECTING SAID PATHS, AND MEANS RESPONSIVE TO SPEECH SIGNALS ON ONE OF SAID PATHS FOR INSERTING A RELATIVELY HIGH IMPEDANCE BETWEEN SAID PATHS.
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) | 1971-02-26 | 1971-08-28 | 1972-02-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-02-26 | 1975-08-28 | 1976-02-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-02-26 | 1979-08-28 | 1980-02-27 | $7700.00 | Window Closed / Lapsed |