US3188398A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transmission improvement in party-line telephone systems
Assignee: AT&T Inc
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Filing: 1961-09-27
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Granted: 1965-06-08
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Expires: 1981-09-27
Abstract
No abstract record available.
Inventors
- 👤 Busala Alessandro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:55
CPC Classifications
H; H04; H04Q; H04Q5/00; H04M; H04M1/00; H04M1/71; H04M1/715
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
125 words
IN A PARTY-LINE TELEPHONE SYSTEM, A CENTRAL OFFICE COMPRISING A SOURCE OF COMMON BATTERY CURRENT; A PLURALITY OF SUBSCRIBER LOOPS; A MAIN TRANSMISSION LINE; EACH OF SAID LOOPS HAVING ONE END CONNECTED ACROOS SAID MAIN LINE AND HAVING ANOTHER END CONNECTED ACROSS A TELEPHONE SET; SAID MAIN LINE CONNECTING SAID CENTRAL-OFFICE SOURCE OF COMMON BATTERY CURRENT TO EACH OF SAID LOOPS; AND A PLURALITY OF SEMICONDUCTOR NETWORKS INSERTED SERIALLY IN SAID LOOPS, SAID NETWORKS BEING CAPABLE OF BILATERAL CONDUCTION AND HAVING VARIOUS DIRECT-CURRENT RESISTANCES FOR DISSIPATING DIRECT-CURRENT POWER TO INSURE A SUBSTANTIALLY EQUAL FLOW OF SAID COMMON BATTERY CURRENT IN SAID LOOPS, SAID NETWORKS FURTHER HAVING ALTERNATING-CURRENT RESISTANCES WHICH ARE SUBSTANTIALLY LESS THAN SAID DIRECT-CURRENT RESISTANCES WHEN SAID COMMON BATTERY CURRENT FLOWS THROUGH SAID NETWORKS.
Claim 2
Dependent Claim
125 words
IN A PARTY-LINE TELEPHONE SYSTEM, A CENTRAL OFFICE COMPRISING A SOURCE OF COMMON BATTERY CURRENT; A PLURALITY OF SUBSCRIBER LOOPS; A MAIN TRANSMISSION LINE; EACH OF SAID LOOPS HAVING ONE END CONNECTED ACROOS SAID MAIN LINE AND HAVING ANOTHER END CONNECTED ACROSS A TELEPHONE SET; SAID MAIN LINE CONNECTING SAID CENTRAL-OFFICE SOURCE OF COMMON BATTERY CURRENT TO EACH OF SAID LOOPS; AND A PLURALITY OF SEMICONDUCTOR NETWORKS INSERTED SERIALLY IN SAID LOOPS, SAID NETWORKS BEING CAPABLE OF BILATERAL CONDUCTION AND HAVING VARIOUS DIRECT-CURRENT RESISTANCES FOR DISSIPATING DIRECT-CURRENT POWER TO INSURE A SUBSTANTIALLY EQUAL FLOW OF SAID COMMON BATTERY CURRENT IN SAID LOOPS, SAID NETWORKS FURTHER HAVING ALTERNATING-CURRENT RESISTANCES WHICH ARE SUBSTANTIALLY LESS THAN SAID DIRECT-CURRENT RESISTANCES WHEN SAID COMMON BATTERY CURRENT FLOWS THROUGH SAID NETWORKS.
References Cited (Backward Citations)
US3035122A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-06-07 | 1968-12-07 | 1969-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-06-07 | 1972-12-07 | 1973-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-06-07 | 1976-12-07 | 1977-06-08 | $7700.00 | Window Closed / Lapsed |