Patent US3130274A successfully refreshed from Google Patents.
US3130274A
Expired / Lapsed
US
⏱️ 0.0 years remaining
2-or 4-wire telephone set
Assignee: TDK Micronas GmbH
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Filing: 1960-10-20
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Granted: 1964-04-21
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Expires: 1980-10-20
Abstract
No abstract record available.
Inventors
- 👤 Thomas B Norling
- 👤 John E Stewart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:16
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/58
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
90 words
A TELEPHONE CIRCUIT COMPRISING A TRANSMIT CHANNEL, A RECEIVE CHANNEL, A TELEPHONE SUBSET NETWORK INCLUDING A TRANSMITTER COUPLED TO SAID TRANSMIT CHANNEL, A RECEIVER, MEANS INDUCTIVELY COUPLING SAID RECEIVER TO SAID RECEIVE CHANNEL, MEANS FOR SPLITTING A PORTION OF THE CURRENT FLOW FROM SAID TRANSMITTER INTO TWO SUBSTANTIALLY EQUAL CURRENTS, MEANS FOR APPLYING SAID SPLIT CURRENTS ACROSS SAID INDUCTIVE MEANS IN BUCKING RELATION TO ATTENUATE TRANSFER OF SIGNALS FROM SAID TRANSMITTER TO SAID RECEIVE CHANNEL, AND MEANS FOR ENERGIZING SAID RECEIVER BY ONE OF SAID SPLIT CURRENTS TO PROVIDE SIDETONE.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1967-04-21 | 1967-10-21 | 1968-04-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-04-21 | 1971-10-21 | 1972-04-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-04-21 | 1975-10-21 | 1976-04-21 | $7700.00 | Window Closed / Lapsed |