US3179750A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pbx in-dialing circuit
Assignee: AT&T Inc
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Filing: 1960-12-23
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Granted: 1965-04-20
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Expires: 1980-12-23
Abstract
No abstract record available.
Inventors
- 👤 William M Reilly
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:18
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/58; H04Q3/62; H04Q3/625; H04M; H04M3/00; H04M3/42; H04M3/58
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
110 words
IN COMBINATION, A CENTRAL OFFICE AND A PBX INTERNECTED BY A LINE, MEANS AT SAID CENTRAL OFFICE RESPONSIVE TO AN INCOMING CALL DIRECTED TO SAID PBX FOR IMPRESSING RINGING CURRENT ON SAID LINE, MEANS AT SAID PBX FOR PRESENTING A LOW IMPEDANCE TO SAID RINGING CURRENT TO EFFECT ITS REMOVAL FROM SAID LINE, MEANS AT SAID CENTRAL OFFICE RESPONSIVE TO THE REMOVAL OF SAID RINGING CURRENT TO INTERCONNECT SAID CENTRAL OFFICE WITH SAID LINE ON A TALKING BASIS, MEANS AT SAID PBX RESPONSIVE TO SAID TALKING INTERCONNECTING FOR APPLYING DIAL TONE TO SAID LINE TO SIGNIFY THAT THE DIGITS OF A WANTED EXTENSION MAY BE DIALED, MEANS AT SAID CENTRAL
Claim 2
Dependent Claim
110 words
IN COMBINATION, A CENTRAL OFFICE AND A PBX INTERNECTED BY A LINE, MEANS AT SAID CENTRAL OFFICE RESPONSIVE TO AN INCOMING CALL DIRECTED TO SAID PBX FOR IMPRESSING RINGING CURRENT ON SAID LINE, MEANS AT SAID PBX FOR PRESENTING A LOW IMPEDANCE TO SAID RINGING CURRENT TO EFFECT ITS REMOVAL FROM SAID LINE, MEANS AT SAID CENTRAL OFFICE RESPONSIVE TO THE REMOVAL OF SAID RINGING CURRENT TO INTERCONNECT SAID CENTRAL OFFICE WITH SAID LINE ON A TALKING BASIS, MEANS AT SAID PBX RESPONSIVE TO SAID TALKING INTERCONNECTING FOR APPLYING DIAL TONE TO SAID LINE TO SIGNIFY THAT THE DIGITS OF A WANTED EXTENSION MAY BE DIALED, MEANS AT SAID CENTRAL
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) | 1968-04-19 | 1968-10-19 | 1969-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-04-19 | 1972-10-19 | 1973-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-04-19 | 1976-10-19 | 1977-04-20 | $7700.00 | Window Closed / Lapsed |