US3721771A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Telephone range expander
Assignee: Individual
•
Filing: 1969-12-12
•
Granted: 1973-03-20
•
Expires: 1989-12-12
Abstract
Abstract AN EXTENSION TELEPHONE IS COUPLED TO A TELEPHONE LINE THROUGH A CONTROL UNIT WHICH RECEIVES AND FORWARDS BY RADIO INCOMING CALLS AND IS FULLY CONTROLLED FROM THE EXTENSION UNIT FOR OUTGOING CALLS. INCOMING CALLS RING THE REMOTE MOBILE UNIT WHICH IS THEN COUPLED FOR CONVERSATION TO THE LINE THROUGH A CONTROL UNIT ACTUATED FROM THE EXTENSION UNIT. THE MOBILE UNIT TRANSMITS ACTUATION AND DIALING SIGNALS TO THE CONTROL UNIT FOR OUTGOING CALLS FROM THE MOBILE UNIT IN RESPONSE TO SUCCESSIVELY TRANSMITTED TONE MODULATIONS TO DIAL ANY PARTY ON THE TELEPHONE LINE AND THEREUPON CONNECTS THE MOBILE MICROPHONE AND RECEIVER DIRECTLY TO THE LINE. D R A W I N G
Inventors
- 👤 G Greneker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 09:26
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/72; H04M1/725; H04M1/72502; H04M1/72505
Claims Analysis
Total Claims: 0
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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) | 1976-03-19 | 1976-09-18 | 1977-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-19 | 1980-09-18 | 1981-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-19 | 1984-09-18 | 1985-03-20 | $7700.00 | Window Closed / Lapsed |