US3819868A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Common control switching network for telegraph and telephone exchange
Assignee: NEC Corp
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Filing: 1972-12-06
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Granted: 1974-06-25
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Expires: 1992-12-06
Abstract
Abstract Each link of a common control switching network is capable of transmitting either a telegraph or a telephone signal. Each telegraph and telephone interface device is divided into two portions, one for the transmission of telegraph or telephone signals and the other for transmitting a control signal accompanying the telegraph or the telephone signal between the remaining portion of the interface device and common control equipment. Responsive to the control signal accompanying either telegraph or the telephone signals, the common control equipment makes one of the links establish a connection between two of the interface devices for transmission of the telegraph or the telephone signal accompanied by the control signal between the two interface devices.
Inventors
- 👤 H Sasahara
- 👤 K Ozeki
- 👤 H Mochizuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:18
CPC Classifications
H; H04; H04M; H04M11/00; H04M11/06; H04Q; H04Q3/00; H04Q3/42
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
181 words
A common control switching network for direct-current and alternating-current signals including a link device, a plurality of direct-current devices each capable of conveying a directcurrent signal and a control signal accompanying said directcurrent signal, a plurality of alternating-current devices each capable of conveying an alternating-current signal and a control signal accompanying said alternating-current signal, and common control equipment, responsive to the control signal accompanying a direct-current signal, for causing said link device to establish a connection between two of said direct-current devices and responsive to the control signal accompanying an alternatingcurrent signal for causing said link device to establish a connection between two of said alternating-current devices wherein the improvement comprises: a plurality of links provided in said link device, each capable of transmitting either direct-current or alternating-current signals, and an interface device provided in each of said direct-current and alternating-current devices for transmitting the control signal accompanying a direct-current or alternating-current signal between the direct-current or alternating-current device producing the control signal and said common control equipment, said common control equipment causing one of said links to establish said connection.
Claim 2
Dependent Claim
181 words
A common control switching network for direct-current and alternating-current signals including a link device, a plurality of direct-current devices each capable of conveying a directcurrent signal and a control signal accompanying said directcurrent signal, a plurality of alternating-current devices each capable of conveying an alternating-current signal and a control signal accompanying said alternating-current signal, and common control equipment, responsive to the control signal accompanying a direct-current signal, for causing said link device to establish a connection between two of said direct-current devices and responsive to the control signal accompanying an alternatingcurrent signal for causing said link device to establish a connection between two of said alternating-current devices wherein the improvement comprises: a plurality of links provided in said link device, each capable of transmitting either direct-current or alternating-current signals, and an interface device provided in each of said direct-current and alternating-current devices for transmitting the control signal accompanying a direct-current or alternating-current signal between the direct-current or alternating-current device producing the control signal and said common control equipment, said common control equipment causing one of said links to establish said connection.
References Cited (Backward Citations)
US3227806A
Cited
US3475557A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-24 | 1977-12-24 | 1978-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-24 | 1981-12-24 | 1982-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-24 | 1985-12-24 | 1986-06-25 | $7700.00 | Window Closed / Lapsed |