US3917907A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methods and apparatus for 4-wire switching
Assignee: Northeast Electronics Corp
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Filing: 1971-01-12
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Granted: 1975-11-04
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Expires: 1991-01-12
Abstract
Abstract For the purpose of establishing effective 4-wire communication over a 2-wire circuit, particularly a 2-wire switching circuit, between two 4-wire circuits, adapter circuits are inserted between each of the terminals of the 4-wire circuits and their associated 4-wire terminal sets on both sides of the 2-wire circuit. When two so adapted 4-wire circuits are interconnected by the 2-wire circuit, the adapters upon completion of a call automatically insert a local carrier modulator on one side and a local carrier demodulator on the other side of the 2-wire circuit for the traffic flowing from the call originating side to the destination side. The reverse direction traffic is handled in conventional manner. Tone signals are used by the adapters to identify adapted circuits and the local modulators and demodulators are inserted in the circuit only when two adapted 4wire circuits are interconnected. In a modification, the adapters are activated only if a separate tone signal is received from the ultimate call destination point.
Inventors
- 👤 Everhard H B Bartelink
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:13
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/38; H04B1/40; H04B1/50; H04B1/52; H04Q; H04Q11/00; H04Q11/02
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
160 words
A method of providing effective 4-wire operation through a 2wire communication circuit upon connecting the same between a pair of 4-wire communication circuits, which comprises the steps of: connecting said 2-wire circuit between a first and a second 4-wire circuit, and upon said connection, seNding a control signal from each of said 4-wire circuits, to the other through said 2-wire circuit, detecting at each of said 4-wire circuits, the control signal sent thereto, in response thereto modulating on a local carrier the intelligence signal received in the receiving path of the first of said 4-wire circuits to form a modulated carrier wave signal, transmitting said modulated signal over said 2-wire circuit to the second said 4-wire circuit and demodulating the same in the transmitting path thereof to recover said intelligence signal, and transmitting the intelligence signal received in the receiving path of said second 4-wire circuit over said 2-wire circuit to the transmitting path of the first said 4-wire circuit.
Claim 2
Independent Claim
160 words
A method of providing effective 4-wire operation through a 2wire communication circuit upon connecting the same between a pair of 4-wire communication circuits, which comprises the steps of: connecting said 2-wire circuit between a first and a second 4-wire circuit, and upon said connection, seNding a control signal from each of said 4-wire circuits, to the other through said 2-wire circuit, detecting at each of said 4-wire circuits, the control signal sent thereto, in response thereto modulating on a local carrier the intelligence signal received in the receiving path of the first of said 4-wire circuits to form a modulated carrier wave signal, transmitting said modulated signal over said 2-wire circuit to the second said 4-wire circuit and demodulating the same in the transmitting path thereof to recover said intelligence signal, and transmitting the intelligence signal received in the receiving path of said second 4-wire circuit over said 2-wire circuit to the transmitting path of the first said 4-wire circuit.
Claim 3
Dependent Claim
62 words
A method according to claim 1, wherein said control signals are sent and detected, by transmitting a first said control signal from said second 4-wire circuit to the first said 4-wire circuit, and detecting said first control signal thereat, thence causing the second said control signal to be transmitted from said first to said second 4-wire circuit and detecting the same thereat.
Claim 4
Dependent Claim
80 words
A method according to claim 2 wherein said second of said 4-wire communication circuits interconnects with one or more additional 4-wire circuits through additional 2-wire switching circuits, and wherein an audio control signal is sent from the last of said additional 4-wire circuits to said first 4-wire circuit, and wherein said second control signal is transmitted from said first of said 4-wire circuits when both said control signal and said audio control signal are received at said first 4-wire circuit.
Claim 5
Dependent Claim
39 words
A method according to claim 2 wherein said first control signal is sent upon completion of said interconnection between said two 4-wire communication circuits and then transmitting said first control signal in response to said completion of the interconnection.
Claim 6
Dependent Claim
42 words
A method according to claim 4 wherein said first control signal is transmitted for a relatively short interval, and the modulating of the intelligence signal in the receiving path of said first 4-wire communication circuit is continued until said interconnection is terminated.
Claim 7
Independent Claim
138 words
A method of interconnecting a first and a second 4-wire circuit through a 2-wire interconnecting circuit in which at least the first of said 4-wire circuits is equipped with an adapter for transmitting a local carrier through said 2-wire circuit to said second 4-wire circuit, said method comprising: upon completion of said interconnection, the transmission from said second to said first 4-wire circuit of a first control signal if said second circuit is equipped with such an adapter, and upon receipt and detection of said first control signal by said first circuit, said first circuit switches in its said local carrier and applies the signals received on the first 4-wire circuit as a modulation signal thereto which is transmitted to said second circuit, upon receipt of which said second circuit switches in a circuit for demodulating said signal.
Claim 8
Independent Claim
138 words
A method of interconnecting a first and a second 4-wire circuit through a 2-wire interconnecting circuit in which at least the first of said 4-wire circuits is equipped with an adapter for transmitting a local carrier through said 2-wire circuit to said second 4-wire circuit, said method comprising: upon completion of said interconnection, the transmission from said second to said first 4-wire circuit of a first control signal if said second circuit is equipped with such an adapter, and upon receipt and detection of said first control signal by said first circuit, said first circuit switches in its said local carrier and applies the signals received on the first 4-wire circuit as a modulation signal thereto which is transmitted to said second circuit, upon receipt of which said second circuit switches in a circuit for demodulating said signal.
Claim 9
Dependent Claim
49 words
A method according to claim 6 wherein said first circuit upon switching in its local carrier, also transmits a second control signal to said second circuit, upon receipt of which second control signal the second circuit switches in a circuit for demodulating the signals received from said first circuit.
Claim 10
Dependent Claim
124 words
An adapter for installation between a 4-wire communication circuit and a 2-wire telephone switching circuit comprising: an outgoing call section for transmitting intelligence signals in the receiving path of said 4-wire communication circuit on a local carrier through said 2-wire telephone switching circuit, an incoming call section for recovering intelligence signals from a local carrier wave transmitted to the sending path of said 4-wire communication circuit from said 2-wire telephone switching circuit, and call mode control circuit means responsive to signals indicative of the direction of a call for connecting said outgoing or incoming call section betweeN said 4-wire communication circuit and said 2-wire telephone switching circuit, respectively, when a call proceeds from or to said 4-wire circuit to or from said 2-wire circuit.
Claim 11
Dependent Claim
124 words
An adapter for installation between a 4-wire communication circuit and a 2-wire telephone switching circuit comprising: an outgoing call section for transmitting intelligence signals in the receiving path of said 4-wire communication circuit on a local carrier through said 2-wire telephone switching circuit, an incoming call section for recovering intelligence signals from a local carrier wave transmitted to the sending path of said 4-wire communication circuit from said 2-wire telephone switching circuit, and call mode control circuit means responsive to signals indicative of the direction of a call for connecting said outgoing or incoming call section betweeN said 4-wire communication circuit and said 2-wire telephone switching circuit, respectively, when a call proceeds from or to said 4-wire circuit to or from said 2-wire circuit.
Claim 12
Dependent Claim
73 words
An adapter as in claim 8 wherein said outgoing call section comprises detecting means associated with the sending path of said 4-wire communication circuit for detecting a first control signal, and modulating means associated with the receiving path of said 4-wire communication circuit and responsive to said detecting means for detecting said first control signal for modulating intelligence signals thereat on a local carrier wave for passage through said 2-wire telephone switching network.
Claim 13
Dependent Claim
42 words
An adapter as in claim 9 wherein said modulating means is coupled in the receiving path by switching circuit means which is arranged to bypass said modulating means in the absence of receipt of said first control signal by said detecting means.
Claim 14
Dependent Claim
29 words
An adapter as in claim 10 wherein said switching circuit means is coupled to said detecting means by a switching control means which is responsive to said detecting means.
Claim 15
Dependent Claim
50 words
An adapter as in claim 11 and further comprising audio detecting means associated with the sending path of said 4-wire communication circuit for detecting a predetermined audio control signal, and a first switch means responsive to said audio detecting means for connecting said detecting means to said switching control means.
Claim 16
Dependent Claim
29 words
An adapter as in claim 12 and further comprising second switch means responsive to said audio detecting means for connecting said switching control means to said switching circuit means.
Claim 17
Dependent Claim
53 words
An adapter as in claim 13 wherein said switching control means is responsive to said call mode control circuit means and is arranged to maintain control over said switching circuit means when said 4-wire circuit is interconnected for 4-wire operation through said 2-wire switching circuit and after said first control signal is terminated.
Claim 18
Dependent Claim
32 words
An adapter as in claim 14 wherein said outgoing call section includes control tone generator means associated with the receiving path of said 4-wire communication circuit for transmitting a second control signal.
Claim 19
Dependent Claim
18 words
An adapter as in claim 15 wherein said last mentioned control tone generator means includes said modulating means.
Claim 20
Dependent Claim
68 words
An adapter as in claim 8 wherein said incoming call section comprises detecting means associated with the sending path of said 4-wire communication circuit for detecting a control signal, and demodulating means associated with said sending path and responsive to said detecting means detecting said control signal for demodulating intelligence signals on a local carrier wave transmitted to said 4-wire communication circuit from said 2-wire telephone switching circuit.
Claim 21
Dependent Claim
41 words
An adapter as in claim 17 wherein said demodulating means is coupled to said sending path by switching circuit means responsive to said detecting means and arranged to bypass said demodulating means in the absence of detection of said control signal.
Claim 22
Dependent Claim
31 words
An adapter as in claim 17 wherein said incoming call section includes tone control generating means associated with the receiving path of said 4-wire communication circuit for transmitting another control signal.
Claim 23
Dependent Claim
30 words
An adapter as in claim 19 wherein said tone control generating means comprises a tone oscillator and a switch means arranged to couple said tone oscillator into the receiving path.
Claim 24
Dependent Claim
29 words
An adapter as in claim 17 wherein said incoming call section comprises generating means for selectively applying an audio tone to the receiving path of said 4-wire communication circuit.
Claim 25
Dependent Claim
38 words
Method according to claim 6 in which said 2-wire circuit consists of a switching device by means of which one of the 4-wire communication circuits can be connected to one of a group of other 4-wire communication circuits.
Claim 26
Dependent Claim
37 words
A method according to claim 6 wherein the first 4-wire circuit is associated with the call-originating end of the overall circuit and the second 4-wire circuit is associated with the call receiving end of the overall circuit.
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) | 1978-11-03 | 1979-05-05 | 1979-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-03 | 1983-05-05 | 1983-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-03 | 1987-05-05 | 1987-11-04 | $7700.00 | Window Closed / Lapsed |