US3978294A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Return answer-supervisory circuit
Assignee: AT&T Inc
•
Filing: 1975-06-16
•
Granted: 1976-08-31
•
Expires: 1995-06-16
Abstract
Abstract A PBX system is disclosed having a return answer supervisory circuit in a local PBX for automatically detecting and extending an answer indication from a called station located in a distant PBX to an attendant's console in the local PBX on tie trunk calls between the local and distant PBXs. The disclosed system is an improvement in the art in that it does not require major modification to existing equipment for returning the answer indication to the attendant's console.
Inventors
- 👤 Albert David Limiero
- 👤 Edwin Walter Lipien
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:10
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/58; H04Q3/62; H04Q3/625
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
168 words
In a telephone switching system having a local PBX, a distant PBX, tie trunks interconnecting said local PBX with said distant PBX, an attendant's console having a plurality of lamps at said local PBX, a matrix type switching network in said local PBX, tie trunk circuitry connected to one side of said network and attendant console control circuitry connected to another side of said network, means for extending a call over one of said tie trunks from said local PBX to a called station in said distant PBX, said local PBX further having a return answer supervisory circuit comprising: means responsive to said extension for signaling one of said lamps on said attendant's console in a first unique code, means responsive to the answering of said call by said called station for transmitting an attendant lamp control signal from said tie trunk circuit through said network to said attendant console control circuitry, and means responsible to said transmitted signal for signaling said lamp in a second unique code.
Claim 2
Dependent Claim
168 words
In a telephone switching system having a local PBX, a distant PBX, tie trunks interconnecting said local PBX with said distant PBX, an attendant's console having a plurality of lamps at said local PBX, a matrix type switching network in said local PBX, tie trunk circuitry connected to one side of said network and attendant console control circuitry connected to another side of said network, means for extending a call over one of said tie trunks from said local PBX to a called station in said distant PBX, said local PBX further having a return answer supervisory circuit comprising: means responsive to said extension for signaling one of said lamps on said attendant's console in a first unique code, means responsive to the answering of said call by said called station for transmitting an attendant lamp control signal from said tie trunk circuit through said network to said attendant console control circuitry, and means responsible to said transmitted signal for signaling said lamp in a second unique code.
Claim 3
Dependent Claim
99 words
The system of claim 1: in which said means for signaling said lamp in a first unique code comprises a relay having make contacts and break contacts and a power source for delivering power according to said first unique code through said break contacts to said lamp; and in which said means for signaling said lamp in a second unique code comprises a power source for delivering power according to said second unique code through said make contacts to said lamp when said relay is operated, said relay being operated when said called station in said distant PBX answers.
Claim 4
Dependent Claim
36 words
The system of claim 1 in which said tie trunk comprises tip and ring leads and said answer condition is a reversal of battery polarity on said tip and ring leads when said called station answers.
Claim 5
Dependent Claim
90 words
The system of claim 3: in which said means for signaling said lamp in a first unique code comprises a relay having make contacts and break contacts and an intermittent power source for delivering intermittent power through said break contacts to said lamp when said relay is released; and in which said means for signaling said lamp in a second unique code comprises a direct current power source for delivering direct current power through said make contacts when said relay is operated in response to said battery polarity reversal condition.
Claim 6
Dependent Claim
202 words
In a telephone switching system having a local PBX, a distant PBX, tie trunks interconnecting said local PBX with said distant PBX, said local PBX having an attendant's console with a plurality of lamps, central office trunk circuits, a switching network, and an interface circuit, said distant PBX having a plurality of stations, means in said local PBX for detecting the receipt of a call appearing on one of said central office trunk circuits and requiring access to a called one of said stations in said distant PBX, means including said attendant's console for establishing a path including a sleeve lead path from said one central office trunk circuit through said network to said interface circuit, and said local PBX further having a return answer supervisory circuit comprising: means in said one central office trunk circuit responsive to the establishment of said sleeve lead path for signaling one of said lamps in said attendant's console in a first unique code, means in said interface circuit interconnected with the called station in said distant PBX over said tie trunk circuit for detecting when said called station answers, and means responsive to said answer detection for signaling said lamp in a second unique code.
Claim 7
Dependent Claim
202 words
In a telephone switching system having a local PBX, a distant PBX, tie trunks interconnecting said local PBX with said distant PBX, said local PBX having an attendant's console with a plurality of lamps, central office trunk circuits, a switching network, and an interface circuit, said distant PBX having a plurality of stations, means in said local PBX for detecting the receipt of a call appearing on one of said central office trunk circuits and requiring access to a called one of said stations in said distant PBX, means including said attendant's console for establishing a path including a sleeve lead path from said one central office trunk circuit through said network to said interface circuit, and said local PBX further having a return answer supervisory circuit comprising: means in said one central office trunk circuit responsive to the establishment of said sleeve lead path for signaling one of said lamps in said attendant's console in a first unique code, means in said interface circuit interconnected with the called station in said distant PBX over said tie trunk circuit for detecting when said called station answers, and means responsive to said answer detection for signaling said lamp in a second unique code.
Claim 8
Dependent Claim
81 words
The system of claim 5 in which said means for signaling comprises: a relay having make contacts and break contacts, means responsive to said answer detection for operating said relay, a first power source for delivering power according to said first unique code through said break contacts to said lamp when said relay is released, and a second power source for delivering power according to said second unique code through said make contacts to said lamp when said relay is operated.
Claim 9
Dependent Claim
189 words
A switching system comprising: a local PBX, a distant PBX having a plurality of stations, a tie trunk interconnecting said PBXs, a tie trunk circuit connected to said tie trunk at said local PBX, an attendant console at said local PBX, a central office connected to said local PBX via a central office trunk circuit, a switching network in said local PBX, means in said local PBX for detecting the receipt by said central office trunk circuit of a call from said central office requiring a connection to a called station at said distant PBX, means including said attendant console for establishing a network path between said central office trunk circuit and said tie trunk circuit, means effective upon said path establishment for extending said call over said tie trunk to said distant PBX, means in said local PBX responsive to the establishment of said network path for displaying a first signal at said attendant console, means in said local PBX for detecting an off hook state of the called station at distant PBX, and means responsive to said detection for displaying a second signal at said attendant console.
Claim 10
Dependent Claim
189 words
A switching system comprising: a local PBX, a distant PBX having a plurality of stations, a tie trunk interconnecting said PBXs, a tie trunk circuit connected to said tie trunk at said local PBX, an attendant console at said local PBX, a central office connected to said local PBX via a central office trunk circuit, a switching network in said local PBX, means in said local PBX for detecting the receipt by said central office trunk circuit of a call from said central office requiring a connection to a called station at said distant PBX, means including said attendant console for establishing a network path between said central office trunk circuit and said tie trunk circuit, means effective upon said path establishment for extending said call over said tie trunk to said distant PBX, means in said local PBX responsive to the establishment of said network path for displaying a first signal at said attendant console, means in said local PBX for detecting an off hook state of the called station at distant PBX, and means responsive to said detection for displaying a second signal at said attendant console.
Claim 11
Dependent Claim
227 words
In a PBX having central office trunk circuits, interface tie trunk circuits, a switching network, common control equipment, and an attendant's console having a plurality of lamps, means including said common control equipment and said attendant's console effective upon the receipt of an incoming call by one of said central office trunk circuits for establishing a network connection from said one central office trunk circuit to an idle one of said interface tie trunk circuits, said one interface tie trunk circuit being interconnected with a called station located in a distant PBX in response to said network connection, means in said one central office trunk circuit for signaling one of said lamps in a first unique code upon the establishment of said network connection, and means in said interface tie trunk circuit responsive to an answer signal from said called station for maintaining the tie trunk connection to said called station, and improvement comprising: first means responsive to said network connection for inhibiting the provision of a second unique code signal by said signaling means to said lamp, second means responsive to said network connection for signaling said lamp in a first unique code, and means interconnected with said first means responsive to said tie trunk maintenance for enabling said signaling means to signal said lamp in said second unique code and for inhibiting said second means.
Claim 12
Dependent Claim
227 words
In a PBX having central office trunk circuits, interface tie trunk circuits, a switching network, common control equipment, and an attendant's console having a plurality of lamps, means including said common control equipment and said attendant's console effective upon the receipt of an incoming call by one of said central office trunk circuits for establishing a network connection from said one central office trunk circuit to an idle one of said interface tie trunk circuits, said one interface tie trunk circuit being interconnected with a called station located in a distant PBX in response to said network connection, means in said one central office trunk circuit for signaling one of said lamps in a first unique code upon the establishment of said network connection, and means in said interface tie trunk circuit responsive to an answer signal from said called station for maintaining the tie trunk connection to said called station, and improvement comprising: first means responsive to said network connection for inhibiting the provision of a second unique code signal by said signaling means to said lamp, second means responsive to said network connection for signaling said lamp in a first unique code, and means interconnected with said first means responsive to said tie trunk maintenance for enabling said signaling means to signal said lamp in said second unique code and for inhibiting said second means.
Claim 13
Dependent Claim
72 words
The system of claim 8: wherein said signaling means for signaling said lamp in said second unique code comprises a relay having make contacts and a second power source for delivering power according to said second unique code through said make contacts to said lamp when said relay is operated; and wherein said inhibiting means comprises means responsive to said network connection for shunting said relay so that said relay remains released.
Claim 14
Dependent Claim
41 words
The system of claim 9 wherein said second means comprises: break contacts in said relay, and a second power source for delivering power according to said second unique code through said break contacts to said lamp when said relay is released.
Claim 15
Dependent Claim
34 words
The system of claim 10 wherein said enabling means comprises: a current source, and means responsive to said tie trunk maintenance for connecting said current source to said relay so that said relay operates.
Claim 16
Independent Claim
248 words
A method for providing return answer supervision in a PBX having central office trunk circuits, a network, interface tie trunk circuits, common control equipment, and an attendant's console with a plurality of lamps, said common control equipment being controlled by said attendant's console upon the receipt of a call on one of said central office trunk circuits for establishing a connection in said network from said one central office trunk circuit to an idle one of said interface tie trunk circuits, said one interface tie trunk being interconnected with a called station located in a distant PBX in response to said network connection, means in said one central office trunk circuit for signaling one of said lamps in a first unique code upon the establishment of said network connection, and means in said interface tie trunk circuit responsive to an answer signal from said called station for maintaining the tie trunk connection to said called station, said method comprising the steps of: inhibiting the provision of a second unique code signal by said signaling means to said one lamp in response to said network connection, signaling said one lamp according to a first unique code in response to said network connection, inhibiting the provision of the first unique code signal to said one lamp in response to said tie trunk maintenance, an enabling the provision of the second unique code signal by said signaling means to said one lamp in response to the inhibiting of said first signal.
Claim 17
Independent Claim
248 words
A method for providing return answer supervision in a PBX having central office trunk circuits, a network, interface tie trunk circuits, common control equipment, and an attendant's console with a plurality of lamps, said common control equipment being controlled by said attendant's console upon the receipt of a call on one of said central office trunk circuits for establishing a connection in said network from said one central office trunk circuit to an idle one of said interface tie trunk circuits, said one interface tie trunk being interconnected with a called station located in a distant PBX in response to said network connection, means in said one central office trunk circuit for signaling one of said lamps in a first unique code upon the establishment of said network connection, and means in said interface tie trunk circuit responsive to an answer signal from said called station for maintaining the tie trunk connection to said called station, said method comprising the steps of: inhibiting the provision of a second unique code signal by said signaling means to said one lamp in response to said network connection, signaling said one lamp according to a first unique code in response to said network connection, inhibiting the provision of the first unique code signal to said one lamp in response to said tie trunk maintenance, an enabling the provision of the second unique code signal by said signaling means to said one lamp in response to the inhibiting of said first signal.
Claim 18
Independent Claim
206 words
The method of operating a PBX having central office trunk circuits, a switching network, interface tie trunk circuits, common control equipment, and an attendant's console with a plurality of lamps, said method comprising the steps of: detecting the receipt by one of said central office trunk circuits of a call that requires a connection to a called station in a distant PBX, establishing under control of said attendant's console a network connection from said one central office trunk circuit to an idle one of said interface tie trunk circuits, shunting the coil of a relay in response to said network connection so that said relay is prevented from operating, said relay being provided for signaling one of said lamps through make contacts of said relay in a second unique code upon the answering of said call at said distant PBX, signaling said one lamp according to a first unique code through break contacts of said relay in response to said network connection, supplying current to the coil of said relay in response to an answer signal from said distant PBX on said one interface tie trunk circuit so that said relay operates, and signaling said one lamp according to said second code when said relay operates.
Claim 19
Independent Claim
206 words
The method of operating a PBX having central office trunk circuits, a switching network, interface tie trunk circuits, common control equipment, and an attendant's console with a plurality of lamps, said method comprising the steps of: detecting the receipt by one of said central office trunk circuits of a call that requires a connection to a called station in a distant PBX, establishing under control of said attendant's console a network connection from said one central office trunk circuit to an idle one of said interface tie trunk circuits, shunting the coil of a relay in response to said network connection so that said relay is prevented from operating, said relay being provided for signaling one of said lamps through make contacts of said relay in a second unique code upon the answering of said call at said distant PBX, signaling said one lamp according to a first unique code through break contacts of said relay in response to said network connection, supplying current to the coil of said relay in response to an answer signal from said distant PBX on said one interface tie trunk circuit so that said relay operates, and signaling said one lamp according to said second code when said relay operates.
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) | 1979-08-31 | 1980-03-01 | 1980-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-31 | 1984-03-01 | 1984-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-31 | 1988-03-01 | 1988-08-31 | $7700.00 | Window Closed / Lapsed |