US3903373A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Combined operator controlled dial-up conference for PBX
Assignee: Telex Computer Products Inc
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Filing: 1973-04-17
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Granted: 1975-09-02
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Expires: 1993-04-17
Abstract
Abstract A conference circuit for a private automatic branch exchange wherein the conference may be established and controlled either by the operator or by a subscriber on a dial-up basis. Provision is also made for connecting incoming trunk calls into the conference at a selected trunk port. In addition, provision is made for switching control over the conference from the initiating party to the second party when the initiating party releases.
Inventors
- 👤 Klaus Gueldenpfennig
- 👤 Robert F Pedrick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 00:31
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/58; H04Q3/62; H04Q3/625; H04M; H04M3/00; H04M3/42; H04M3/56; H04M2203/00; H04M2203/50; H04M2203/5063
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
320 words
In a private automatic branch exchange including a plurality of subscriber line circuits and at least one operator position circuit, a conference circuit for interconnecting a plurality of subscribers in a common communication comprising an access matrix including a plurality of ports formed by respective transmission pairs, a common bus and switching means for selectively connecting said ports to said common bus; advance control means responsive to the occupied condition of said ports for actuating said switching means to connect non-occupied ports to said common bus in sequential order; core sensing means connected to one of said ports to detect line conditions, said one port being directly connected to said common bus; logic circuit means responsive to said core sensing means detecting a hookflash signal for actUating said advance control means to connect the next non-occupied port in said sequence to said common bus, conference amplifiers associated with each port, said switching means including first switching means associated with each port for selectively connecting that port to said common bus, and second switching means associated with each port for selectively connecting that port to a conference amplifier; said logic circuit means including sequence control means for operating said advance control means to operate a select one of said first switching means and a corresponding one of said second switching means in response to alternate detected hookflash signals, said logic circuit means including a hookflash detection circuit connected to said core sensing means, the output of said hookflash detection circuit being connected to said sequence control means, and wherein a line relay is connected to each of said ports via said second switching means, said logic circuit means including party control means for connecting said hookflash detection circuit to the line relay of only a single designated port other than that to which said core sensing means is connected in response to release of the subscriber from said core sensing means.
Claim 2
Dependent Claim
320 words
In a private automatic branch exchange including a plurality of subscriber line circuits and at least one operator position circuit, a conference circuit for interconnecting a plurality of subscribers in a common communication comprising an access matrix including a plurality of ports formed by respective transmission pairs, a common bus and switching means for selectively connecting said ports to said common bus; advance control means responsive to the occupied condition of said ports for actuating said switching means to connect non-occupied ports to said common bus in sequential order; core sensing means connected to one of said ports to detect line conditions, said one port being directly connected to said common bus; logic circuit means responsive to said core sensing means detecting a hookflash signal for actUating said advance control means to connect the next non-occupied port in said sequence to said common bus, conference amplifiers associated with each port, said switching means including first switching means associated with each port for selectively connecting that port to said common bus, and second switching means associated with each port for selectively connecting that port to a conference amplifier; said logic circuit means including sequence control means for operating said advance control means to operate a select one of said first switching means and a corresponding one of said second switching means in response to alternate detected hookflash signals, said logic circuit means including a hookflash detection circuit connected to said core sensing means, the output of said hookflash detection circuit being connected to said sequence control means, and wherein a line relay is connected to each of said ports via said second switching means, said logic circuit means including party control means for connecting said hookflash detection circuit to the line relay of only a single designated port other than that to which said core sensing means is connected in response to release of the subscriber from said core sensing means.
Claim 3
Dependent Claim
36 words
A conference circuit as defined in claim 1 wherein said operator position circuit is operatively associated with a prescribed one of said ports, each of said ports being connected by a line circuit to said exchange.
Claim 4
Dependent Claim
52 words
A conference circuit as defined in claim 2, including operator control means for connecting said operator position circuit to said sequence control means and means responsive to said operator control means for inhibiting the output of said hookflash detection circuit while said operator position circuit is connected to said sequence control means.
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) | 1978-09-01 | 1979-03-03 | 1979-09-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-01 | 1983-03-03 | 1983-09-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-01 | 1987-03-03 | 1987-09-02 | $7700.00 | Window Closed / Lapsed |