US4759050A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Intelligent toll telephone system and method
Assignee: Protel Inc
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Filing: 1986-12-22
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Granted: 1988-07-19
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Expires: 2006-12-22
Abstract
Abstract A toll telephone coupled to tip and ring conductors of a toll trunk and through which various toll signals flow between a central office and the telephone (such as a coin ground signal to indicate the presence of the coin) has a hook switch with an off-hook condition for instituting the flow of loop current. To allow local, coin-free calls, the telephone has electronic circuitry for applying a simulated coin ground signal to the tip conductor continuously during the off-hook condition to permit coin-free calls to be made from the toll telephone. Additionally, the telephone includes a single relay system for providing an open-loop coin check responsive to a corresponding signal from the central office. The telephone provides a notch filter for discriminating against one of the multiple frequencies of a bong tone, thus allowing the remaining frequency to be detected.
Inventors
- 👤 Regis B. Mellon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 15:32
CPC Classifications
H; H04; H04M; H04M17/00; H04M17/02; H04M17/023
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
123 words
A toll telephone for use in a telephone system with a central office having a toll trunk including tip, ring and ground conductors coupled to said telephone and through which various toll signals flow between said central office and said telephone including a coin ground signal to indicate the presence of a coin, said toll telephone comprising: a hook-switch having an off-hook condition for instituting the flow of loop current through said toll telephone from said tip and ring conductors; and means at said telephone for applying a simulated coin ground signal to said tip conductor continuously during said off-hook condition or momentarily as a result of an open loop coin check to permit coin-free local calls to be made from said telephone.
Claim 2
Dependent Claim
123 words
A toll telephone for use in a telephone system with a central office having a toll trunk including tip, ring and ground conductors coupled to said telephone and through which various toll signals flow between said central office and said telephone including a coin ground signal to indicate the presence of a coin, said toll telephone comprising: a hook-switch having an off-hook condition for instituting the flow of loop current through said toll telephone from said tip and ring conductors; and means at said telephone for applying a simulated coin ground signal to said tip conductor continuously during said off-hook condition or momentarily as a result of an open loop coin check to permit coin-free local calls to be made from said telephone.
Claim 3
Dependent Claim
38 words
The toll telephone recited in claim 1 wherein said means for applying a simulated coin ground signal comprises an electronic simulated inductive circuit means having a relatively low direct current resistance and a relatively high alternating current impedance.
Claim 4
Dependent Claim
33 words
The telephone system recited in claim 1 further comprising a coin escrow relay and means at said toll telephone for sensing coin conditions and operating said escrow relay for coin collection or refund.
Claim 5
Dependent Claim
43 words
The toll telephone recited in claim 3 further comprises means including a single relay switching in either said escrow relay or said simulated inductive circuit means during either the open loop type coin check interval or continously in a continuous ground type system.
Claim 6
Dependent Claim
39 words
The toll telephone recited in claim 1 further comprising: coin totalization means at said telephone; means for deenergizing said telephone following completion of said off-hook condition; and means for latching said coin totalization means during deenergization of said telephone.
Claim 7
Dependent Claim
57 words
The toll telephone recited in claim 1 wherein said central office toll signals include a multiple frequency bong tone and wherein said telephone further comprises means including a notch filter for discriminating against one of said multiple frequencies while the remaining frequency is detected by way of a zero crossing detector means, for detecting said bong tone.
Claim 8
Dependent Claim
81 words
A toll telephone for use in a telephone system with a central office having a toll trunk including tip and ground conductors coupled to said telephone and through which various toll signals flow between said central office and said telephone including a multiple frequency bong tone, and wherein said toll telephone comprises means including a notch filter for discriminating against one of said multiple frequencies and the remaining frequency is detected by a zero crossing technique for detecting said bong tone.
Claim 9
Dependent Claim
81 words
A toll telephone for use in a telephone system with a central office having a toll trunk including tip and ground conductors coupled to said telephone and through which various toll signals flow between said central office and said telephone including a multiple frequency bong tone, and wherein said toll telephone comprises means including a notch filter for discriminating against one of said multiple frequencies and the remaining frequency is detected by a zero crossing technique for detecting said bong tone.
Claim 10
Dependent Claim
81 words
A toll telephone for use in a telephone system with a central office having a toll trunk including tip and ground conductors coupled to said telephone and through which various toll signals flow between said central office and said telephone including an open-loop coin check, said toll telephone comprising means providing ground through an escrow relay on an simulated inductor circuit during the open loop coin check interval or for the duration of the call in a continuous ground type system.
Claim 11
Dependent Claim
81 words
A toll telephone for use in a telephone system with a central office having a toll trunk including tip and ground conductors coupled to said telephone and through which various toll signals flow between said central office and said telephone including an open-loop coin check, said toll telephone comprising means providing ground through an escrow relay on an simulated inductor circuit during the open loop coin check interval or for the duration of the call in a continuous ground type system.
Claim 12
Independent Claim
132 words
A method for operating and completing local calls on a coin telephone without inserting a coin, wherein said telephone is used in a telephone system with a central office having a toll trunk including tip and ring conductors coupled to said telephone and through which various toll signals flow between said central office and said telephone including a coin ground signal to indicate the presence of a coin, said method comprising the steps of: providing a hook switch having an off-hook condition for initiating the flow of loop current through said toll telephone between said tip and ring conductors; and applying a simulated coin ground signal at said telephone to said tip conductor continuously during said off-hook condition to permit coin-free operation of said toll telephone in a continuous ground type system.
Claim 13
Independent Claim
132 words
A method for operating and completing local calls on a coin telephone without inserting a coin, wherein said telephone is used in a telephone system with a central office having a toll trunk including tip and ring conductors coupled to said telephone and through which various toll signals flow between said central office and said telephone including a coin ground signal to indicate the presence of a coin, said method comprising the steps of: providing a hook switch having an off-hook condition for initiating the flow of loop current through said toll telephone between said tip and ring conductors; and applying a simulated coin ground signal at said telephone to said tip conductor continuously during said off-hook condition to permit coin-free operation of said toll telephone in a continuous ground type system.
Claim 14
Dependent Claim
40 words
The method recited in claim 9 further comprising the steps of: providing a coin escrow relay at said toll telephone; and sensing coin conditions at said telephone and operating said escrow relay from said telephone for coin collection or refund.
Claim 15
Dependent Claim
38 words
The method recited in claim 9 further comprising the steps of: providing coin totalization means at said telephone; deenergizing said telephone following completion of said off-hook condition; and latching said coin totalization means during deenergization of said telephone.
References Cited (Backward Citations)
US4139736A
Cited
DE2913388A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-07-19 | 1992-01-18 | 1992-07-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-19 | 1996-01-18 | 1996-07-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-19 | 2000-01-18 | 2000-07-19 | $7700.00 | Window Closed / Lapsed |