US4408102A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Two-wire exchange telephone system
Assignee: Individual
•
Filing: 1981-04-27
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Granted: 1983-10-04
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Expires: 2001-04-27
Abstract
Abstract Two wire phone exchange system which provides signalling, intercom and paging functions. The system monitors and detects either a dual tone multi-frequency tone or a single tone generated on the line at the local telephone, activates a relay and places a calling party on hold and connects music to the incoming line. A party on hold is reconnected to the answering telephone by depressing a tone signal generating key button. There is an audible warning tone reminder for calls placed on hold which are not picked up after some desired time. The system also provides in-house intercom and paging functions and a release from these functions. When several local telephone instruments are connected on the same line, this system allows the recipient of a call to receive the call at any of the telephones by depressing a tone generating key button.
Inventors
- 👤 Steven B. Lumpkin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:21
CPC Classifications
H; H04; H04M; H04M9/00; H04M9/02
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
150 words
A two wire telephone system, comprising: first terminating means for connection to an incoming central office line; second terminating means for connection to a local telephone instrument; a DTMF timer circuit; phone line switch means for selectively connecting said first and second terminating means; means responsive to a preselected signal tone of a first preselected duration from said telephone instrument for actuating said DTMF timer circuit; means responsive to a first value in said DTMF timer circuit for actuating said switching means to disconnect said first and second terminating means from one another and connect said first terminating means to a conductive holding path and to a source of music signals; and means responsive to said preselected signal tone of a first preselected duration from said local telephone instrument for disconnecting said first terminating means from said holding path and music signals and connecting it to said second terminating means.
Claim 2
Dependent Claim
150 words
A two wire telephone system, comprising: first terminating means for connection to an incoming central office line; second terminating means for connection to a local telephone instrument; a DTMF timer circuit; phone line switch means for selectively connecting said first and second terminating means; means responsive to a preselected signal tone of a first preselected duration from said telephone instrument for actuating said DTMF timer circuit; means responsive to a first value in said DTMF timer circuit for actuating said switching means to disconnect said first and second terminating means from one another and connect said first terminating means to a conductive holding path and to a source of music signals; and means responsive to said preselected signal tone of a first preselected duration from said local telephone instrument for disconnecting said first terminating means from said holding path and music signals and connecting it to said second terminating means.
Claim 3
Dependent Claim
255 words
A two wire exchange telephone system, comprising: first terminating means for connection to an incoming central office line; second terminating means for connection to a local telephone instrument; a DTMF timer curcuit; phone line switch means for selectively connecting said first and second terminating means; means responsive to a preselected signal tone of a first preselected duration from said telephone instrument for actuating said DTMF timer circuit; a page control circuit; means responsive to a first value in said DTMF timer circuit for actuating said switch means to disconnect said first and second terminating means from one another and connect said first terminating means to a conductive holding path and to a source of music signals; means responsive to actuation of said phone line switch means and an off hook condition of said local telephone instrument for actuating said page control circuit; means responsive to a signal from page control circuit for placing a page tone in said local telephone instrument; means responsive to a second signal from page control circuit for interrupting said page tone and connecting said local telephone instrument to a speaker system for paging; means responsive to a third signal from page control circuit for disconnecting said local telephone instrument from said speaker system and inhibiting operation of said page control circuit; and means responsive to said preselected signal tone of a first preselected duration from said local telephone instrument for disconnecting said first terminating means from said holding path and music signals and connecting it to said second terminating means.
Claim 4
Dependent Claim
255 words
A two wire exchange telephone system, comprising: first terminating means for connection to an incoming central office line; second terminating means for connection to a local telephone instrument; a DTMF timer curcuit; phone line switch means for selectively connecting said first and second terminating means; means responsive to a preselected signal tone of a first preselected duration from said telephone instrument for actuating said DTMF timer circuit; a page control circuit; means responsive to a first value in said DTMF timer circuit for actuating said switch means to disconnect said first and second terminating means from one another and connect said first terminating means to a conductive holding path and to a source of music signals; means responsive to actuation of said phone line switch means and an off hook condition of said local telephone instrument for actuating said page control circuit; means responsive to a signal from page control circuit for placing a page tone in said local telephone instrument; means responsive to a second signal from page control circuit for interrupting said page tone and connecting said local telephone instrument to a speaker system for paging; means responsive to a third signal from page control circuit for disconnecting said local telephone instrument from said speaker system and inhibiting operation of said page control circuit; and means responsive to said preselected signal tone of a first preselected duration from said local telephone instrument for disconnecting said first terminating means from said holding path and music signals and connecting it to said second terminating means.
Claim 5
Dependent Claim
44 words
A two wire exchange telephone system as set forth in claim 2 which also includes: means responsive to an actuated phone line switch means and a brief depression of the switch hook of the local telephone instrument for reactuation of said second timing means.
Claim 6
Dependent Claim
57 words
A two wire exchange telephone system as set forth in claim 2 which also includes: a hold timer circuit; means responsive to operation of said phone line switch for actuating said hold timer circuit; and means responsive to operation of said hold timer for applying a hold warning tone to both said first and second terminating means.
Claim 7
Dependent Claim
56 words
A two wire exchange telephone system as set forth in claim 2 which also includes: means responsive to a preselected signal tone of a second preselected duration from said telephone instrument for interrupting the connection between said fist terminating means and said current holding path to present an unoccupied line condition back to the central office.
Claim 8
Dependent Claim
38 words
A two wire exchange telephone system as set forth in claim 5 which also includes: means connected to said first terminating means and responsive to a.c. ringing current for applying an indicating tone to said second terminating means.
Claim 9
Independent Claim
238 words
A method for switching a two wire exchange system including a selectively connectable incoming central office line and a local telephone instrument, said method comprising: providing a DTMF timer circuit; actuating said DTMF timer circuit in response to a preselected signal tone of a first preselected duration from said local telephone instrument; disconnecting said central office line and said local telephone instrument and reconnecting said central office line to a conductive holding path and a source of music signals in response said DTMF timing means reaching a first value; providing a page control circuit; actuating said page control circuit in response to disconnection of said central office line and said local telephone instrument and the presence of an off hook condition in said local telephone instrument; operating a page tone in said local telephone instrument in response to said page control circuit generating said first signal; interrupting the page tone and connecting the local telephone instrument to a speaker system for paging in response to said page control circuit generating a second signal; disconnecting the local telephone instrument from said speaker system and inhibiting operation of said page control circuit in response to said page control circuit generating third signal; and disconnecting said central office line from said holding path and music signals and connecting it to said local telephone instrument in response to said preselected signal tone of a first preselected duration from said local telephone instrument.
Claim 10
Independent Claim
238 words
A method for switching a two wire exchange system including a selectively connectable incoming central office line and a local telephone instrument, said method comprising: providing a DTMF timer circuit; actuating said DTMF timer circuit in response to a preselected signal tone of a first preselected duration from said local telephone instrument; disconnecting said central office line and said local telephone instrument and reconnecting said central office line to a conductive holding path and a source of music signals in response said DTMF timing means reaching a first value; providing a page control circuit; actuating said page control circuit in response to disconnection of said central office line and said local telephone instrument and the presence of an off hook condition in said local telephone instrument; operating a page tone in said local telephone instrument in response to said page control circuit generating said first signal; interrupting the page tone and connecting the local telephone instrument to a speaker system for paging in response to said page control circuit generating a second signal; disconnecting the local telephone instrument from said speaker system and inhibiting operation of said page control circuit in response to said page control circuit generating third signal; and disconnecting said central office line from said holding path and music signals and connecting it to said local telephone instrument in response to said preselected signal tone of a first preselected duration from said local telephone instrument.
Claim 11
Dependent Claim
58 words
A method of switching a two wire exchange system as set forth in claim 7 wherein the method also includes the step of: reactuating said page control circuit in response to a state of disconnection between said central office line and said local telephone instrument and a brief depression of the switch hook of said local telephone instrument.
Claim 12
Dependent Claim
88 words
A method of switching a two wire exchange system as set forth in claim 7 wherein the method also includes the steps of: providing a hold timer circuit; actuating said hold timer circuit in response to disconnection of said central office line and said local telephone instrument and reconnection of said central office line to a conductive holding path and a music source; and applying a hold warning tone to said local P.A. input and telephone instrument in response to said hold timing circuit reaching a first alue.
Claim 13
Dependent Claim
63 words
A method of switching a two wire exchange system as set forth in claim 7 wherein the method also includes the step of: interrupting the connection between said central office line and said current holding path in response to a preselected signalling tone of a second preselected duration from said telephone instrument to present an unoccupied line condition back to the central office.
Claim 14
Dependent Claim
47 words
A method of switching a two wire exchange system as set forth in claim 7 wherein the method also includes the step of: applying an indicating tone to said local telephone instrument and to P.A. input in response to a.c. ringing current on said central office line.
References Cited (Backward Citations)
US3806665A
Cited
US4031329A
Cited
US4056695A
Cited
US4100375A
Cited
US4107473A
Cited
US4194093A
Cited
US4377726A
Cited
US4311880A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-10-03 | 1987-04-04 | 1987-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-03 | 1991-04-04 | 1991-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-03 | 1995-04-04 | 1995-10-04 | $7700.00 | Window Closed / Lapsed |