US4737981A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Telephone control device
Assignee: GRH ELECTRONICS Inc
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Filing: 1987-03-06
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Granted: 1988-04-12
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Expires: 2007-03-06
Abstract
Abstract A combination of fixed frequency audio tones and conventional dual tones (as generated by a DTMF telephone set), are used in the autoline control circuit of the invention. All tones are generated by the DTMF telephone set to systematically provide functions available to the subscriber without need for quad conductors in the in-house telephone line and mechanical disconnects. Low cost integration of the present invention into existing FCC tarriffed DTMF equipment and systems without adverse effects is a paramount requirement as the above-mentioned functions are carried out. Conventional jacks and plugs are used to place the parallel autoline circuit of the invention in parallel with the DTMF telephones and the conventional in-premises line connector.
Inventors
- 👤 Kenneth H. Hoberman
- 👤 Kim J. Kirwan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:33
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/71; H04M1/715; H04M1/26; H04M1/27; H04M1/274; H04M1/2745
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
143 words
A telephone control system comprising: means for connection in parallel with a subscriber's tone-dialing DTMF telephone set connected to a conventional telephone line comprising tip and ring conductors; means for decoding DTMF dual-tones on said telephone line; means for decoding DTMF single tones on said telephone line; an off-hook detector connected to said telephone line to selectively detect off-hook DC current; a parallel load holding circuit connected to said telephone line for selectively providing an off-hook local loop transparent condition; a selectively controlled tone generator connected to said telephone line; and a processor for assimilating data from said means for decoding DTMF dual-tones, said means for decoding DTMF single tones and said off-hook detector, said processor controlling said tone generator, and said holding circuit in response thereto, to provide the functions listed above without affecting said local line switching and tone generating equipment.
Claim 2
Dependent Claim
143 words
A telephone control system comprising: means for connection in parallel with a subscriber's tone-dialing DTMF telephone set connected to a conventional telephone line comprising tip and ring conductors; means for decoding DTMF dual-tones on said telephone line; means for decoding DTMF single tones on said telephone line; an off-hook detector connected to said telephone line to selectively detect off-hook DC current; a parallel load holding circuit connected to said telephone line for selectively providing an off-hook local loop transparent condition; a selectively controlled tone generator connected to said telephone line; and a processor for assimilating data from said means for decoding DTMF dual-tones, said means for decoding DTMF single tones and said off-hook detector, said processor controlling said tone generator, and said holding circuit in response thereto, to provide the functions listed above without affecting said local line switching and tone generating equipment.
Claim 3
Dependent Claim
20 words
The telephone control system of claim 1 wherein memory dialing is provided to all tone-dialing telephones on said telephone line.
Claim 4
Dependent Claim
77 words
The telephone control system of claim 1 wherein said means for decoding single tone detection comprises: a high group/low group filter for providing a high group output signal and a low group output signal; a digital period counter; and means for selectively applying said high group output signal and said low group output signal to said digital period counter; wherein said processor performs an evaluation of the results of said period counter to decode valid single tones.
Claim 5
Dependent Claim
29 words
The telephone control system of claim 1 which provides, for all tone-dialing telephones on said telephone line, automatic redialing of the last telephone number called on said telephone line.
Claim 6
Dependent Claim
45 words
The telephone control system of claim 1 which provides, for all tone-dialing telephones on said telephone line, signal to a user to pick up a telephone at a prearranged time and automatic tone-dialing of a selected telephone number when the user picks up a telephone.
Claim 7
Dependent Claim
20 words
The telephone control system of claim 1 which provides, for all tone-dialing telephones on said telephone line, a "hold" function.
Claim 8
Dependent Claim
20 words
The telephone control system of claim 1 which provides, for all tone-dialing telephones on said telephone line, a "paging" function.
Claim 9
Dependent Claim
20 words
The telephone control system of claim 1 which provides, for all tone-dialing telephones on said telephone line, a "howl" function.
Claim 10
Dependent Claim
24 words
The telephone control system of claim 1 which provides, for all tone-dialing telephones on said telephone line, timing of the length of telephone calls.
Claim 11
Dependent Claim
43 words
The telephone control system of claim 1 which further comprises a remote circuit connected in parallel to said telephone line, said remote circuit including a separate processor circuit for monitoring said telephone line for dual frequency tones and controlling an external signaling device.
Claim 12
Dependent Claim
25 words
The telephone control system of claim 10 wherein said external signaling device operates in response to signal tones associated with callback, paging or hold functions.
Claim 13
Dependent Claim
17 words
The telephone control system of claim 11 wherein said external signaling device is an audio signaling device.
Claim 14
Dependent Claim
22 words
The telephone control system of claim 1 which further comprises an external signaling device operating in response to paging or hold functions.
Claim 15
Dependent Claim
17 words
The telephone control system of claim 13 wherein said external signaling device is an audio signaling device.
References Cited (Backward Citations)
US4459434A
Cited
US4578540A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-04-12 | 1991-10-12 | 1992-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-12 | 1995-10-12 | 1996-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-12 | 1999-10-12 | 2000-04-12 | $7700.00 | Window Closed / Lapsed |