US4819261A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Public telephone set
Assignee: Tamura Electric Works Ltd
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Filing: 1988-06-21
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Granted: 1989-04-04
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Expires: 2008-06-21
Abstract
Abstract A public telephone set includes a communication enabling unit, a signal detector, a timer, and a CPU. The communication enabling unit enables incoming communication upon formation of a DC loop based on an incoming call. The signal detector detects a protocol signal from a maintenance center or a service center via the office line. The timer is started upon formation of the DC loop. The CPU instructs to send out alarm information to the maintenance or the service center via the office line when the signal detector generates a detection output during an operation of the timer.
Inventors
- 👤 Yoshiaki Takeda
- 👤 Kazuo Asada
- 👤 Shigehiro Eda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:59
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/24; H04M17/00; H04M17/02; H04M17/023
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
136 words
A public telephone set having an alarm information transmission function for performing a self-diagnosis for predetermined test positions upon detection of a ringing signal from an office line and automatically forming a DC loop, for transmitting a self-diagnostic result in a predetermined form of a signal, and for releasing the DC loop, comprising: communication enabling means for enabling incoming communication upon formation of the DC loop based on the incoming call; signal detecting means for detecting a protocol signal from a maintenance center or a service center via the office line; timer means started upon formation of the DC loop; and control means for sending out alarm information to said maintenance center or said service center via the office line when said signal detecting means generates a detection output during an operation of said timer means.
Claim 2
Dependent Claim
136 words
A public telephone set having an alarm information transmission function for performing a self-diagnosis for predetermined test positions upon detection of a ringing signal from an office line and automatically forming a DC loop, for transmitting a self-diagnostic result in a predetermined form of a signal, and for releasing the DC loop, comprising: communication enabling means for enabling incoming communication upon formation of the DC loop based on the incoming call; signal detecting means for detecting a protocol signal from a maintenance center or a service center via the office line; timer means started upon formation of the DC loop; and control means for sending out alarm information to said maintenance center or said service center via the office line when said signal detecting means generates a detection output during an operation of said timer means.
Claim 3
Dependent Claim
29 words
A set according to claim 1, further comprising means for sending out the protocol signal having a specific frequency to the office line upon formation of the DC loop.
Claim 4
Dependent Claim
41 words
A set according to claim 1, wherein said control means sends out collection data and/or maintenance data as the alarm information in accordance with a type of protocol signal received from the office line and detected by said signal detecting means.
Claim 5
Dependent Claim
21 words
A set according to claim 3, wherein said control means changes preset data in accordance with the type of protocol signal.
Claim 6
Dependent Claim
66 words
A set according to claim 1, further comprising hook state determining means for determining a hook state on the basis of a time-up output from said timer means, and wherein said control means continues the incoming communication when said hook state determining means determines an off-hook state, and releases the office line from the telephone set when said hook state determining means determines an on-hook state.
Claim 7
Dependent Claim
28 words
A set according to claim 1, wherein said control means sends out fault data and an address data assigned inherently to the telephone set as the alarm information.
Claim 8
Dependent Claim
47 words
A set according to claim 1, further comprising a dialing memory, and wherein said control means sets the alarm information in said dialing memory and sends out the alarm information to the office line in accordance with a DTMF (dual-tone multifrequency) signal based on the alarm information.
Claim 9
Dependent Claim
112 words
A public telephone set having an alarm information transmission function for performing a self-diagnosis for predetermined test positions upon detection of a ringing signal from an office line and automatically forming a DC loop, for transmitting a self-diagnostic result in a predetermined form of a signal, and for releasing the DC loop, comprising: hook state determining means for determining a hook state upon formation of the DC loop in response to an incoming call; and control means for allowing incoming communication when said hook state determining means determines an off-hook state and for sending out the alarm information to the office line when said hook state determining means determines an on-hook state.
Claim 10
Dependent Claim
112 words
A public telephone set having an alarm information transmission function for performing a self-diagnosis for predetermined test positions upon detection of a ringing signal from an office line and automatically forming a DC loop, for transmitting a self-diagnostic result in a predetermined form of a signal, and for releasing the DC loop, comprising: hook state determining means for determining a hook state upon formation of the DC loop in response to an incoming call; and control means for allowing incoming communication when said hook state determining means determines an off-hook state and for sending out the alarm information to the office line when said hook state determining means determines an on-hook state.
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) | 1992-04-03 | 1992-10-03 | 1993-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-03 | 1996-10-03 | 1997-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-03 | 2000-10-03 | 2001-04-04 | $7700.00 | Window Closed / Lapsed |