Communications: electrical – Condition responsive indicating system – Specific condition
Reexamination Certificate
2000-12-26
2002-08-06
Tweel, John (Department: 2632)
Communications: electrical
Condition responsive indicating system
Specific condition
C340S654000, C340S656000, C439S638000, C379S033000, C379S035000
Reexamination Certificate
active
06429779
ABSTRACT:
FIELD OF THE INVENTION
This invention relates generally to telephone line monitoring and alarm apparatus, and more specifically to an apparatus for continuously monitoring the status of a telephone line and activating an audio-visual alarm if the telephone line becomes inoperative due to intentional or accidental disruption of telephone service.
BACKGROUND OF THE INVENTION
Telephone service to a subscriber may be disrupted as a result of a malfunction occurring on the utility-provided central office line or on-premise subscriber line. A telephone line may become inoperative due to accidental breakage or shorting, as may occur from inclement weather, or through deliberate action, such as during a burglary in which the on-premise subscriber line is cut to disconnect an alarm system from a central monitoring station or prevent a victim from calling for assistance. Regardless of the cause of the disruption, the telephone subscriber will be without telephone service and will, in general, not be aware that the telephone line is inoperative. It is therefore desirable to have a simple and reliable telephone line monitor and alarm means which functions to continuously monitor the integrity of the telephone line and alert a subscriber by both visual and auditory signals if a disruption in telephone service occurs.
Apparatus designed to assess the status and integrity of a telephone line may be broadly grouped into two principal types: 1. Intermittent use test instruments intended primarily for use by professionals skilled in telephone system maintenance and repair. Equipment of this kind typically includes a variety of display devices such as meters or LED indicators and may be specifically adapted to test for line faults by interconnection to the central office or subscriber segment of the telephone line 2. Continuous line monitoring apparatus intended as on-premise devices which are connected directly to the subscriber segment of the telephone line and provide continuous fault detection and alarm warning if service is disrupted. Both types of apparatus may test for open circuit, line-to-ground faults, the presence of extraneous AC voltage, or abnormal impedance characteristics in either the tip or ring conductors of the telephone line. Moreover, telephone line test and monitoring devices may be based on simple line voltage sensing, impedance measurement by means of current sensing, or extraneous AC voltage fault detection.
In the case of telephone line monitoring apparatus intended for continuous use on the subscriber premises, the primary objective is to alert the subscriber by both visual and auditory means if telephone service is disrupted. Advances in the current art of continuous telephone line monitoring apparatus are needed in order to meet this objective in a reliable, cost-effective and simple manner based on innovative features which also enhance product convenience and manner of use.
It is appreciated that numerous telephone line monitors are known in the art. Examples are U.S. Pat. No. 5,696,810 to Dunn, U.S. Pat. Nos. 5,056,131 and 4,969,179 to Kanare and Rehler, and U.S. Pat. No. 4,969,178 to Chen and Loao.
In U.S. Pat. No. 5,696,810, an apparatus is disclosed for monitoring the integrity of a telephone line and for warning when the line is inoperative. The device comprises a monitoring unit which continuously senses line voltage and generates a control signal which assumes a first value when the line is operational and a second value when the line is inoperative. A battery powered audio alarm is activated when said control signal assumes a second value corresponding to an inoperative line condition. Connection of the device to the telephone line is made by means of a standard telephone cable and plug.
Exemplary continuous telephone line monitors which provide both visual and auditory alarms if the telephone line becomes inoperative may be found in U.S. Pat. Nos. 5,056,131 and 4,969,179. In U.S. Pat. No. 5,056,131, there is provided means for activating a self-flashing light emitting diode and an auditory sounder having alternating loud and soft output in response to a detected low voltage fault condition on the telephone line. The monitoring and alarm circuitry is powered by a battery, or by an AC source with battery back-up. U.S. Pat No. 4,969,179 discloses a continuous telephone line monitor which activates a light emitting diode and auditory sounder if line voltage falls below approximately 6 VDC, corresponding to a short or open circuit fault condition. In both disclosures connection of the device to the telephone line is made in standard fashion by means of a telephone cable and plug.
In U.S. Pat. No. 4,969,178 a multipurpose subscriber telephone line monitor is provided which uses a voltage detecting circuit, a current detecting circuit, two control circuits and a comparator circuit to detect open-circuit, short-circuit, or illegal connection of the subscriber local line. An alarm circuit is employed to generate an audio alarm signal when the telephone line becomes inoperative.
In summary, the prior art has evolved to provide varied and effective means for continuous telephone line monitoring and alarm activation in response to fault conditions having accidental or deliberate origin and which result in a disruption in telephone service to a subscriber. However, simple and reliable means for connecting a telephone line monitor to a standard telephone line, have either not been addressed, or have involved the use of hard-wiring or cable-plug attachments to effect said monitor-telephone line connection. The use of hard-wired connections or cable-plug attachments may be undesirable in many routine consumer applications, however, because of the need for special skills in the case of hard-wiring and the loss of telephone jack access for other telecommunication equipment in the case of cable-plug configurations. Moreover, although the prior art is predominantly based on battery powered or battery back-up operation to activate alarms in the event of telephone service disruption, little or no attention has been given to low battery voltage sensing and audio-visual warning to permit battery replacement in a timely manner in order to ensure on-going product reliability. Finally, the prior art in continuous telephone line monitors has not provided for a simple and effective means to indicate that the device is ON and operational as opposed to connected but in the OFF state, a feature which is of significant importance in view of the intended application.
Therefore, in many continuous telephone line monitoring applications, it is desirable to provide a simple and reliable means for continuously monitoring telephone line status and activating an audio-visual alarm if the telephone line becomes inoperative, comprising direct plug-in connection to a standard telephone wall jack as a self-contained and autonomous unit without interconnecting cables or cable-plug attachments. It is further desirable for said apparatus to provide integral means to permit the uninterrupted use of standard telecommunication equipment, such as telephones, answering machines, or facsimile equipment, with said monitoring and alarm apparatus. Moreover, telephone monitoring and alarm apparatus must incorporate audio-visual low battery indicating means and ON status indicating means to be effective in continuous-use consumer applications.
SUMMARY OF THE INVENTION
It is thus an object of the present invention to provide a telephone line monitor and alarm means capable of continuously monitoring line status and activating an audio-visual alarm if the telephone line becomes inoperative, said means capable of direct plug-in connection to a standard telephone wall jack as a self-contained and autonomous unit without interconnecting cables or cable-plug attachments.
It is a further object of the present invention to provide a dual jack splitter as an integral part of said self-contained and autonomous telephone line monitor and alarm means, in order to permit the uninterrupted use of standard telecommunication e
De Saint-Rome Christian
Deane Brian
Matharu Surjit
Petrillo Gino
Holland & Knight LLP
Tweel John
LandOfFree
Telephone line monitoring and alarm apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Telephone line monitoring and alarm apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Telephone line monitoring and alarm apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2952014