US 5,161,180 AGranted

Call interceptor for emergency systems

OwnerRobert O. Chavousinventor

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Abstract

A device for responsively providing, in cooperative association with the 911 emergency system, the number and location of a telephone, especially a PBX extension telephone, from which such a 911 emergency call originates. A first device is installed between PBXs and the extensions thereof, with the number and location of each extension stored in the device's electronic memory. A second such device is installed at a Public Safety Answering Point. When 911 is dialed from an extension telephone of a PBX equipped with a device of the present invention, even if the extension receiver is still on-hook, the extension is connected over telephone lines to the second device installed at the PSAP. The device at the PSAP then interrogates the device at the PBX which responsively transmits the location of the extension telephone from which the call originated. The device installed at the PSAP relays the location information to at least one computer which informs an operator of the location of the calling phone. The Public Safety Answering Point operator is then able to dispatch assistance to the person placing the emergency call. Provision is made for automatically selecting an alternate route if no interrogating signal is detected.

Claims15

Dependent claims

A device, having a data base of information stored in an internal memory, for use as an adjunct to an existing telephone switching and control system and for responsively providing, to 911 and enhanced 911 emergency systems, selected extension identifying information which includes at least the number and location of an extension telephone of said telephone system from which a call comprised of the three digits 911 originates, said device comprising:

sensing means for sensing an off-hook condition of any of a plurality of extension telephones of said telephone system;
detecting means for detecting dialing signals from said extension telephones of said telephone system, whether or not said extension telephones are in said off-hook condition;
selectable responding means for responding to the pressing of a selected single key of said extension telephones as a designated "Panic Button", alternate means of generating a 911 emergency call, said alternate call generating means being functional without the need for taking said extension telephone off-hook;
identification means for determining whether or to said dialing signals from said extension telephones comprise an emergency 911 call, and whether or not said dialing signals were generated by said selected key of said extension telephones as an alternate, "Panic Button" method for dialing said emergency call;
dial tone processing means for detecting, generating, and suppressing at least one dial tone;
memory access means for selectively retrieving and transmitting selected items from said data base of information in response to a finding by said identification means that said call is a 911 emergency call, and appropriate externally generated interrogation signals;
telephone system conformation means for causing said device to modify selected functions thereof in order to conform to selected functions of said telephone system at which said device is installed, aid selected functions of said telephone system including a need for dialing an access code consisting of at least one digit to access an outside line of said phone system in order to dial 911 and the inability of said telephone system to reroute said 911 calls;
interface means for interfacing with computers, conventional telephones, telephone lines and circuits;
and
automatic rerouting means for automatically dialing alternate destination telephone numbers and automatically selecting alternate telephone lines over which to transmit information in case of apparent failure of initially selected route.

7 more elements

A device having an internal memory for storing selected telephone extension identification information, said device for use as an adjunct to an existing telephone system and for responsively providing said selected telephone extension identifying information to emergency telephone systems, said selected telephone extension identifying information including at least the number and location of an extension telephone of said telephone system from which an emergency call originates, said device comprising:

sensing means for sensing an off-hook condition of any of a plurality of said extension telephones of said telephone system;
extension telephone identifying means for identifying which of said plurality of extension telephones has originated said emergency call;
telephone system conformation means for causing said device to modify selected functions thereof in order to conform to selected functions of said telephone system at which said device is installed;
and
automatic rerouting means for automatically dialing alternate destination telephone numbers and automatically selecting alternate telephone lines over which to transmit information.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 07/600,433Filed 19 Oct 1990
Granted: 3 Nov 1992
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

H04Q 3/625
For connecting to private branch exchanges: arrangements in the private branch exchange
H04M 3/5116
Centralised call answering arrangements requiring operator intervention , e.g. call or contact centers for telemarketing: for emergency applications
H04M 3/42314
Systems providing special services or facilities to subscribers: in private branch exchanges
H04M 2242/30
Special services or facilities: determination of the location of a subscriber