US3833897A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Intrusion detection system and method using an electret cable
Assignee: GTE Sylvania Inc
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Filing: 1973-03-13
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Granted: 1974-09-03
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Expires: 1993-03-13
Abstract
Abstract An intrusion detection system comprises a fence mounted coaxial electret cable connected to remote signal processing apparatus which includes both automatic alarm circuits and a loudspeaker, the latter producing sounds generated by audio frequency signals propagating on the cable. The automatic alarm circuit responds to cable signals that meet predetermined criteria for bandpass, amplitude and duration to indicate a suspected intrusion; the loudspeaker reproduces sounds caused by the condition which produces the alarm and permits the operator to aurally determine the nature of the condition for verifying in real time its valid or spurious character. The signals on the cable may be manually or automatically switched to the loudspeaker or may be continuously connected to it as required or desired.
Inventors
- 👤 M Laymon
- 👤 V Pazemenas
- 👤 R Bell
- 👤 J Dinger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:53
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/02; G08B13/12; G08B13/122; G08B13/16; G08B13/1654; G08B13/169
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
130 words
A system for detecting and identifying a source of mechanical vibrations in a solid body comprising a coaxial electret cable, means for mechanically externally coupling to said cable the mechanical vibrations produced in said body by said source whereby electrical signals are generated by said cable, said signals having a frequency in the audio range, an alarm device, a signal processor electrically connected to said cable and having a first output connected to said device and a second output comprising said audio frequency signals, said processor being responsive to certain of said electrical signals having predetermined characteristics for producing said first output for automatically energizing said alarm device, and transducer means electrically connectable to said second output and responsive to said audio frequency signals for converting same into sound waves.
Claim 2
Independent Claim
130 words
A system for detecting and identifying a source of mechanical vibrations in a solid body comprising a coaxial electret cable, means for mechanically externally coupling to said cable the mechanical vibrations produced in said body by said source whereby electrical signals are generated by said cable, said signals having a frequency in the audio range, an alarm device, a signal processor electrically connected to said cable and having a first output connected to said device and a second output comprising said audio frequency signals, said processor being responsive to certain of said electrical signals having predetermined characteristics for producing said first output for automatically energizing said alarm device, and transducer means electrically connectable to said second output and responsive to said audio frequency signals for converting same into sound waves.
Claim 3
Dependent Claim
37 words
The system according to claim 1 with automatic switch means connecting to said transducer means said second output of the processor in response to the energizing of said alarm device by the first output from said processor.
Claim 4
Independent Claim
107 words
The method of detecting targets traversing an area protected by a fence consisting of the steps of tightly mechanically coupling a coaxial electret cable to the body of the fence and causing vibrations produced on the fence by a target to be coupled to said cable whereby electrical signals are generated by said cable, automatically actuating an alarm device solely in response to certain of said electrical signals having parameters characteristic of signals generated by the target, and energizing loudspeaker means with all of said electrical signals and aurally verifying the nature of the source of said vibrations to determine whether the alarm is true or false.
Claim 5
Independent Claim
107 words
The method of detecting targets traversing an area protected by a fence consisting of the steps of tightly mechanically coupling a coaxial electret cable to the body of the fence and causing vibrations produced on the fence by a target to be coupled to said cable whereby electrical signals are generated by said cable, automatically actuating an alarm device solely in response to certain of said electrical signals having parameters characteristic of signals generated by the target, and energizing loudspeaker means with all of said electrical signals and aurally verifying the nature of the source of said vibrations to determine whether the alarm is true or false.
Claim 6
Dependent Claim
19 words
The method according to claim 3 in which said loudspeaker means is energized after actuation of the alarm device.
Claim 7
Dependent Claim
22 words
The method according to claim 3 in which energization of said loudspeaker means is independent of the actuation of the alarm device.
Claim 8
Dependent Claim
33 words
The method according to claim 5 in which said energization of the loudspeaker means is automatic after actuation of the alarm device and is responsive to all electrical signals generated by said cable.
Claim 9
Independent Claim
57 words
The method of detecting intrusions of an area protected by a coaxial electret cable tightly coupled to a solId body consisting of converting into sound waves electrical signals generated on said cable by vibrations transferred to the cable from the body whereby an operator is enabled to aurally determine the nature of the condition producing said vibrations.
Claim 10
Independent Claim
57 words
The method of detecting intrusions of an area protected by a coaxial electret cable tightly coupled to a solId body consisting of converting into sound waves electrical signals generated on said cable by vibrations transferred to the cable from the body whereby an operator is enabled to aurally determine the nature of the condition producing said vibrations.
Claim 11
Dependent Claim
70 words
In combination, a solid body capable of transmitting mechanical vibrations produced by a condition to be monitored, a coaxial electret cable, means for mechanically coupling said cable to said body whereby said vibrations cause said cable to generate an electrical signal, and means responsive to said electrical signal for indicating the character of the condition being monitored and comprising transducer means for converting signals having audio frequencies into sound waves.
Claim 12
Dependent Claim
70 words
In combination, a solid body capable of transmitting mechanical vibrations produced by a condition to be monitored, a coaxial electret cable, means for mechanically coupling said cable to said body whereby said vibrations cause said cable to generate an electrical signal, and means responsive to said electrical signal for indicating the character of the condition being monitored and comprising transducer means for converting signals having audio frequencies into sound waves.
References Cited (Backward Citations)
US2787784A
Cited
US3437759A
Cited
US3475751A
Cited
US3553669A
Cited
US3763482A
Cited
US3750127A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-02 | 1978-03-04 | 1978-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-02 | 1982-03-04 | 1982-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-02 | 1986-03-04 | 1986-09-03 | $7700.00 | Window Closed / Lapsed |