US3836899A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Intrusion detection and locating system
Assignee: GTE Sylvania Inc
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Filing: 1973-09-04
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Granted: 1974-09-17
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Expires: 1993-09-04
Abstract
Abstract A disturbance detection and location system comprises an elongated composite sensor line having a pair of closely spaced coaxial electret cables with known different sensitivities over their lengths and circuits responsive to electrical signals from the cables caused by a disturbance for producing an indication of the disturbance and its location. Such a system is useful for fence-type perimeter intrusion detection where the disturbances to be identified are intruders climbing or cutting the fence. The cables have predetermined different responses to the same mechanical disturbance occurring at the different locations throughout their lengths and measurement of this response difference provides a basis for identifying the location of the disturbance along the monitored line. The cables are electrically connected at one of their adjacent ends to signal processing circuits which correlate the difference in known sensitivitydistance variations of the cables to indicate both the existence of a disturbance (climbing of fence, cutting of fence, etc.) and its location along the cables.
Inventors
- 👤 K Duvall
- 👤 G Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 01:07
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/02; G08B13/12; G08B13/122; H; H10; H10N; H10N30/00; H10N30/60
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
72 words
A detection system comprising a plurality of longitudinally continuous laterally proximate coextensive transducers adapted to produce output electrical signals in response to a mechanical force applied to the transducers, the combined response of said transducers to the same force applied thereto at each of a plurality of longitudinally spaced locations being different, and circuit means responsive to combined output signals from said transducers for indicating the location of applications of said force.
Claim 2
Dependent Claim
72 words
A detection system comprising a plurality of longitudinally continuous laterally proximate coextensive transducers adapted to produce output electrical signals in response to a mechanical force applied to the transducers, the combined response of said transducers to the same force applied thereto at each of a plurality of longitudinally spaced locations being different, and circuit means responsive to combined output signals from said transducers for indicating the location of applications of said force.
Claim 3
Dependent Claim
16 words
THe detection system according to claim 1 in which said transducers are juxtaposed coaxial electret cables.
Claim 4
Dependent Claim
15 words
The detection system according to claim 1 in which said transducers comprise a triaxial cable.
Claim 5
Dependent Claim
87 words
The detection system according to claim 1 in which each of said transducers comprises a plurality of sections in longitudinal series, said transducers being oriented relative to each other so that laterally adjacent sections are coextensive and have substantially equal lengths and constitute sets of sections, the sensitivities of each set of said sections being such that a mechanical force simultaneously applied to each section of one set produces output signals from said transducers which indicate the identity of the set to which said force is applied.
Claim 6
Dependent Claim
45 words
The system according to claim 4 in which said circuit means comprises means for comparing the outputs of said transducers for producing an output representing said identity of the set, and display means responsive to the output of said comparing means for indicating said identification.
Claim 7
Dependent Claim
160 words
An intrusion detection system comprising first and second laterally proximate coaxial electret cables extending along the boundary of an area to be protected, each of said cables having an electret filler with an electrostatic charge of predetermined strength affecting the sensitivity of the cable, at least one of said cables having a sensitivity that is different at longitudinally spaced locations along the cable whereby an output signal of different magnitude is produced by the cable as a result of a force of constant magnitude applied externally to said locations along the cable, means for translating an attempted intrusion of said boundary into a mechanical force applied externally to said cables, circuit means connected to said cables for comparing the magnitudes of the respective cable output signals and producing an output proportional to the difference in the signal magnitudes, and indicator means responsive to the output of said circuit means for identifying the location along said boundary of an attempted intrusion.
Claim 8
Dependent Claim
160 words
An intrusion detection system comprising first and second laterally proximate coaxial electret cables extending along the boundary of an area to be protected, each of said cables having an electret filler with an electrostatic charge of predetermined strength affecting the sensitivity of the cable, at least one of said cables having a sensitivity that is different at longitudinally spaced locations along the cable whereby an output signal of different magnitude is produced by the cable as a result of a force of constant magnitude applied externally to said locations along the cable, means for translating an attempted intrusion of said boundary into a mechanical force applied externally to said cables, circuit means connected to said cables for comparing the magnitudes of the respective cable output signals and producing an output proportional to the difference in the signal magnitudes, and indicator means responsive to the output of said circuit means for identifying the location along said boundary of an attempted intrusion.
Claim 9
Dependent Claim
40 words
The system according to claim 6 in which said cables comprise a plurality of longitudinally successive sections of predetermined lengths, the sensitivity of said one cable being substantially constant throughout each section but being different for each of said sections.
Claim 10
Dependent Claim
21 words
The system according to claim 6 in which the sensitivity of said one cable changes linearly with distance along said boundary.
Claim 11
Dependent Claim
65 words
The system according to claim 6 with signal processor means operatively connected to the outputs of said cables and adapted to pass signals characteristic of an intruder and to block other signals, and means responsive to the output from said processor means for enabling said circuit means when intruder generated signals are received and for disabling said circuit means when said other signals are received.
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) | 1977-09-16 | 1978-03-18 | 1978-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-16 | 1982-03-18 | 1982-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-16 | 1986-03-18 | 1986-09-17 | $7700.00 | Window Closed / Lapsed |