US3832704A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dual wire intruder detector
Assignee: Honeywell Inc
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Filing: 1973-06-19
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Granted: 1974-08-27
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Expires: 1993-06-19
Abstract
Abstract A perimeter security system comprising a strain sensitive line sensor in the form of dual magnetostrictive thin film plated wires having uniaxial anisotropy. The plated wire line sensor is preferably buried in a shallow trench or the like and detects intrusion in the vicinity of the line as the line sensor is stressed by the intruder causing a displacement of the earth. One of the dual plated wires is made to have a different degree of magnetostrictiveness than the other. The detection system is selectively sensitive to the motion of a mass on a surface, but tends to reject magnetic disturbances which effectively produce the same signal.
Inventors
- 👤 V Kardashian
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:41
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/22; G08B13/24; G08B13/2491; G08B13/2497; G01; G01L; G01L1/00; G01L1/12; G01L1/125
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
225 words
A strain sensitive line sensor detection system which senses local movement of a medium being intruded upon, the system comprising: an extended length of a first wire on which is plated an anisotropic thin film having a first composition of nickel-iron alloy plating exhibiting a first degree of magnetostrictive response; an extended length of a second wire on which is plated an anisotropic thin film having a different composition of nickel-iron alloy plating exhibiting a different degree of magnetostrictive response, said first and second wires each having the same response to a magnetic field, said wires having an insulative covering; means energizing said first and second plated wires from a source of alternating type current; said first and second plated wires being positioned in a side by side relation in said medium so that while magnetic field changes cause equal signals on said first and second wires, movement of said medium which strains said wires causes differing signals in one wire than the other because of the differing degrees of magnetostrictive response; and means connecting the signals from said first and second plated wires to first and second differential inputs of a differential amplifier whereby said equal signals on said wires such as caused by a magnetic disturbance cancel one another out in the amplifier while the differing strain produced signals are summed and amplified.
Claim 2
Dependent Claim
225 words
A strain sensitive line sensor detection system which senses local movement of a medium being intruded upon, the system comprising: an extended length of a first wire on which is plated an anisotropic thin film having a first composition of nickel-iron alloy plating exhibiting a first degree of magnetostrictive response; an extended length of a second wire on which is plated an anisotropic thin film having a different composition of nickel-iron alloy plating exhibiting a different degree of magnetostrictive response, said first and second wires each having the same response to a magnetic field, said wires having an insulative covering; means energizing said first and second plated wires from a source of alternating type current; said first and second plated wires being positioned in a side by side relation in said medium so that while magnetic field changes cause equal signals on said first and second wires, movement of said medium which strains said wires causes differing signals in one wire than the other because of the differing degrees of magnetostrictive response; and means connecting the signals from said first and second plated wires to first and second differential inputs of a differential amplifier whereby said equal signals on said wires such as caused by a magnetic disturbance cancel one another out in the amplifier while the differing strain produced signals are summed and amplified.
Claim 3
Dependent Claim
47 words
The invention according to claim 1 wherein said first composition of nickel-iron alloy plating has more than 80 percent Ni and exhibits a negative magnetostrictive response and wherein said second composition of nickel-iron alloy plating has less than 80 percent Ni and exhibits a positive magnetostrictive response.
Claim 4
Dependent Claim
51 words
The invention according to claim 1 wherein said first composition of NiFe permalloy plating has more than 80 percent Ni and exhibits a relatively high negative magnetostrictive response and wherein said second composition of NiFe permalloy plating has somewhat more than 80 percent Ni and exhibits a lesser negative magnetostrictive response.
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) | 1977-08-26 | 1978-02-25 | 1978-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-26 | 1982-02-25 | 1982-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-26 | 1986-02-25 | 1986-08-27 | $7700.00 | Window Closed / Lapsed |