Patent US3845461A successfully refreshed from Google Patents.
US3845461A
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Intrusion detection system
Assignee: Northrop Grumman Innovation Systems LLC
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Filing: 1973-06-25
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Granted: 1974-10-29
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Expires: 1993-06-25
Abstract
Abstract An improved intrusion detection system operating in either ultrasonic or electromagnetic wavelengths using a single transducer, which distinguishes between intruder movement toward the transducer or away from it, and gives no alarm unless intruder movement has a net component of approach or retreat.
Inventors
- 👤 D Foreman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:38
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/16; G08B13/1609; G08B13/1618; G08B13/1627; G01; G01S; G01S13/00; G01S13/02; G01S13/50; G01S13/52; G01S13/56
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
176 words
Apparatus for indicating the presence in a monitored space of a body having a component of movement toward or away from the indicating apparatus comprising, in combination: a single transducer operable to transmit radiated energy into a space and to receive said radiated energy when reflected from bodies in said space; a source of radiated energy; means interconnecting said source and said transducer so that energy from said source may be transmitted into said space and may also combine with reflected energy from said space to comprise a first signal having a first component determined by said source and a second component determined by the movement of any reflecting body in the space; detecting means connected to receive said first signal for giving a pair of further signals, in phase quadrature, in response to said component of movement of said body in said space, the phase relation therebetween reversing with reversal in the sense of said component; and means for deriving from said further signal an output which reverses with reversal of the phase relation therebetween.
Claim 2
Dependent Claim
176 words
Apparatus for indicating the presence in a monitored space of a body having a component of movement toward or away from the indicating apparatus comprising, in combination: a single transducer operable to transmit radiated energy into a space and to receive said radiated energy when reflected from bodies in said space; a source of radiated energy; means interconnecting said source and said transducer so that energy from said source may be transmitted into said space and may also combine with reflected energy from said space to comprise a first signal having a first component determined by said source and a second component determined by the movement of any reflecting body in the space; detecting means connected to receive said first signal for giving a pair of further signals, in phase quadrature, in response to said component of movement of said body in said space, the phase relation therebetween reversing with reversal in the sense of said component; and means for deriving from said further signal an output which reverses with reversal of the phase relation therebetween.
Claim 3
Dependent Claim
24 words
Apparatus according to claim 1 in which the interconnecting means includes a hybrid junction energized from said source with two signals in phase quadrature.
Claim 4
Dependent Claim
23 words
Apparatus according to claim 2 in which said hybrid junction comprises a hybrid coil and said transducer converts electrical energy to acoustical energy.
Claim 5
Dependent Claim
23 words
Apparatus according to claim 2 in which said hybrid junction is a rat race and said transducer is a microwave or UHF antenna.
Claim 6
Dependent Claim
120 words
In combination: a hybrid junction having first and second mutually decoupled arms which are severally coupled to a third arm; means coupling power to said first and second arms in phase quadrature; transducer means coupled to said third arm to emit power coupled from said first and second arms and to accept power impinging thereon for coupling to said first and second arms; amplitude detectors connected to said first and second arms respectively; multiplying means for giving an output representative of the products of two inputs thereto; means connecting said detectors to supply the inputs to said multiplying means, one of the connecting means including a phase shifter; and integrating means connected to receive the output of said multiplying means
Claim 7
Dependent Claim
120 words
In combination: a hybrid junction having first and second mutually decoupled arms which are severally coupled to a third arm; means coupling power to said first and second arms in phase quadrature; transducer means coupled to said third arm to emit power coupled from said first and second arms and to accept power impinging thereon for coupling to said first and second arms; amplitude detectors connected to said first and second arms respectively; multiplying means for giving an output representative of the products of two inputs thereto; means connecting said detectors to supply the inputs to said multiplying means, one of the connecting means including a phase shifter; and integrating means connected to receive the output of said multiplying means
Claim 8
Dependent Claim
125 words
In combination: a hybrid coil having first and second mutually decoupled windings which are severally coupled to a third winding; means coupling alternating electric currents of ultrasonic frequency to said first and second windings in phase quadrature; transducer means coupled to said third winding to emit ultrasonic acoustic power coupled from said first and second windings and to accept power for coupling to said first and second windings; amplitude detectors connected to said first and second windings respectively; multiplying means for giving an output representative of the product of two inputs thereto; means connecting said detectors to supply the inputs to said multiplying means, one of the connecting means including a phase shifter; and integrating means connected to receive the output of said multiplying means.
Claim 9
Dependent Claim
125 words
In combination: a hybrid coil having first and second mutually decoupled windings which are severally coupled to a third winding; means coupling alternating electric currents of ultrasonic frequency to said first and second windings in phase quadrature; transducer means coupled to said third winding to emit ultrasonic acoustic power coupled from said first and second windings and to accept power for coupling to said first and second windings; amplitude detectors connected to said first and second windings respectively; multiplying means for giving an output representative of the product of two inputs thereto; means connecting said detectors to supply the inputs to said multiplying means, one of the connecting means including a phase shifter; and integrating means connected to receive the output of said multiplying means.
References Cited (Backward Citations)
US3703722A
Cited
US3781773A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-28 | 1978-04-29 | 1978-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-28 | 1982-04-29 | 1982-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-28 | 1986-04-29 | 1986-10-29 | $7700.00 | Window Closed / Lapsed |