US5024092A
Expired / Lapsed
US
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Method and apparatus for selective transmission and reflection of sound through a solid
Assignee: Northrop Grumman Corp
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Filing: 1990-08-16
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Granted: 1991-06-18
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Expires: 2010-08-16
Abstract
Abstract A device is disclosed which allows an object to be tuned to an incoming sound wave magnitude and wavelength, such that the sound wave will alternatively be passed therethrough without detectable reflection or be completely reflected. The apparatus is intended to be mounted within a hollow object and adjust the perceived distance between the exterior walls of that object to mimic a single thick wall. A signal processing means is supplied which detects the sound wave magnitude and wavelength impinging on the wall facing the sound wave source. The wavelength is passed to the signal processing means, which transmits a complimentary signal to the second wall of the hollow object. The complimentary signal allows the hollow object to resonate as a whole as if it were a solid of a thickness much different from its actual thickness, allowing the sound wave to pass undisturbed therethrough or be reflected therefrom.
Inventors
- 👤 Ronald T. Harrold
- 👤 Zal N. Sanjana
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:34
CPC Classifications
G; G10; G10K; G10K11/00; G10K11/18; G10K11/20
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
213 words
An apparatus for facilitating the complete transmission of sound waves through an object, the object having at least two walls forming a known distance therebetween, the apparatus comprising: sound wave detection means affixed to a first wall of the object, the first wall being that which is closest to a source of initial sound waves; first transducer means affixed to said sound wave detection means, said first transducer means adapted to transform said initial sound waves into electronic signals; second transducer means for conversion of electronic signals into secondary sound waves; sound wave emission means affixed to said second transducer means and a second wall of the object, the second wall being opposite said first wall; and signal processing means, electronically connected to said first and second transducer means, said signal processing means adapted to: calculate the wavelength of said initial sound waves impinging on said sound wave detection means, calculate the time necessary to pass a distance one half of said wavelength minus the known distance between said walls, and emit an electronic signal to said second transducer means, the electronic signal timed such that it will cause the emission of secondary sound waves of identical wavelength as said initial sound waves from said sound wave emission means at the time calculated.
Claim 2
Independent Claim
213 words
An apparatus for facilitating the complete transmission of sound waves through an object, the object having at least two walls forming a known distance therebetween, the apparatus comprising: sound wave detection means affixed to a first wall of the object, the first wall being that which is closest to a source of initial sound waves; first transducer means affixed to said sound wave detection means, said first transducer means adapted to transform said initial sound waves into electronic signals; second transducer means for conversion of electronic signals into secondary sound waves; sound wave emission means affixed to said second transducer means and a second wall of the object, the second wall being opposite said first wall; and signal processing means, electronically connected to said first and second transducer means, said signal processing means adapted to: calculate the wavelength of said initial sound waves impinging on said sound wave detection means, calculate the time necessary to pass a distance one half of said wavelength minus the known distance between said walls, and emit an electronic signal to said second transducer means, the electronic signal timed such that it will cause the emission of secondary sound waves of identical wavelength as said initial sound waves from said sound wave emission means at the time calculated.
Claim 3
Dependent Claim
33 words
An apparatus as described in claim 1, wherein said sound wave detection means is constructed of a material which matches the coefficient of thermal expansion of the wall to which it is affixed.
Claim 4
Dependent Claim
35 words
An apparatus as described in claim 2, wherein said sound wave detection means is constructed of a material selected from the group consisting of nichrome, polyester-fiberglas, optical fiber, steel, sapphire, quartz, plastics, glass and epoxy-fiberglass.
Claim 5
Dependent Claim
30 words
An apparatus as described in claim 3, wherein said sound wave detection means is constructed of a material having an attenuation of less than 3 decibels per meter of length.
Claim 6
Dependent Claim
33 words
An apparatus as described in claim 1, wherein said sound wave emission means is constructed of a material which matches the coefficient of thermal expansion o the wall to which it is affixed.
Claim 7
Dependent Claim
35 words
An apparatus as described in claim 5, wherein said sound wave emission means is constructed of a material selected from the group consisting of nichrome, polyester-fiberglas, optical fiber, steel, sapphire, quartz, plastics, glass and epoxy-fiberglass.
Claim 8
Dependent Claim
30 words
An apparatus as described in claim 5, wherein said sound wave emission means is constructed of a material having an attenuation of less than 3 decibels per meter of length.
Claim 9
Dependent Claim
56 words
An apparatus as described in claim 1, wherein said sound wave detection means and said sound wave emission means are surrounded by a first medium having an acoustic impedance, the sound wave detection means and the sound wave emission means being constructed of a material having an acoustic impedance significantly different from the surrounding first medium.
Claim 10
Dependent Claim
36 words
An apparatus as described in claim 8, wherein said sound wave detection means and the sound wave emission means have an acoustic impedance that is about 30 times greater than that of the surrounding first medium.
Claim 11
Dependent Claim
44 words
An apparatus as described in claim 8, wherein said initial sound waves move through a second medium, and wherein the second medium exists between the first and second walls of the object, said second medium having the same acoustic impedance as the first medium.
Claim 12
Dependent Claim
32 words
An apparatus as described in claim 8, wherein said sound wave detection means and said sound wave emission means have an acoustic impedance equal to the walls to which they are affixed.
Claim 13
Dependent Claim
26 words
An apparatus as described in claim 1, wherein said signal processing means further comprises a detection amplifier, time calculation and delay circuitry and a transmission amplifier.
Claim 14
Dependent Claim
22 words
An apparatus as described in claim 12, wherein said detection amplifier has a gain in the range of 10 to 100 dB.
Claim 15
Dependent Claim
24 words
An apparatus as described in claim 1, further comprising a layer of sound absorbing material affixed to one of the walls of the object.
Claim 16
Dependent Claim
35 words
An apparatus as described in claim 1, wherein either of said sound wave detection means and said sound wave emission means are mounted to an exterior surface of one of said walls of the object.
Claim 17
Dependent Claim
32 words
An apparatus as described in claim 1, wherein either of said sound wave detection means and said sound wave emission means are mounted interior to one of said walls of the object.
Claim 18
Independent Claim
213 words
An apparatus for facilitating the complete reflection of sound waves from an object, the object having at least two walls forming a known distance therebetween, the apparatus comprising: sound wave detection means affixed to a first wall of the object, the first wall being that which is closest to a source of initial sound waves; first transducer means affixed to said sound wave detection means, said first transducer means adapted to transform said initial sound waves into electronic signals; second transducer means for conversion of electronic signals into secondary sound waves; sound wave emission means affixed to said second transducer means and a second wall of the object, the second wall being opposite said first wall; and signal processing means, electronically connected to said first and second transducer means, said signal processing means adapted to: calculate the wavelength of said initial sound waves impinging on said sound wave detection means, calculate the time necessary to pass a distance one quarter of said wavelength minus the known distance between said walls, and emit an electronic signal to said second transducer means, the electronic signal timed such that it will cause the emission of secondary sound waves of identical wavelength as said initial sound waves from said sound wave emission means at the time calculated.
Claim 19
Independent Claim
213 words
An apparatus for facilitating the complete reflection of sound waves from an object, the object having at least two walls forming a known distance therebetween, the apparatus comprising: sound wave detection means affixed to a first wall of the object, the first wall being that which is closest to a source of initial sound waves; first transducer means affixed to said sound wave detection means, said first transducer means adapted to transform said initial sound waves into electronic signals; second transducer means for conversion of electronic signals into secondary sound waves; sound wave emission means affixed to said second transducer means and a second wall of the object, the second wall being opposite said first wall; and signal processing means, electronically connected to said first and second transducer means, said signal processing means adapted to: calculate the wavelength of said initial sound waves impinging on said sound wave detection means, calculate the time necessary to pass a distance one quarter of said wavelength minus the known distance between said walls, and emit an electronic signal to said second transducer means, the electronic signal timed such that it will cause the emission of secondary sound waves of identical wavelength as said initial sound waves from said sound wave emission means at the time calculated.
Claim 20
Dependent Claim
33 words
An apparatus as described in claim 17, wherein said sound wave detection means is constructed of a material which matches the coefficient of thermal expansion of the wall to which it is affixed.
Claim 21
Dependent Claim
35 words
An apparatus as described in claim 18, wherein said sound wave detection means is constructed of a material selected from the group consisting of nichrome, polyester-fiberglas, optical fiber, steel, sapphire, quartz, plastics, glass and epoxy-fiberglass.
Claim 22
Dependent Claim
30 words
An apparatus as described in claim 19, wherein said sound wave detection means is constructed of a material having an attenuation of less than 3 decibels per meter of length.
Claim 23
Dependent Claim
33 words
An apparatus as described in claim 17, wherein said sound wave emission means is constructed of a material which matches the coefficient of thermal expansion of the wall to which it is affixed.
Claim 24
Dependent Claim
35 words
An apparatus as described in claim 21, wherein said sound wave emission means is constructed of a material selected from the group consisting of nichrome, polyester-fiberglas, optical fiber, steel, sapphire, quartz, plastics, glass and epoxy-fiberglass.
Claim 25
Dependent Claim
30 words
An apparatus as described in claim 21, wherein said sound wave emission means is constructed of a material having an attenuation of less than 10 decibels per meter of length.
Claim 26
Dependent Claim
56 words
An apparatus as described in claim 17, wherein said sound wave detection means and said sound wave emission means are surrounded by a first medium having an acoustic impedance, the sound wave detection means and the sound wave emission means being constructed of a material having an acoustic impedance significantly different from the surrounding first medium.
Claim 27
Dependent Claim
36 words
An apparatus as described in claim 24, wherein said sound wave detection means and the sound wave emission means have an acoustic impedance that is about 30 times greater than that of the surrounding first medium.
Claim 28
Dependent Claim
44 words
An apparatus as described in claim 24, wherein said initial sound waves move through a second medium, and wherein the second medium exists between the first and second walls of the object, said second medium having the same acoustic impedance as the first medium.
Claim 29
Dependent Claim
32 words
An apparatus as described in claim 24, wherein said sound wave detection means and said sound wave emission means have an acoustic impedance equal to the walls to which they are affixed.
Claim 30
Dependent Claim
26 words
An apparatus as described in claim 17, wherein said signal processing means further comprises a detection amplifier, time calculation and delay circuitry and a transmission amplifier.
Claim 31
Dependent Claim
22 words
An apparatus as described in claim 28, wherein said detection amplifier has a gain in the range of 10 to 100 dB.
Claim 32
Independent Claim
322 words
An apparatus for facilitating the complete transmission of sound waves through an object, the object having at least two walls forming a known distance therebetween, the apparatus comprising: first sound wave detection means affixed to a first wall of the object, the first wall being that which is closest to a source of initial sound waves; first transducer means affixed to said first sound wave detection means, said first transducer means adapted to transform said initial sound waves into electronic signals; second transducer means for conversion of electronic signals into secondary sound waves; sound wave emission means affixed to said second transducer means and a second wall of the object, the second wall being opposite said first wall; second sound wave detection means, affixed to said second wall of the object; third transducer means, affixed to said second sound wave detection means, for transformation of sound waves into electronic impules; and signal processing means, electronically connected to said first, second and third transducer means, said signal processing means adapted to: calculate the wavelength of said initial sound waves impinging on said first sound wave detection means, calculate the time necessary to pass a distance one half of said wavelength minus the known distance between said walls, and confirm the wavelength of the initial sound waves impinging on said first sound wave detection means by comparison to said first sound waves impinging on said second sound wave detection means, emit an electronic signal to said second transducer means, the electronic signal timed such that it will cause the emission of secondary sound waves of identical wavelength as said initial sound waves from said sound wave emission means at the time calculated, and adjust the timing of the electronic signal with respect to the comparison of the wavelength of the initial sound waves, impinging on said first sound wave detection means and said first sound waves impinging on said second sound wave detection means.
Claim 33
Independent Claim
322 words
An apparatus for facilitating the complete transmission of sound waves through an object, the object having at least two walls forming a known distance therebetween, the apparatus comprising: first sound wave detection means affixed to a first wall of the object, the first wall being that which is closest to a source of initial sound waves; first transducer means affixed to said first sound wave detection means, said first transducer means adapted to transform said initial sound waves into electronic signals; second transducer means for conversion of electronic signals into secondary sound waves; sound wave emission means affixed to said second transducer means and a second wall of the object, the second wall being opposite said first wall; second sound wave detection means, affixed to said second wall of the object; third transducer means, affixed to said second sound wave detection means, for transformation of sound waves into electronic impules; and signal processing means, electronically connected to said first, second and third transducer means, said signal processing means adapted to: calculate the wavelength of said initial sound waves impinging on said first sound wave detection means, calculate the time necessary to pass a distance one half of said wavelength minus the known distance between said walls, and confirm the wavelength of the initial sound waves impinging on said first sound wave detection means by comparison to said first sound waves impinging on said second sound wave detection means, emit an electronic signal to said second transducer means, the electronic signal timed such that it will cause the emission of secondary sound waves of identical wavelength as said initial sound waves from said sound wave emission means at the time calculated, and adjust the timing of the electronic signal with respect to the comparison of the wavelength of the initial sound waves, impinging on said first sound wave detection means and said first sound waves impinging on said second sound wave detection means.
Claim 34
Dependent Claim
48 words
An apparatus as described in claim 30, wherein the second wall has a first surface and a second surface opposite said first surface and said second sound wave detection means is affixed to said first surface and said sound wave emission means is affixed to said second surface.
Claim 35
Independent Claim
109 words
A method for facilitating the complete transmission of sound waves through an object, the object having at least two walls forming a known distance therebetween, the method comprising the steps of: detecting the wavelength of said sound waves impinging on a first wall of the object; calculating the time necessary for said sound waves to pass a distance one half of said wavelength minus the known distance between said walls; and emitting an electronic signal from a second wall, the electronic signal timed such that it will cause the emission of secondary sound waves of identical wavelength as said sound waves from said second wall at the time calculated.
Claim 36
Independent Claim
109 words
A method for facilitating the complete transmission of sound waves through an object, the object having at least two walls forming a known distance therebetween, the method comprising the steps of: detecting the wavelength of said sound waves impinging on a first wall of the object; calculating the time necessary for said sound waves to pass a distance one half of said wavelength minus the known distance between said walls; and emitting an electronic signal from a second wall, the electronic signal timed such that it will cause the emission of secondary sound waves of identical wavelength as said sound waves from said second wall at the time calculated.
Claim 37
Independent Claim
135 words
A method for facilitating the complete transmission of sound waves through an object, the object having at least two walls forming a known distance therebetween, the method comprising the steps of: detecting the wavelength of said sound waves impinging on a first wall of the object; calculating the time necessary for said sound waves to pass a distance one half of said wavelength minus the known distance between said walls; emitting an electronic signal from a second wall, the electronic signal timed such that it will cause the emission of secondary sound waves of identical wavelength as said sound waves from said second wall at the time calculated; detecting said sound waves a second time from a point on said second wall; and adjusting the timing of said electronic signal based on said second detection.
Claim 38
Independent Claim
135 words
A method for facilitating the complete transmission of sound waves through an object, the object having at least two walls forming a known distance therebetween, the method comprising the steps of: detecting the wavelength of said sound waves impinging on a first wall of the object; calculating the time necessary for said sound waves to pass a distance one half of said wavelength minus the known distance between said walls; emitting an electronic signal from a second wall, the electronic signal timed such that it will cause the emission of secondary sound waves of identical wavelength as said sound waves from said second wall at the time calculated; detecting said sound waves a second time from a point on said second wall; and adjusting the timing of said electronic signal based on said second detection.
Claim 39
Independent Claim
112 words
A method for facilitating the complete reflection of sound waves from a wall of an object, the object having at least two walls forming a known distance therebetween, the method comprising the steps of: detecting the wavelength of said sound waves impinging on a first wall of the object; calculating the time necessary for said sound waves to pass a distance one quarter of said wavelength minus the known distance between said walls; and emitting an electronic signal from a second wall, the electronic signal timed such that it will cause the emission of secondary sound waves of identical wavelength as said sound waves from said second wall at the time calculated.
Claim 40
Independent Claim
112 words
A method for facilitating the complete reflection of sound waves from a wall of an object, the object having at least two walls forming a known distance therebetween, the method comprising the steps of: detecting the wavelength of said sound waves impinging on a first wall of the object; calculating the time necessary for said sound waves to pass a distance one quarter of said wavelength minus the known distance between said walls; and emitting an electronic signal from a second wall, the electronic signal timed such that it will cause the emission of secondary sound waves of identical wavelength as said sound waves from said second wall at the time calculated.
References Cited (Backward Citations)
US4590803A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-06-17 | 1994-12-17 | 1995-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-06-17 | 1998-12-17 | 1999-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-06-17 | 2002-12-17 | 2003-06-18 | $7700.00 | Window Closed / Lapsed |