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US3982142A Expired / Lapsed US ⏱️ 0.0 years remaining

Piezoelectric transducer assembly and method for generating a cone shaped radiation pattern

Assignee: SONTRIX Inc
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Filing: 1974-05-20
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Granted: 1976-09-21
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Expires: 1994-05-20
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Abstract

Abstract A transducer assembly which generates a cone shaped radiation pattern concentric with a selected axis is formed by a piezoelectric element mounted in a cylindrical resonant cavity defined by a Helmholtz chamber. Circumferentially spaced apart and radially aligned circular apertures are formed in the chamber's cylindrical side wall and an inclined reflecting plate is spaced apart from the apertures a selected distance. The plate extends outwardly from the chamber at an angle of less than 90° to the chamber axis. The cone shaped radiation pattern is produced by generating a plurality of discrete spherical radiation patterns, combining these patterns to form an annular radiation pattern and partially reflecting the annular radiation pattern from an inclined reflection plate extending at an angle to the chamber axis of less than 90° to produce a cone shaped radiation pattern.

Inventors

  • 👤 Ralph W. Goble

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 11:19
CPC Classifications
G; G10; G10K; G10K11/00; G10K11/18; G10K11/26; G10K11/28; B; B06; B06B; B06B1/00; B06B1/02; B06B1/06; B06B1/0603; H; H04; H04R; H04R1/00; H04R1/20; H04R1/32; H04R1/34; H04R1/345

Claims Analysis

Total Claims: 26
Claim 1
Independent Claim 240 words
A piezoelectric transducer assembly for generating a radiation pattern of acoustical energy having a cone shaped cross section relative to a selected axis, said assembly comprising: a resonant chamber having side walls and closed ends and a selected resonant frequency, said chamber being positioned with its longitudinal axis parallel with the side walls and defining the selected axis of said assembly, said chamber having a plurality of spaced apart sound transmitting apertures defined in its side walls about its longitudinal axis, the centerpoints of said apertures defining a plane substantially perpendicular to said selected axis; piezoelectric transducer means mounted within said chamber for generating therein along said selected axis a spherical radiation pattern of acoustical energy at the resonant frequency of said chamber whereby similar radiation patterns of said acoustical radiation are emitted from each of said apertures along their center axes; and, means defining a conical reflecting surface positioned at an acute angle β to the longitudinal axis of the chamber to receive and reflect acoustical waves radiating from the centerpoints of said apertures towards said reflecting surface, said conical reflecting surface being spaced apart from the plane of the centerpoints of said apertures a predetermined distance y at which acoustical waves at said resonant frequency radiating from said apertures towards said reflecting surface are reflected away from said reflecting surface in a cone shaped radiation pattern, said distance y being measured along the side walls of the chamber.
Claim 2
Dependent Claim 240 words
A piezoelectric transducer assembly for generating a radiation pattern of acoustical energy having a cone shaped cross section relative to a selected axis, said assembly comprising: a resonant chamber having side walls and closed ends and a selected resonant frequency, said chamber being positioned with its longitudinal axis parallel with the side walls and defining the selected axis of said assembly, said chamber having a plurality of spaced apart sound transmitting apertures defined in its side walls about its longitudinal axis, the centerpoints of said apertures defining a plane substantially perpendicular to said selected axis; piezoelectric transducer means mounted within said chamber for generating therein along said selected axis a spherical radiation pattern of acoustical energy at the resonant frequency of said chamber whereby similar radiation patterns of said acoustical radiation are emitted from each of said apertures along their center axes; and, means defining a conical reflecting surface positioned at an acute angle β to the longitudinal axis of the chamber to receive and reflect acoustical waves radiating from the centerpoints of said apertures towards said reflecting surface, said conical reflecting surface being spaced apart from the plane of the centerpoints of said apertures a predetermined distance y at which acoustical waves at said resonant frequency radiating from said apertures towards said reflecting surface are reflected away from said reflecting surface in a cone shaped radiation pattern, said distance y being measured along the side walls of the chamber.
Claim 3
Dependent Claim 35 words
The invention of claim 1 wherein the predetermined distance is defined by the equation y = m λ cos β, where λ is the resonant wavelength at said frequency and m is a whole number.
Claim 4
Dependent Claim 15 words
The invention defined in claim 1 wherein the acute angle β is greater than 45°.
Claim 5
Dependent Claim 11 words
The invention defined in claim 1, wherein said apertures are circular.
Claim 6
Dependent Claim 13 words
The invention defined in claim 1, wherein said apertures are equidistantly spaced apart.
Claim 7
Dependent Claim 32 words
The invention defined in claim 1, wherein said apertures are circular and are equidistantly spaced apart at a distance between their centerpoints equal to approximately one wavelength λ at said resonant frequency.
Claim 8
Dependent Claim 25 words
The invention defined in claim 6, wherein the diameter of each of said apertures is equal to approximately one-half wavelength λ/2 at said resonant frequency.
Claim 9
Dependent Claim 52 words
The invention defined in claim 7, wherein said conical reflecting surface is spaced apart from the plane of the centerpoints of said apertures a distance measured along the side walls of the chamber equal approximately to a whole number of wavelengths at said resonant frequency multiplied by the cos of angle β.
Claim 10
Dependent Claim 15 words
The invention defined in claim 8, wherein said resonant frequency is an ultrasonic resonant frequency.
Claim 11
Dependent Claim 18 words
The invention defined in claim 9, wherein said transducer means includes a flat plate-like bender type piezoelectric element.
Claim 12
Dependent Claim 36 words
The invention defined in claim 1, wherein said apertures are sized, shaped and spaced apart to emit substantially spherical patterns of radiation of acoustical energy at said resonant frequency which combine in phase with each other.
Claim 13
Dependent Claim 12 words
The invention defined in claim 1, wherein the resonant chamber is cylindrical.
Claim 14
Dependent Claim 15 words
The invention defined in claim 1, wherein the acute angle β is less than 45°.
Claim 15
Dependent Claim 172 words
A piezoelectric transducer assembly for generating a cone shaped radiation pattern of acoustical energy around a selected axis, comprising: means for generating at each of a plurality of substantially equidistantly spaced apart points located substantially equidistantly from said selected axis in a plane substantially perpendicular to said selected axis a similar spherical radiation pattern of acoustical energy which emanates from the one of said points at which generated radially outwardly relative to said selected axis, said spherical radiation patterns being generated at a same selected wavelength to add to form an annular shaped outwardly radiating pattern of acoustical energy at said selected wavelength, said generating means including a piezoelectric transducer element and being positioned to generate said annular shaped radiation pattern concentric with said selected axis; and means defining a conical reflecting surface positioned at an acute angle to said selected axis and positioned with respect to said generating means for reflecting a selected portion of said annular shaped radiation pattern to form said cone shaped radiation pattern around said selected axis.
Claim 16
Dependent Claim 172 words
A piezoelectric transducer assembly for generating a cone shaped radiation pattern of acoustical energy around a selected axis, comprising: means for generating at each of a plurality of substantially equidistantly spaced apart points located substantially equidistantly from said selected axis in a plane substantially perpendicular to said selected axis a similar spherical radiation pattern of acoustical energy which emanates from the one of said points at which generated radially outwardly relative to said selected axis, said spherical radiation patterns being generated at a same selected wavelength to add to form an annular shaped outwardly radiating pattern of acoustical energy at said selected wavelength, said generating means including a piezoelectric transducer element and being positioned to generate said annular shaped radiation pattern concentric with said selected axis; and means defining a conical reflecting surface positioned at an acute angle to said selected axis and positioned with respect to said generating means for reflecting a selected portion of said annular shaped radiation pattern to form said cone shaped radiation pattern around said selected axis.
Claim 17
Independent Claim 143 words
The method of generating a conical shaped radiation pattern of acoustical energy of a selected wavelength around a selected axis, comprising: generating at each of a plurality of substantially equidistantly spaced apart points located substantially equidistantly from said selected axis in a plane substantially perpendicular to said selected axis a similar spherical radiation pattern of acoustical energy which emanates from the one of said points at which generated radially outwardly relative to said selected axis, said spherical radiation patterns being generated at a same selected wavelength to add to form an annular outwardly radiating pattern of acoustical energy at said selected wavelength concentric with said selected axis; and reflecting a selected portion of the acoustical waves of said annular radiation pattern by a conical reflecting surface positioned at a selected angle β to said selected axis to produce a cone shaped radiation pattern.
Claim 18
Independent Claim 143 words
The method of generating a conical shaped radiation pattern of acoustical energy of a selected wavelength around a selected axis, comprising: generating at each of a plurality of substantially equidistantly spaced apart points located substantially equidistantly from said selected axis in a plane substantially perpendicular to said selected axis a similar spherical radiation pattern of acoustical energy which emanates from the one of said points at which generated radially outwardly relative to said selected axis, said spherical radiation patterns being generated at a same selected wavelength to add to form an annular outwardly radiating pattern of acoustical energy at said selected wavelength concentric with said selected axis; and reflecting a selected portion of the acoustical waves of said annular radiation pattern by a conical reflecting surface positioned at a selected angle β to said selected axis to produce a cone shaped radiation pattern.
Claim 19
Dependent Claim 27 words
The method of claim 15 including the step of reflecting directly radiating waves from a reflecting surface in phase with the directly radiated waves to reinforce same.
Claim 20
Dependent Claim 57 words
The invention defined in claim 15, wherein the plane defined by said points being spaced apart from said conical reflection surface at the location of said points a distance measured along a normal to the plane of said points equal approximately to a whole number of wavelengths at said selected wavelength multiplied by the cos of β.
Claim 21
Dependent Claim 14 words
The invention defined in claim 17, wherein the angle β is greater than 45°.
Claim 22
Dependent Claim 14 words
The invention defined in claim 17, wherein the angle β is less than 45°.
Claim 23
Dependent Claim 18 words
The invention defined in claim 1, wherein said conical reflecting surface is positioned concentric with said selected axis.
Claim 24
Dependent Claim 36 words
The invention defined in claim 21, wherein said predetermined distance is defined by the equation y = mλ cos β, where λ is the wavelength at said selected resonant frequency and m is a whole number.
Claim 25
Dependent Claim 18 words
The invention defined in claim 14, wherein said conical reflecting surface is positioned concentric with said selected axis.
Claim 26
Dependent Claim 17 words
The method of claim 15, wherein said conical reflected surface is positioned concentric with said selected axis.

References Cited (Backward Citations)

US1985251A Cited
US2005741A Cited
US3243768A Cited
US3325779A Cited
US3703652A Cited
US3742442A Cited
US3748637A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1979-09-21 1980-03-22 1980-09-21 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1983-09-21 1984-03-22 1984-09-21 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1987-09-21 1988-03-22 1988-09-21 $7700.00 Window Closed / Lapsed

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