US2779880A - Ultra-sonic wave transducers - Google Patents

Ultra-sonic wave transducers Download PDF

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Publication number
US2779880A
US2779880A US277330A US27733052A US2779880A US 2779880 A US2779880 A US 2779880A US 277330 A US277330 A US 277330A US 27733052 A US27733052 A US 27733052A US 2779880 A US2779880 A US 2779880A
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US
United States
Prior art keywords
ultra
transducer
wave
waves
sonic
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US277330A
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English (en)
Inventor
Malherbe Georges
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Umicore NV SA
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Acec
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Filing date
Publication date
Priority to FR1034141D priority Critical patent/FR1034141A/fr
Priority to CH304763D priority patent/CH304763A/fr
Priority to GB6654/52A priority patent/GB700151A/en
Application filed by Acec filed Critical Acec
Priority to US277330A priority patent/US2779880A/en
Priority to FR64065D priority patent/FR64065E/fr
Priority to FR64064D priority patent/FR64064E/fr
Application granted granted Critical
Publication of US2779880A publication Critical patent/US2779880A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/18—Methods or devices for transmitting, conducting or directing sound
    • G10K11/26—Sound-focusing or directing, e.g. scanning
    • G10K11/28—Sound-focusing or directing, e.g. scanning using reflection, e.g. parabolic reflectors

Definitions

  • the present invention relates todevices intended to transmit elastic waves, an'd'particularly ultra-sonic waves;
  • Ultra-sonic wave transducers produced in the. form ofturgescent feelers generally work well and are in current use.
  • ultra sonic wave transducers as now constructed in the form of turgescent feelers, comprise a hollow body of cylindrical general shape, filled with a wave conducting liquid, the two ends being respectively closed by. a piezo-electric quartz crystal element capable of emitting ultra-sonic waves and by a flexible wall capable of bulging under the pressure of the filling liquid and of engaging snugly a portion of the surface of a body to beexamined'or treated, without any appreciable air gap between the two surfaces in contact.
  • directivity i. e.
  • the diameter of the emitter device is about 20 mm. and the external diameter of the cylin drical container is about 40 mm.
  • Another solution which might be considered consists in using, with a quartz crystal wave emitter of normal dimension, for example mm. diameter, a hollow supporting member of frusto-conical shape instead of the cone frustum being coincident with that of'the crystal,
  • the present invention provides a wave .transducer of small dimensions at the place of contact with the body.
  • the invention relates to an improvement in ultra-sonic wave transducers with liquid conducting medium, like the turgescent feelers described in theyaforesaid patent application, and consisting in the fact that the container enclosing the liquid conducting the ultra-sonic waves from the wave-emitter device to a body to be examined or treated.
  • the said waves comprises two hollow frusto-conical portions arranged coaxially and joined at their small bases, the two ends'of the convergent-divergent double cone frustum thus constituted being of different cross-sectional areas, the Waveemitting device being disposed normally to the axis'of the double cone frustum andat its larger end, and the smallerend of the double cone frustum, closed by a flexible wall, constituting the outlet for the ultra-sonic waves.
  • Fig. 1 represents diagrammatically an ultra-sonic wave transducer such as described-in the aforesaid patent application.
  • Fig. 1a is a graph of directivity of the transducer represented in Fig. l, as explained below.
  • Figs. 2. and 2a represent an ultra-sonic wave transducer Patented Jan. 29, 1957 inthe form of a convergent cone; and-its directivity Figs. 4 and '41; represent an ultra-sonic wave transducer according to the invention, having an interior profile in the form of a convergent-divergent double cone frustum, and its directivity graph.
  • Fig. '5 represents an example of the use of the .ultrasonic wave transducer according to the invention.
  • Fig. 6 represents another embodiment of the invention.
  • the character C designates wave-emitting means, e. g. a quartz crystal emitting ultra-sonic waves,
  • ' E is the. container forming the body orh'ousi'ng of the transducer and containing. a liquid'for conducting the ultra-sonic waves, P indicates aflexible wall, made, for example, of rubber, closing the end of the housing opposite-"the'crystal C and intended to establish proper contact between the transducer and the body to be examined ortreated with the ultra-sonic waves.
  • the housing E of the transducer comprises two hollow frusto-conical portions E1 and E2 which have a common axis X.
  • the small ends of the frusto-conica'l por: tions are of equal cross-section and are joined in a neck portion N.
  • the large ends of the frusto-conical portions E1 and E2 are of unequal size, the large end 21 of portion E1 being larger than the large end eg of portion E2.
  • the cross-section of the neck N is smaller than either of the ends e1 or e2 of the housing.
  • the walls of the housing E first converge to the neck N and then diverge to the opposite end as of the housing which is closed by the'flexible wall P.
  • the total amount of divergence is less than the total convergence so that the cross-sectional area of the end eg of the housing closed by the wall P is less than that of the end e1 Where the crystal C is located.
  • transducer and a receiver'of ultra-sonic waves were arranged in a medium conductive to the ultra-sonic waves, for example water, at a convenient distance from one another.
  • the receiver which was centered beforehand exactly on the axis of the emitter, was displaced along a straight line lying in a plane perpendicular to that axis. .At each position upon that straight line, the receiver was orientated accurately towards the emitter. There were then plotted'as ordinates upon the diagrams of Figs.
  • the sectional area of the emitter device was the same for the transducers of Figs. 1, 3 and 4, while the outlet area for the ultra-sonic waves from the transducer was the same for the transducers of Figs. 2, 3 and 4.
  • FIG. 4 is equal to that of the houscrystal.
  • thesmall area of the emitter device results in a lower sensitivity of the crystal and in spacing of the first and second lateral maxirna, under Huygens theory, farther from the axis of the transducer.
  • the inferior directivity of the transducer represented in Fig. 3 is due to the path followed by the portion of the wave emitted by theperipheral portion of the the emittedwave in thecase of Figs. 3 and 4 are shown. in broken lines and clearly illustrate the superior directivity of the wave transducer-according t0. the invention.
  • the paths of the waves reflected first by the. side walls of the portion E1 and then by the side walls of the portion E2 are parallel to one another. If the cone angle of the housing portion E2 is less than that of the housing portion E1, thepaths of the reflected waves in the peripheral portion of the housing are caused to converge and are'thereby focused.
  • Fig. 5 shows 'by way of example a practical applica tion ofthe improved transducer, where the transducer represented in Fig. 1 is not capable of being used.
  • T designates a metallic body to be examined with the ultrasonic waves, this body being provided with a recess or notch L the width of which is less than the diameter of the transducer represented in Fig. 1, but of such size that it is possible to introduce the improved transducer into V ducer while the transducer shown in Fig. 1 cannot be used.
  • the ultra-sonic wave transducer with liquid conducting medium, comprises two hollow paraboloids, aligned on the same axis, having the same focus and delimited by end sections perpendi cular to said axis, the principal parameters and the axial lengths of the two paraboloids being such that said end sections are of dilferent sizes, the two paraboloids axis at the larger of the delimiting end sections, and the smaller'ofthese end" sections being closed by a flexible wall constituting the outlet for the ultra-sonic waves.
  • Fig. 6 represents diagrammatically an, ultra-sonic wave transducer constructed, according to the invention, in the form of two coaxial paraboloids having the same focus, the transducer being shown schematically in section on a plane containing the common axis.
  • the transducer comprises a piczo-eiectric crystal C emitting ultra-sonic waves, a container E intended to enclose the liquid conductive to these waves and comprising two paraboloids Pr and P2 and a flexible wall P for pressing upon the surface of a body to be examined or treated with the said waves.
  • outlet area of the transducer it is possible to select the outlet area of the transducer as small as may be desired by adopting suitable values for the principal parameters and the axial lengths of the two para boloids, or of the two parabolae obtained by taking a Section of the paraboloids on a plane passing through their common axis.
  • the suffix 1 relates to the larger parabola P1 and the sufl'ix 2 to the smaller parabola P2.
  • the relations adopted might bez tion.
  • it is satisfactory to approximate this ideal form by simpler surfaces,.as, for ext'o-conical portions are approximationsof the ideal biparaboloidal profile such as that shown in Fig. '6 andhave been found to produce good results while being easier to manufacture;
  • a hollow housing comprising two frusto-conical portions having equal cross-section at their small ends and unequal cross-section at their large end, said frusto-conical portions being disposed coaxially with their small ends in communication with one another said housing being filled with a Wave conducting medium, wave-emitting means closing the larger end of the frusto-conical portion of larger cross-section and a flexible wall closing the opposite end of the housing, whereby waves from said emitting means are transmitted by said wave conducting medium and are in part reflected by said annular wall with a twofold reflection, once before and once after said section of reduced cross-sectional area so as to be focused into a beam of higher concentration and better directivity at the smaller end of said housing.
  • a hollow hous ing comprising two hollow paraboloids disposed coaxially with one another and with their foci substantially coinciding and a neck portion connecting said paraboloids, said housing being filled with a wave conducting medium, wave-emitting means at one end of the housing and a flexible wall closing the opposite end of the housing, whereby waves from said emitting means are transmitted by said wave conducting medium and are in part reflected by said annular wall with a twofold reflection, once before and once after said section of reduced crosssectional area so, as to be focused into a beam of higher concentration and better directivity at the smaller end of said housing.
  • a hollow housing comprising two hollow paraboloid portions disposed coaxially with one another and with their foci substantially coinciding and a neck portion connecting said paraboloid portions, one of said paraboloid portions having a base of larger cross-section than the other, said housing being filled with a wave conducting medium wave-emitting means at the base of larger cross-section and a flexible wall closing the opposite end of the housing, whereby waves from said emitting means are transmitted by said wave conducting medium and are in part reflected by said annular wall with a twofold reflection, once before and once after said section of reduced cross-sectional area so as to be focused into a beam of higher concentration and better directivity at thesmaller end of said housing.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Multimedia (AREA)
  • Transducers For Ultrasonic Waves (AREA)
  • Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
US277330A 1951-03-19 1952-03-18 Ultra-sonic wave transducers Expired - Lifetime US2779880A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
FR1034141D FR1034141A (fr) 1951-03-19 1951-03-19 Transducteur ultrasonore émetteur de faible section de sortie et source d'un faisceau peu divergent
CH304763D CH304763A (fr) 1951-03-19 1952-03-04 Transducteur ultrasonore à milieu de liaison liquide.
GB6654/52A GB700151A (en) 1951-03-19 1952-03-14 Improvements in ultra-sonic wave transducers
US277330A US2779880A (en) 1951-03-19 1952-03-18 Ultra-sonic wave transducers
FR64065D FR64065E (fr) 1951-03-19 1953-08-04 Transducteur ultra-sonore émetteur de faible section de sortie et source d'un faisceau peu divergent
FR64064D FR64064E (fr) 1951-03-19 1953-08-04 Transducteur ultra-sonore émetteur de faible section de sortie et source d'un faisceau peu divergent

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR1034141T 1951-03-19
US277330A US2779880A (en) 1951-03-19 1952-03-18 Ultra-sonic wave transducers

Publications (1)

Publication Number Publication Date
US2779880A true US2779880A (en) 1957-01-29

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US277330A Expired - Lifetime US2779880A (en) 1951-03-19 1952-03-18 Ultra-sonic wave transducers

Country Status (4)

Country Link
US (1) US2779880A (fr)
CH (1) CH304763A (fr)
FR (3) FR1034141A (fr)
GB (1) GB700151A (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3035491A (en) * 1957-08-02 1962-05-22 Fairchild Camera Instr Co Ultrasonic light modulator cell assembly
US3175406A (en) * 1963-03-25 1965-03-30 Bell Telephone Labor Inc Mechanical amplitude transformer
US3964308A (en) * 1973-09-04 1976-06-22 Scarpa Laboratories, Inc. Ultrasonic flowmeter
US4016751A (en) * 1973-09-13 1977-04-12 The Commonwealth Of Australia Care Of The Department Of Health Ultrasonic beam forming technique
US20080127732A1 (en) * 2006-11-28 2008-06-05 Fbs, Inc. Non-destructive examination apparatus and method for guided waves
US8296084B1 (en) * 2012-01-17 2012-10-23 Robert Hickling Non-contact, focused, ultrasonic probes for vibrometry, gauging, condition monitoring and feedback control of robots

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1207681B (de) * 1962-06-22 1965-12-23 Lehfeldt & Co G M B H Dr Ultraschall-Behandlungsvorrichtung fuer lange oder grossflaechige Gegenstaende

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US250331A (en) * 1881-12-06 Filter
FR745611A (fr) * 1933-05-13
US2532507A (en) * 1945-08-13 1950-12-05 Acec Feeler for elastic waves
US2565725A (en) * 1946-05-21 1951-08-28 Sperry Prod Inc Supersonic inspection for flaws lying near the surface of a part
US2632634A (en) * 1950-09-23 1953-03-24 Brush Dev Co Electroacoustic device
US2668529A (en) * 1948-10-01 1954-02-09 Theodor F Huter Device for transmitting ultrasound energy

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US250331A (en) * 1881-12-06 Filter
FR745611A (fr) * 1933-05-13
US2532507A (en) * 1945-08-13 1950-12-05 Acec Feeler for elastic waves
US2565725A (en) * 1946-05-21 1951-08-28 Sperry Prod Inc Supersonic inspection for flaws lying near the surface of a part
US2668529A (en) * 1948-10-01 1954-02-09 Theodor F Huter Device for transmitting ultrasound energy
US2632634A (en) * 1950-09-23 1953-03-24 Brush Dev Co Electroacoustic device

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3035491A (en) * 1957-08-02 1962-05-22 Fairchild Camera Instr Co Ultrasonic light modulator cell assembly
US3175406A (en) * 1963-03-25 1965-03-30 Bell Telephone Labor Inc Mechanical amplitude transformer
US3964308A (en) * 1973-09-04 1976-06-22 Scarpa Laboratories, Inc. Ultrasonic flowmeter
US4016751A (en) * 1973-09-13 1977-04-12 The Commonwealth Of Australia Care Of The Department Of Health Ultrasonic beam forming technique
US20080127732A1 (en) * 2006-11-28 2008-06-05 Fbs, Inc. Non-destructive examination apparatus and method for guided waves
US7938008B2 (en) * 2006-11-28 2011-05-10 Fbs, Inc. Non-destructive examination apparatus and method for guided waves
US8296084B1 (en) * 2012-01-17 2012-10-23 Robert Hickling Non-contact, focused, ultrasonic probes for vibrometry, gauging, condition monitoring and feedback control of robots

Also Published As

Publication number Publication date
FR1034141A (fr) 1953-07-20
GB700151A (en) 1953-11-25
CH304763A (fr) 1955-01-31
FR64065E (fr) 1955-10-20
FR64064E (fr) 1955-10-20

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