US3631383A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Piezoelectric transducer configuration
Assignee: Bendix Corp
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Filing: 1969-07-25
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Granted: 1971-12-28
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Expires: 1989-07-25
Abstract
Abstract Piezoelectric transducer elements are polarized to vibrate in a number of different planes such as longitudinally, radially, or axially. Polarized flat disk or bar transducers have been severely limited in power-handling capacity because of the inherent weakness of the usual piezoelectric materials in tension. Applicant has found that flexural disk-type elements as well as ''''bender bar'''' types of transducers, all of which require that the piezoelectric elements be stressed in tension, gain very substantially in power-handling capacity when a thin layer of material, such as a metal plate, is bonded to the face exposed to tensile forces. Alternately, a laminate layer of glass epoxy was also found effective to improve the power handling capabilities of the transducers, and this has been found especially useful where an electrical insulating layer is required.
Inventors
- 👤 Gene Zilinskas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:19
CPC Classifications
H; H04; H04R; H04R17/00; Y; Y10; Y10T; Y10T29/00; Y10T29/42; Y10T29/49; Y10T29/49002; Y10T29/49005
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
54 words
A transducer as set forth in claim 1 wherein said member and said backing member comprise disks, said backing member being of substantial thickness and being bonded to said member and said member being polarized and mounted such that said disks vibrate in flexure as a unit parallel to the axis of said transducer.
Claim 2
Dependent Claim
67 words
A transducer as set forth in claim 2 wherein two pairs of said disks are arranged back to back and are spaced from each other by means providing an airspace between said backing members, and said backing members are electrically connected to adjacent electrodes to form one side of an electrical circuit and the remaining electrodes are connected together to form the opposite side of said circuit.
Claim 3
Dependent Claim
69 words
A transducer as set forth in claim 1 wherein a plurality of individual flexural segments of piezoelectric material are alternately poled and mechanically positioned to form a bender bar, said segments are assembled in layers such that each layer acts as a backing member for the other, and one of said layers is bonded to each exposed face of said bar, said layers being formed of high-strength insulating material.
Claim 4
Dependent Claim
27 words
A transducer as set forth in claim 4 wherein each of said layers also includes a thin metal strip separated from said segments by said insulating material.
Claim 5
Dependent Claim
119 words
An underwater transducer for converting electrical eneRgy to acoustic energy and operative in the bending mode for projecting said acoustic energy into the surrounding water comprising first and second thickness polarized disks of piezoelectric material including electrode means, first and second disk-shaped metal backing plates bonded to one face of said first and second piezoelectric disks respectively, a radially compliant spacer member fastened to said first and second backing plates such that an airspace is confined between said backing plates, and a layer of material of substantially higher tensile strength than said piezoelectric material bonded to each opposite face of said disks, said layer being sufficiently thin that it has negligible effect on the frequency characteristics of said transducer.
Claim 6
Dependent Claim
19 words
A transducer as set forth in claim 6 wherein each said layer of material comprises a thin metal disk.
Claim 7
Dependent Claim
22 words
A transducer as set forth in claim 6 wherein said metal backing plates are substantially the same thickness as said piezoelectric disks.
Claim 8
Independent Claim
107 words
A method of making disk-type transducers for projecting acoustic energy into the surrounding water comprising the steps of forming a first disk of piezoelectric material polarized such that when energized with an electrical alternating current signal it tends to vibrate perpendicular to its faces, forming a backing member comprising a second disk of substantial stiffness and of essentially the same dimensions as said first disk, bonding said first disk to said second disk, forming a very thin disk of material having substantially greater strength in tension than said piezoelectric material, and bonding said thin disk to the opposite side of said piezoelectric material from said second disk.
Claim 9
Independent Claim
67 words
A method of making piezoelectric transducers of the type which, when energized, have at least one surface stressed in tension comprising forming said transducer of piezoelectric material to the desired shape and connecting electrodes thereto, bonding a backing member of substantial stiffness to another surface of said transducer, and bonding a thin layer of material having substantial strength in tension to said one surface of said transducer.
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) | 1974-12-27 | 1975-06-28 | 1975-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-27 | 1979-06-28 | 1979-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-27 | 1983-06-28 | 1983-12-28 | $7700.00 | Window Closed / Lapsed |