US3728562A
Expired / Lapsed
US
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Electroacoustic transducer having transducing element supporting means
Assignee: AT&T Inc
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Filing: 1971-10-18
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Granted: 1973-04-17
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Expires: 1991-10-18
Abstract
Abstract An electromechanical transducer element is supported within a transducer housing by a trilaminar diaphragm comprising a layer of viscoelastic material sandwiched between a pair of rigid plates. By locating the neutral bending plane of the composite diaphragm-element structure in the center layer of viscoelastic material, where shear stresses are maximal, the resultant shear deformation in the viscoelastic material advantageously dissipates vibratory energy. This provides a means of reducing undesirable peaks in the transducer''s frequency response and results in a more uniform response characteristic.
Inventors
- 👤 R Herson
- 👤 S Kitsopoulos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:35
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/22; H04R17/00
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
92 words
An electroacoustic transducer comprising, an electromechanical transducing element, a housing defining an internal chamber for containing said element, means for supporting said element within said chamber, said supporting means including a trilaminar planar member having a top layer, a middle layer and a bottom layer, said top and bottom layers comprising a rigid material and said middle layer comprising a viscoelastic material, and means for attaching said element to said planar member to form a composite structure, wherein the neutral bending plane of said composite structure is located in said middle layer.
Claim 2
Dependent Claim
92 words
An electroacoustic transducer comprising, an electromechanical transducing element, a housing defining an internal chamber for containing said element, means for supporting said element within said chamber, said supporting means including a trilaminar planar member having a top layer, a middle layer and a bottom layer, said top and bottom layers comprising a rigid material and said middle layer comprising a viscoelastic material, and means for attaching said element to said planar member to form a composite structure, wherein the neutral bending plane of said composite structure is located in said middle layer.
Claim 3
Dependent Claim
16 words
The invention defined in claim 1 wherein said transducing element includes a polarizable ferroelectric ceramic material.
Claim 4
Dependent Claim
26 words
The invention defined in claim 2 wherein said ceramic material is selected from the group consisting of barium titanate, lead titanate-lead zirconate, and sodium potassium niobate.
Claim 5
Dependent Claim
26 words
The invention defined in claim 3 wherein said viscoelastic material includes a lightly cross-linked, long chained elastomer having a shear loss factor in excess of 0.2.
Claim 6
Dependent Claim
13 words
The invention defined in claim 4 wherein said rigid material includes a metal.
Claim 7
Dependent Claim
11 words
The invention defined in claim 5 wherein said metal includes aluminum.
Claim 8
Dependent Claim
96 words
An electroacoustic transducer comprising an electromechanical transducing element, a housing defining an internal chamber for containing said element, and means for supporting said element within said chamber, characterized in that said supporting means includes a trilaminar planar member having a top layer, a middle layer, and a bottom layer, said top and bottom layers consisting essentially of a rigid material and said middle layer consisting essentially of a visco-elastic material, and further characterized in that said transducing element and said supporting means form a composite structure having a neutral bending plane located in said middle layer.
Claim 9
Dependent Claim
96 words
An electroacoustic transducer comprising an electromechanical transducing element, a housing defining an internal chamber for containing said element, and means for supporting said element within said chamber, characterized in that said supporting means includes a trilaminar planar member having a top layer, a middle layer, and a bottom layer, said top and bottom layers consisting essentially of a rigid material and said middle layer consisting essentially of a visco-elastic material, and further characterized in that said transducing element and said supporting means form a composite structure having a neutral bending plane located in said middle layer.
Claim 10
Dependent Claim
24 words
The invention defined in claim 7 wherein said rigid material includes a metal and said viscoelastic material includes a lightly cross-linked, long chained elastomer.
Claim 11
Dependent Claim
21 words
The invention defined in cLaim 8 wherein said elastomer includes a polyester-based polymer having a shear loss factor greater than 0.2.
Claim 12
Dependent Claim
110 words
An electroacoustic transducer comprising, a piezoelectric ceramic transducing element, a housing defining an internal chamber for containing said element, means for supporting said element within said chamber, means for attaching said supporting means to said housing within said chamber, and means for attaching said element to said supporting means to form a composite structure having a neutral bending plane, characterized in that said supporting means includes a trilaminar planar member having a top layer, a middle layer, and a bottom layer, said top and bottom layers comprising a metal and said middle layer comprising a viscoelastic material, and further characterized in that said plane is located within said middle layer.
Claim 13
Dependent Claim
110 words
An electroacoustic transducer comprising, a piezoelectric ceramic transducing element, a housing defining an internal chamber for containing said element, means for supporting said element within said chamber, means for attaching said supporting means to said housing within said chamber, and means for attaching said element to said supporting means to form a composite structure having a neutral bending plane, characterized in that said supporting means includes a trilaminar planar member having a top layer, a middle layer, and a bottom layer, said top and bottom layers comprising a metal and said middle layer comprising a viscoelastic material, and further characterized in that said plane is located within said middle layer.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-16 | 1976-10-16 | 1977-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-16 | 1980-10-16 | 1981-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-16 | 1984-10-16 | 1985-04-17 | $7700.00 | Window Closed / Lapsed |