US5166907A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency agile sonic transducer
Assignee: Pennsylvania Research Corp
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Filing: 1991-06-24
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Granted: 1992-11-24
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Expires: 2011-06-24
Abstract
Abstract A solid-state tunable transducer has been developed by incorporating an elastically nonlinear material, silicone rubber, into an electroacoustic transducer made from piezoelectric ceramics. The resonant frequency and mechanical Q of the transducer are tuned mechanically by applying a uniaxial compressive stress to the composite. The resonant frequency is tuned electrically by placing a piezoelectric actuator into the composite and varying the magnitude of the d.c. bias.
Inventors
- 👤 Robert E. Newnham
- 👤 Qi C. Xu
- 👤 Michael Blaszkiewicz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:15
CPC Classifications
B; B06; B06B; B06B1/00; B06B1/02; B06B1/06; B06B1/0607; B06B1/0611; B06B1/0614; H; H04; H04R; H04R17/00; H04R17/04; H04R17/08
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
71 words
A piezoelectric composite transducer assembly whose resonant frequency can be adjusted dynamically by an externally applied signal, said transducer comprising: elastic material means having an elastic modulus that is variable in accordance with an applied external force; piezoelectric means; mechanical means for holding said elastic material means and piezoelectric means in compression; and bias means connected to said piezoelectric means for stressing said piezoelectric means and electrically tuning said resonant frequency.
Claim 2
Dependent Claim
71 words
A piezoelectric composite transducer assembly whose resonant frequency can be adjusted dynamically by an externally applied signal, said transducer comprising: elastic material means having an elastic modulus that is variable in accordance with an applied external force; piezoelectric means; mechanical means for holding said elastic material means and piezoelectric means in compression; and bias means connected to said piezoelectric means for stressing said piezoelectric means and electrically tuning said resonant frequency.
Claim 3
Dependent Claim
29 words
The piezoelectric composite transducer assembly of claim 1, wherein said bias means is adapted to apply a range of voltages to said piezoelectric means to vary said electrical tuning.
Claim 4
Dependent Claim
16 words
The piezoelectric composite transducer assembly of claim 1, wherein said elastic material means includes silicone rubber.
Claim 5
Dependent Claim
33 words
The piezoelectric composite transducer assembly of claim 1 wherein said mechanical means is adjustable to vary compressive forces applied to said piezoelectric means and elastic material means, to further vary said resonant frequency.
Claim 6
Dependent Claim
26 words
The piezoelectric composite transducer of claim 1, wherein said elastic material means comprises a composite layer of elastic material rigidly bonded to an inelastic support sheet.
Claim 7
Dependent Claim
38 words
The piezoelectric composite transducer of claim 5, wherein said elastic material is silicone rubber and said support sheet includes copper, said support sheet coated with a polyimid to aid in bonding said silicon rubber to said support sheet.
Claim 8
Dependent Claim
46 words
The piezoelectric composite transducer of claim 1, wherein said piezoelectric means comprises a stack of piezoelectric ceramic wafers, and a piezoelectric transducer, said bias means connected to said stack of piezoelectric wafers to vary the compressive force exerted on said piezoelectric transducer and elastic material means.
Claim 9
Dependent Claim
43 words
The piezoelectric composite transducer of claim 7, wherein said mechanical means comprises a pair of brass blocks that sandwich said piezoelectric means and elastic material means: and means for forcing said brass blocks towards each other so as to create said compressive force.
Claim 10
Dependent Claim
22 words
The piezoelectric composite transducer of claim 8 wherein said elastic material means includes silicon rubber and said piezoelectric means comprises PZT ceramics.
References Cited (Backward Citations)
US4197478A
Cited
US4633119A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-11-24 | 1996-05-25 | 1996-11-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-11-24 | 2000-05-25 | 2000-11-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-11-24 | 2004-05-25 | 2004-11-24 | $7700.00 | Window Closed / Lapsed |