US4686409A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Porous adaptation layer in an ultrasonic applicator
Assignee: Siemens AG
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Filing: 1985-07-26
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Granted: 1987-08-11
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Expires: 2005-07-26
Abstract
Abstract A material is disclosed for use as an adaptation layer in ultrasonic transducer units of the type which have a piezo-ceramic transducer. The material is porous, and the acoustic impedance of the material can be adjusted (in one embodiment, to 12×10 6 kg/cm 2 s) by adjusting the porosity of the material. In preferred embodiments, the material is piezo-electric and may have a porosity gradient.
Inventors
- 👤 Hans Kaarmann
- 👤 Karl Lubitz
- 👤 Jutta Mohaupt
- 👤 Martina Vogt
- 👤 Wolfram Wersing
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 05:21
CPC Classifications
G; G10; G10K; G10K11/00; G10K11/02
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
100 words
In an ultrasonic transducer unit of the type which has a piezo-ceramic transducer, a first adaptation layer coupled to the piezo-ceramic transducer and a second adaptation layer which is coupled to the first adaptation layer and an object to be examined, the improvement comprising a first adaptation layer of a porous piezo-ceramic material with a porosity selected such that when the first adaptation layer is one quarter wavelength thick at a nominal frequency of the piezo-ceramic transducer, the first adaptation layer has an acoustic impedance which is between the acoustic impedance of the piezo-ceramic transducer and the second adaptation layer.
Claim 2
Dependent Claim
100 words
In an ultrasonic transducer unit of the type which has a piezo-ceramic transducer, a first adaptation layer coupled to the piezo-ceramic transducer and a second adaptation layer which is coupled to the first adaptation layer and an object to be examined, the improvement comprising a first adaptation layer of a porous piezo-ceramic material with a porosity selected such that when the first adaptation layer is one quarter wavelength thick at a nominal frequency of the piezo-ceramic transducer, the first adaptation layer has an acoustic impedance which is between the acoustic impedance of the piezo-ceramic transducer and the second adaptation layer.
Claim 3
Dependent Claim
20 words
The improvement of claim 1 wherein the piezo-ceramic material comprises a mixed crystal containing PbTiO 3 and PbZrO 3 .
Claim 4
Dependent Claim
15 words
The improvement of claim 2, wherein the mixed crystal further comprises an additional complex oxide.
Claim 5
Dependent Claim
17 words
The improvement of claim 3, wherein the complex oxide comprises Pb(Mg 1/3 Nb 2/3 )O 3 .
Claim 6
Dependent Claim
12 words
The improvement of claim 2, wherein the piezo-ceramic material contains a dopant.
Claim 7
Dependent Claim
26 words
The improvement of claim 1, wherein the first adaptation layer has an acoustic impedance between 11×10 6 kg/m 2 s and 13×10 6 kg/m 2 s.
Claim 8
Dependent Claim
39 words
The improvement of claim 1, wherein the acoustic impedance of the first adaptation layer varies in a manner that said acoustic impedance is at a maximum adjacent said piezo-ceramic transducer and at a minimum adjacent said second adaptation layer.
Claim 9
Dependent Claim
29 words
The improvement of claim 1, wherein said piezo-ceramic material has a thermal coefficient of expansion which is approximately matched to the thermal coefficient of expansion of the piezo-ceramic transducer.
Claim 10
Dependent Claim
20 words
The improvement of claim 1 wherein the second adaptation layer is a quarter-wavelength thick and is of a plastic material.
Claim 11
Dependent Claim
23 words
An adaptation layer for use with piezo-ceramic transducers, comprising a porous piezo-ceramic material, the porosity of the porous piezo-ceramic material having a gradient.
Claim 12
Dependent Claim
23 words
An adaptation layer for use with piezo-ceramic transducers, comprising a porous piezo-ceramic material, the porosity of the porous piezo-ceramic material having a gradient.
Claim 13
Dependent Claim
18 words
An adaptation layer for use with piezo-ceramic transducers, comprising a porous piezo-ceramic material which is a mixed crystal.
Claim 14
Dependent Claim
18 words
An adaptation layer for use with piezo-ceramic transducers, comprising a porous piezo-ceramic material which is a mixed crystal.
Claim 15
Dependent Claim
16 words
The layer of claim 10, wherein the mixed crystal comprises PbTiO 3 and PbZrO 3 .
Claim 16
Dependent Claim
14 words
The layer of claim 12, wherein the mixed crystal further comprises a complex oxide.
Claim 17
Dependent Claim
17 words
The layer of claim 13, wherein the complex oxide is Pb(Mg 1/3 Nb 2/3 )O 3 .
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-08-10 | 1991-02-09 | 1991-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-08-10 | 1995-02-09 | 1995-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-08-10 | 1999-02-09 | 1999-08-11 | $7700.00 | Window Closed / Lapsed |