Patent US4420707A successfully refreshed from Google Patents.
US4420707A
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Backing for ultrasonic transducer crystal
Assignee: STAVELEY INSTRUMENTS Inc 421 NORTH QUAY STREET KENNEWICK WA 99336 A CORP OF WA
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Filing: 1982-08-09
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Granted: 1983-12-13
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Expires: 2002-08-09
Abstract
Abstract A disk of porous sintered metal is employed as the backing material for the piezoelectric crystal in an ultrasonic transducer.
Inventors
- 👤 Howard E. VanValkenburg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:51
CPC Classifications
G; G10; G10K; G10K11/00; G10K11/002; B; B06; B06B; B06B1/00; B06B1/02; B06B1/06; B06B1/0644; B06B1/0662; B06B1/0681
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
50 words
An electroacoustic transducer for ultrasonic inspection systems and the like which comprises: a piezoelectric element having front and back faces; and a rigid plate in intimate contact with the back face of the crystal having high ultrasonic energy attenuation characteristics, said plate being formed substantially solely of porous sintered metal.
Claim 2
Dependent Claim
50 words
An electroacoustic transducer for ultrasonic inspection systems and the like which comprises: a piezoelectric element having front and back faces; and a rigid plate in intimate contact with the back face of the crystal having high ultrasonic energy attenuation characteristics, said plate being formed substantially solely of porous sintered metal.
Claim 3
Dependent Claim
16 words
The transducer of claim 1 wherein said rigid plate makes electrical contact with said back face.
Claim 4
Dependent Claim
13 words
The transducer of claim 1 or 2 wherein said metal is stainless steel.
Claim 5
Dependent Claim
13 words
The transducer of claim 1 or 2 wherein said plate is a disk.
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) | 1986-12-12 | 1987-06-13 | 1987-12-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-12 | 1991-06-13 | 1991-12-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-12 | 1995-06-13 | 1995-12-13 | $7700.00 | Window Closed / Lapsed |