US3666979A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Focused piezoelectric transducer and method of making
Assignee: STAVELEY INSTRUMENTS Inc 421 NORTH QUAY STREET KENNEWICK WA 99336 A CORP OF WA
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Filing: 1970-06-17
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Granted: 1972-05-30
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Expires: 1990-06-17
Abstract
Abstract An apparatus and method for fabricating focused high frequency electromechanical transducers especially useful in ultrasonic inspection apparatus is disclosed. An initially flat or planar piezoelectric crystal is placed between a pair of members having mating surfaces contoured to correspond to the desired shape of the crystal. When the members are forced together the crystal is bent or otherwise formed into the desired shape.
Inventors
- 👤 Jerry T Mcelroy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:08
CPC Classifications
G; G01; G01N; G01N29/00; G01N29/22; G01N29/221; G10; G10K; G10K11/00; G10K11/18; G10K11/26; G10K11/32; Y; Y10; Y10T; Y10T29/00; Y10T29/42
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
61 words
A method of forming a focused ultrasonic transducer including the steps of: positioning a ceramic piezoelectric element that is in solid form upon a surface having a contour corresponding to the desired final shape of the transducer; forming said element while it is in said solid form around said surface into said final shape; and retainiNg said element in said shape.
Claim 2
Independent Claim
61 words
A method of forming a focused ultrasonic transducer including the steps of: positioning a ceramic piezoelectric element that is in solid form upon a surface having a contour corresponding to the desired final shape of the transducer; forming said element while it is in said solid form around said surface into said final shape; and retainiNg said element in said shape.
Claim 3
Dependent Claim
45 words
The method of claim 1 wherein the steps of forming said element into said shape creates a stress state in said element and retaining said element in said shape includes bonding said element onto a backing member and maintaining said element in the stressed state.
Claim 4
Independent Claim
104 words
A method of forming a focused electromechanical transducer including the steps of: providing a ceramic piezoelectric blank having a pair of parallel flat surfaces; polarizing said piezoelectric blank; lapping at least one of said surfaces to reduce the thickness of the blank to the desired thickness of the transducer; positioning the lapped blank on a mounting member having a surface with a contour corresponding to the desired contour of the transducer; applying an adhesive material between the surface of the mounting member and the blank; and pressing the blank against the surface of the mounting member and bonding the blank to the mounting member.
Claim 5
Independent Claim
104 words
A method of forming a focused electromechanical transducer including the steps of: providing a ceramic piezoelectric blank having a pair of parallel flat surfaces; polarizing said piezoelectric blank; lapping at least one of said surfaces to reduce the thickness of the blank to the desired thickness of the transducer; positioning the lapped blank on a mounting member having a surface with a contour corresponding to the desired contour of the transducer; applying an adhesive material between the surface of the mounting member and the blank; and pressing the blank against the surface of the mounting member and bonding the blank to the mounting member.
Claim 6
Dependent Claim
66 words
The method of claim 3 wherein the step of pressing the blank against the top surface of the mounting member includes the steps of: positioning a ram member, having a surface corresponding to the surface on the mounting member in engagement with the blank; and forcing the surface of the ram against the blank whereby the blank is forced against the surface of the mounting member.
Claim 7
Dependent Claim
95 words
The process of forming a focused piezoelectric crystal by positioning a substantially flat thin ceramic piezoelectric crystal, having first and second spaced parallel surfaces, on a mounting member having a contoured mounting surface adjacent said second crystal surface; applying an adhesive material into the area between said second crystal surface and said mounting surface; and applying pressure to said first crystal surface to force said second crystal surface into intimate engagement with said mounting surfaces, said pressure being applied for a sufficient time to allow said adhesive to hold said crystal in the bent condition.
Claim 8
Dependent Claim
95 words
The process of forming a focused piezoelectric crystal by positioning a substantially flat thin ceramic piezoelectric crystal, having first and second spaced parallel surfaces, on a mounting member having a contoured mounting surface adjacent said second crystal surface; applying an adhesive material into the area between said second crystal surface and said mounting surface; and applying pressure to said first crystal surface to force said second crystal surface into intimate engagement with said mounting surfaces, said pressure being applied for a sufficient time to allow said adhesive to hold said crystal in the bent condition.
Claim 9
Dependent Claim
65 words
The process of claim 5 wherein the last named step comprises the steps of: positioning a ram member, having a convex surface substantially matching the radius of curvature of the concave holding member surface, adjacent said first crystal surface; and forceably engaging said first crystal surface with the convex ram surface to force said second crystal surface into intimate engagement with the concave mounting surface.
Claim 10
Dependent Claim
76 words
A focused electromechanical transducer comprising: a mounting member having a curved mounting surface; a thin ceramic piezoelectric crystal having first and second spaced substantially parallel surfaces with the second surface being in intimate engagement with said curved mounting surface, said first crystal surface being in a state of compression and said second crystal surface being in a state of tension; and means for holding said second crystal surface in intimate engagement with said curved mounting surface.
Claim 11
Dependent Claim
76 words
A focused electromechanical transducer comprising: a mounting member having a curved mounting surface; a thin ceramic piezoelectric crystal having first and second spaced substantially parallel surfaces with the second surface being in intimate engagement with said curved mounting surface, said first crystal surface being in a state of compression and said second crystal surface being in a state of tension; and means for holding said second crystal surface in intimate engagement with said curved mounting surface.
Claim 12
Dependent Claim
23 words
The transducer of claim 7 wherein said stressed piezoelectric crystal is spherical in configuration having a center of curvature substantially defining a point.
Claim 13
Dependent Claim
23 words
The transducer of claim 7 wherein said stressed piezoelectric crystal is cylindrical in configuration having a center of curvature substantially defining a line.
Claim 14
Dependent Claim
23 words
The transducer of claim 7 wherein said holding means comprises a cement material interposed between said mounting surface and said second crystal surface.
Claim 15
Dependent Claim
17 words
The transducer of claim 10 further comprising a thin conductive layer positioned on said first crystal surface.
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) | 1975-05-30 | 1975-11-29 | 1976-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-30 | 1979-11-29 | 1980-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-30 | 1983-11-29 | 1984-05-30 | $7700.00 | Window Closed / Lapsed |