Patent US4991151A successfully refreshed from Google Patents.
US4381470A
Expired / Lapsed
US
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Stratified particle absorber
Assignee: HP Inc
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Filing: 1980-12-24
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Granted: 1983-04-26
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Expires: 2000-12-24
Abstract
Abstract The base for an array of piezoelectric crystals contains tungsten particles that are compression-molded in a binder, the size of the particles at and near the surface on which the crystals are mounted being smaller than the size of the particles remote from the surface.
Inventors
- 👤 Jerry G. Leach
- 👤 James T. Fearnside
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:19
CPC Classifications
G; G10; G10K; G10K11/00; G10K11/002; G10K11/16; G10K11/162; G10K11/165
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
109 words
A transducer, comprising an acoustic energy absorbing base, an array of piezoelectric crystals mounted in spaced parallel relationship on said base, there being cuts in said base aligned with the spaces between said crystals, said base having been molded from a mixture of high acoustic impedance particles of different sizes and a binder for the particles, the portion of the particles of a smaller size decreasing in a direction away from the interface of said base and said array of crystals, but the density of the particles by weight being the same throughout the base so as to have an acoustic impedance approximately equal to that of said crystals.
Claim 2
Dependent Claim
109 words
A transducer, comprising an acoustic energy absorbing base, an array of piezoelectric crystals mounted in spaced parallel relationship on said base, there being cuts in said base aligned with the spaces between said crystals, said base having been molded from a mixture of high acoustic impedance particles of different sizes and a binder for the particles, the portion of the particles of a smaller size decreasing in a direction away from the interface of said base and said array of crystals, but the density of the particles by weight being the same throughout the base so as to have an acoustic impedance approximately equal to that of said crystals.
Claim 3
Dependent Claim
16 words
A transducer as set forth in claim 1 wherein said high acoustic impedance particles are tungsten.
Claim 4
Dependent Claim
25 words
A transducer as set forth in claim 2 wherein a portion of said base adjacent said array of crystals is comprised of a thermoplastic polymer.
References Cited (Backward Citations)
US3663842A
Cited
US4101795A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-04-25 | 1986-10-25 | 1987-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-04-25 | 1990-10-25 | 1991-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-04-25 | 1994-10-25 | 1995-04-26 | $7700.00 | Window Closed / Lapsed |