Patent US4613784A successfully refreshed from Google Patents.
US4613784A
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Transversely reinforced piezoelectric composites
Assignee: United States Department of the Navy
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Filing: 1984-12-21
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Granted: 1986-09-23
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Expires: 2004-12-21
Abstract
Abstract Piezoelectric PZT-polymer composites of 1-3 and 1-3-0 connectivity are transversely reinforced with glass fibers to increase the hydrostatic piezoelectric charge and voltage coefficients ( &upbar& dh and &upbar& gh) for possible use in hydrophone applications. These composites consisted of a foamed (with porosity) or non-foamed (no porosity) polymer matrix with PZT rods aligned parallel to the poling direction and glass fibers in the remaining two transverse directions. Because of the small percentage of PZT required, these composites have densities near that of water, and much lower dielectric constants than solid PZT, resulting in large increases in the hydrostatic piezoelectric voltage coefficient &upbar& gh. By increasing the &upbar& dh and &upbar& gh coefficients, the &upbar& dh &upbar& gh product, used as the figure of merit, is greatly enhanced.
Inventors
- 👤 Michael J. Haun
- 👤 Robert E. Newnham
- 👤 Walter A. Schulze
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 21:53
CPC Classifications
H; H10; H10N; H10N30/00; H10N30/80; H10N30/85; H10N30/852; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24058; Y10T428/24124; Y10T428/249921; Y10T428/31504; Y10T428/31511; Y10T428/31525; Y10T428/31551
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
50 words
A PZT-glass-polymer composite material of 1-2-3 connectivity which comprises: a matrix of a polymer; a plurality of generally parallel PZT-rods aligned in the direction of a poling electric field secured in said matrix of the polymer; means for electrically poling said plurality of PZT-rods in said matrix of the polymer;
Claim 2
Dependent Claim
50 words
A PZT-glass-polymer composite material of 1-2-3 connectivity which comprises: a matrix of a polymer; a plurality of generally parallel PZT-rods aligned in the direction of a poling electric field secured in said matrix of the polymer; means for electrically poling said plurality of PZT-rods in said matrix of the polymer;
Claim 3
Dependent Claim
46 words
a first plurality of glass-fibers aligned in a direction perpendicular to said plurality of PZT-rods; and a second plurality of glass-fibers aligned in a direction perpendicular both to the direction of said plurality of PZT-rods and to the direction of said first plurality of glass fibers.
Claim 4
Dependent Claim
46 words
a first plurality of glass-fibers aligned in a direction perpendicular to said plurality of PZT-rods; and a second plurality of glass-fibers aligned in a direction perpendicular both to the direction of said plurality of PZT-rods and to the direction of said first plurality of glass fibers.
Claim 5
Dependent Claim
25 words
The PZT-glass-polymer composite material of claim 1 wherein said composite material is in the form of a foam and has a connectivity pattern of 1-2-3-0.
Claim 6
Dependent Claim
17 words
The PZT-glass-polymer composite material of claim 1 wherein said plurality of PZT-rods are dispersed in said polymer.
Claim 7
Dependent Claim
18 words
The PZT-glass-polymer composite material of claim 3 wherein said first plurality of glass-fibers are dispersed in said polymer.
Claim 8
Dependent Claim
19 words
The PZT-glass-polymer composite material of claim 4 wherein said second plurality of glass fibers are dispersed in said polymer.
Claim 9
Dependent Claim
13 words
The PZT-glass-polymer composite material of claim 1 wherein said polymer is an epoxy.
Claim 10
Dependent Claim
13 words
The PZT-glass-polymer composite material of claim 1 wherein said polymer is a polyurethane.
Claim 11
Dependent Claim
24 words
The PZT-glass-polymer composite material of claim 1 wherein said first plurality of glass fibers and second plurality of glass fibers are made of E-glass.
Claim 12
Dependent Claim
21 words
The PZT-glass-polymer composite material wherein said plurality of PZT-rods are of variable diameter for obtaining desired characteristics of said composite material.
Claim 13
Dependent Claim
21 words
The PZT-glass-polymer composite material wherein said plurality of PZT-rods are of variable diameter for obtaining desired characteristics of said composite material.
Claim 14
Dependent Claim
29 words
The PZT-glass-polymer composite material wherein said first plurality of glass-fibers and said second plurality of glass fibers are of variable diameter for obtaining desired characteristics of said composite material.
Claim 15
Dependent Claim
29 words
The PZT-glass-polymer composite material wherein said first plurality of glass-fibers and said second plurality of glass fibers are of variable diameter for obtaining desired characteristics of said composite material.
References Cited (Backward Citations)
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US4412148A
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US4390583A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1989-09-22 | 1990-03-24 | 1990-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-09-22 | 1994-03-24 | 1994-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-09-22 | 1998-03-24 | 1998-09-23 | $7700.00 | Window Closed / Lapsed |