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US4679178A Expired / Lapsed US ⏱️ 0.0 years remaining

Arrangement in hydrophone

Assignee: Westerngeco AS
•
Filing: 1985-09-19
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Granted: 1987-07-07
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Expires: 2005-09-19
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Abstract

Abstract An arrangement in a piezoelectric hydrophone that is provided with a protective outer housing enveloping a waterproof closed casing (2). Said casing is provided with two mutually opposed and parallel diaphragm wafers (3) on the insides of which piezoelectric crystals (4) being metal coated on their outsides are respectively attached. A connecting wire is extended from said case through its hollow central portion (6). Said central portion (6) is formed by at least two ceramic elements (7) joined along a plane parallel with the diaphragm wafers and provided with a metalization (11) in the mutual contact areas (9, 10). In the cavities (12) respectively of the two elements (7) stiffening ceramic disks (8) are provided and attached to the elements (7) by the aid of a matching projection (13). The inward facing poles of the piezoelectric crystals are conductively connected with the metalization in the contact plane of the elements, and an additional wire (5) is provided from the metalization (11) on the outside. The poles facing outward of said crystals are connected via said diaphragm wafers (3) on the outside of the casing (2). The ceramic material used is Al 2 O 3 having a degree of purity of more than 85%.

Inventors

  • 👤 Eigil Larsen
  • 👤 Eldar Lien
  • 👤 Clive Snook

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 01:04
CPC Classifications
B; B06; B06B; B06B1/00; B06B1/02; B06B1/06; B06B1/0644; B06B1/0662; B06B1/0666

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 174 words
An arrangement in a piezoelectric hydrophone having a protective outer housing, in which a water-proof casing is provided comprising two mutually opposed and parallel diaphragm wafers on inner surfaces on which piezoelectric crystals with poles are secured and are coated on their outer surfaces, and where connecting wires extend from the casing through a hollow central portion, and wherein (a) the central portion of the casing comprises at least two joined ceramic elements, extending in a plane parallel with the diaphragm wafers and being provided with a metalization in areas of mutual contact, (b) in the cavity of the two joined ceramic elements respectively, a stiffening ceramic plate is inserted and secured to said two joined ceramic elements by matching projections, and (c) the poles of the piezoelectric crystals facing inward are conductively connected to the metalization in the connecting plane of the two joined ceramic elements with an additional conductive connection from the metalization externally, whereas the poles of the piezoelectric crystals facing outward are joined outside the casing via said diaphragm wafers.
Claim 2
Dependent Claim 174 words
An arrangement in a piezoelectric hydrophone having a protective outer housing, in which a water-proof casing is provided comprising two mutually opposed and parallel diaphragm wafers on inner surfaces on which piezoelectric crystals with poles are secured and are coated on their outer surfaces, and where connecting wires extend from the casing through a hollow central portion, and wherein (a) the central portion of the casing comprises at least two joined ceramic elements, extending in a plane parallel with the diaphragm wafers and being provided with a metalization in areas of mutual contact, (b) in the cavity of the two joined ceramic elements respectively, a stiffening ceramic plate is inserted and secured to said two joined ceramic elements by matching projections, and (c) the poles of the piezoelectric crystals facing inward are conductively connected to the metalization in the connecting plane of the two joined ceramic elements with an additional conductive connection from the metalization externally, whereas the poles of the piezoelectric crystals facing outward are joined outside the casing via said diaphragm wafers.
Claim 3
Dependent Claim 30 words
An arrangement as claimed in claim 1, wherein Al 2 O 3 having a degree of purity of more than 85%, preferably approximately 96% is used as a ceramic material.
Claim 4
Dependent Claim 32 words
An arrangement as claimed in claim 1, wherein the two joined ceramic elements are rounded at both sides in the joint plane and that the metalization is applied along the rounded portions.
Claim 5
Dependent Claim 29 words
An arrangement as claimed in claim 1, wherein the gap formed on the outside by rounded portions of the two joined ceramic elements is filled with a soldering material.
Claim 6
Dependent Claim 52 words
An arrangement as stated in claim 1, wherein the ceramic plate has a through hole near its circumference and on the surface averted from the crystal is provided with a metalization that is by the aid of a soldering material electrically connected with an adjacent metalization on the two joined ceramic element.
Claim 7
Dependent Claim 22 words
An arrangement as claimed in claim 1, wherein the two joined ceramic elements, the ceramic plate, and the diaphragm wafer are circular.
Claim 8
Dependent Claim 20 words
An arrangement as claimed in claim 1, wherein the housing is an elliptical cylinder, holding the case via a lining.

References Cited (Backward Citations)

US3255431A Cited
US3660809A Cited
US3832762A Cited
US3970878A Cited
US4336639A Cited
US4517664A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-07-06 1991-01-05 1991-07-07 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-07-06 1995-01-05 1995-07-07 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-07-06 1999-01-05 1999-07-07 $7700.00 Window Closed / Lapsed

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