US3846744A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shock hardened transducer
Assignee: United States Department of the Navy
•
Filing: 1973-05-17
•
Granted: 1974-11-05
•
Expires: 1993-05-17
Abstract
Abstract A transducer for use underwater and capable of surviving high shock forces often sustained by ships, submarines, and unretarded air delivery weapons. A ring-shaped piezoelectric ceramic active element is tightly wound with fiberglass and potted to obtain compressive hoop stresses on the ceramic and mounted in axial compression on a transducer base for attachment to a vehicle.
Inventors
- 👤 B Harvey
- 👤 N Renna
- 👤 T Madison
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:56
CPC Classifications
B; B06; B06B; B06B1/00; B06B1/02; B06B1/06; B06B1/0644; B06B1/0655
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
106 words
A shock hardened transducer for use as an underwater hydrophone comprising: a tubular piezoelectric ceramic element; an electrode deposited over each of the inner and outer cyclindrical surfaces of said ceramic element; wrap means tightly encompassing the outer cylindrical surface of said ceramic element for producing a compressive hoop prestress; mounting means contacting the ends of said ceramic element for producing a compressive axial prestress, including a base having a tubular collar with an externally threaded end, and a stress-nut engaging said threaded end; compliant rings interposed between said mounting means and each end of said ceramic element; and potting compound completely surrounding said ceramic element.
Claim 2
Dependent Claim
106 words
A shock hardened transducer for use as an underwater hydrophone comprising: a tubular piezoelectric ceramic element; an electrode deposited over each of the inner and outer cyclindrical surfaces of said ceramic element; wrap means tightly encompassing the outer cylindrical surface of said ceramic element for producing a compressive hoop prestress; mounting means contacting the ends of said ceramic element for producing a compressive axial prestress, including a base having a tubular collar with an externally threaded end, and a stress-nut engaging said threaded end; compliant rings interposed between said mounting means and each end of said ceramic element; and potting compound completely surrounding said ceramic element.
Claim 3
Dependent Claim
27 words
The shock hardened transducer of claim 1 wherein said wrap means comprises a fiberglass filamentary thread coated with an adhesive, wound under tension on said ceramic element.
Claim 4
Dependent Claim
44 words
The shock hardened transducer of claim 2, wherein said compliant rings are further defined as a washer-shaped ring having a plurality of teeth projecting from one face thereof, said teeth contacting the ends of said ceramic element adjacent the inner and outer cylindrical surfaces.
Claim 5
Dependent Claim
32 words
The shock hardened transducer of claim 3 wherein said compliant rings are composed of metal and an insulator ring is interposed between said compliant rings and the ends of said ceramic element.
Claim 6
Dependent Claim
16 words
The shock hardened transducer of claim 4 wherein said piezoelectric ceramic element is composed of leadzirconate-titanate.
Claim 7
Dependent Claim
22 words
The shock hardened transducer of claim 4 wherein said electrodes are a noble metal coated on the inner and outer cylindrical surfaces.
Claim 8
Dependent Claim
19 words
The shock hardened transducer of claim 4 further comprising a resonant cavity formed within said tubular piezoelectric ceramic element.
References Cited (Backward Citations)
US2284088A
Cited
US2880404A
Cited
US3178681A
Cited
US3262093A
Cited
US3263208A
Cited
US3489994A
Cited
US3706967A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-04 | 1978-05-06 | 1978-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-04 | 1982-05-06 | 1982-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-04 | 1986-05-06 | 1986-11-05 | $7700.00 | Window Closed / Lapsed |