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Patent US3706967A successfully refreshed from Google Patents.
US3706967A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Underwater acoustic projector
Assignee: United States Department of the Navy
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Filing: 1971-01-21
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Granted: 1972-12-19
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Expires: 1991-01-21
Abstract
Abstract A high efficiency, broadband acoustic projector for deep water applications in excess of twelve thousand feet. The projector comprises an active element consisting of a plurality of piezoelectric staves electrically connected in series. The staves are physically arranged in a cylindrical assembly prestressed in a fibrous glass wrapping, and installed in an annular, acoustically transparent, neoprene boot. Air-exhausted oil fills the boot to completely immerse the active element and thereby couple the radiated energy thereof to the surrounding water. The center cavity of the projector is open at both ends for freeflooding. Broadband response is achieved by close-coupling the active element''s cavity and hoop resonances whereby they reinforce each other across a broad range of operating frequencies.
Inventors
- 👤 Nicholas Renna Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 07:55
CPC Classifications
B; B06; B06B; B06B1/00; B06B1/02; B06B1/06; B06B1/0644; B06B1/0655
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
63 words
An underwater acoustic projector, comprising: an acoustically transparent annular boot having concentric walls sealingly closed at one end to form an annular trough around a cylindrical open-ended cavity; a cylindrical piezoelectric element spatially positioned within the trough; an annular cover mounted on the otheR end of said boot sealingly enclosing the trough; and castor oil completely filling the unoccupied space in the trough.
Claim 2
Dependent Claim
63 words
An underwater acoustic projector, comprising: an acoustically transparent annular boot having concentric walls sealingly closed at one end to form an annular trough around a cylindrical open-ended cavity; a cylindrical piezoelectric element spatially positioned within the trough; an annular cover mounted on the otheR end of said boot sealingly enclosing the trough; and castor oil completely filling the unoccupied space in the trough.
Claim 3
Dependent Claim
36 words
An underwater acoustic projector according to claim 1 further comprising: said element including a circular array of lead zirconate lead titanate staves bonded together and an outside fiberglass covering inducing a hoop prestress in said element.
Claim 4
Dependent Claim
33 words
An underwater acoustic projector according to claim 2 further comprising: said element having a h/a ratio equal to or less than 1.0, where h length of element, and a inside radius of element.
Claim 5
Dependent Claim
30 words
An underwater acoustic projector according to claim 3 further comprising: said element having a t/d ratio of substantially 0.04 where t thickness of element, and d outside diameter of element.
Claim 6
Dependent Claim
43 words
An underwater acoustic projector according to claim 4 further comprising: said boot being formed of neoprene and including a plurality of circumferentially spaced support pads at the closed end of said boot formed to receive confronting portions of one end of said element.
Claim 7
Dependent Claim
42 words
An underwater acoustic projector according to claim 5 further comprising: said cover being formed of neoprene and including a plurality of circumferentially spaced support pads extending into said boot and formed to receive confronting portions of the other end of said element.
Claim 8
Dependent Claim
31 words
An underwater acoustic projector according to claim 6 further comprising: said cover further including openings for filling and venting the space within said boot, and plugs sealingly inserted within said openings.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-12-19 | 1976-06-19 | 1976-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-19 | 1980-06-19 | 1980-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-19 | 1984-06-19 | 1984-12-19 | $7700.00 | Window Closed / Lapsed |