US3753218A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electro-mechanical acoustic filter
Assignee: United States Department of the Navy
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Filing: 1956-09-21
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Granted: 1973-08-14
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Expires: 1976-09-21
Abstract
Abstract 1. A passive hydro-acoustic device for providing band pass filtering and detection of low frequency acoustic pressure signals transmitted through water and with said filtering occurring prior to transduction of said signals into electrical energy signals, which comprises input coupling means disposed to provide coupling of acoustic pressure signal intelligence from an external underwater sound field to the interior of said device, a fluid filled housing adapted to be closed by said input coupling means, a hydraulic tube disposed within said housing and in fluid communication with said input coupling means, means in said housing for providing a substantially enclosed air volume in hydraulic shunt relation to said input coupling means, an electrolytic detector cell for providing an electrical signal output and disposed in fluid communication with the end of said hydraulic tube remote from said input coupling means and a fluid filled chamber of substantial capacity disposed in said housing for providing said fluid communication between said hydraulic tube, said detector cell and said air volume means.
Inventors
- 👤 G Thurston
- 👤 O Hill
- 👤 H Hillery
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:33
CPC Classifications
G; G10; G10K; G10K11/00; G10K11/02; G10K11/04
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
167 words
A passive hydro-acoustic device for providing band pass filtering and detection of low frequency acoustic pressure signals transmitted through water and with said filtering occurring prior to transduction of said signals into electrical energy signals, which comprises input coupling means disposed to provide coupling of acoustic pressure signal intelligence from an external underwater sound field to the interior of said device, a fluid filled housing adapted to be closed by said input coupling means, a hydraulic tube disposed within said housing and in fluid communication with said input coupling means, means in said housing for providing a substantially enclosed air volume in hydraulic shunt relation to said input coupling means, an electrolytic detector cell for providing an electrical signal output and disposed in fluid communication with the end of said hydraulic tube remote from said input coupling means and a fluid filled chamber of substantial capacity disposed in said housing for providing said fluid communication between said hydraulic tube, said detector cell and said air volume means.
Claim 2
Dependent Claim
167 words
A passive hydro-acoustic device for providing band pass filtering and detection of low frequency acoustic pressure signals transmitted through water and with said filtering occurring prior to transduction of said signals into electrical energy signals, which comprises input coupling means disposed to provide coupling of acoustic pressure signal intelligence from an external underwater sound field to the interior of said device, a fluid filled housing adapted to be closed by said input coupling means, a hydraulic tube disposed within said housing and in fluid communication with said input coupling means, means in said housing for providing a substantially enclosed air volume in hydraulic shunt relation to said input coupling means, an electrolytic detector cell for providing an electrical signal output and disposed in fluid communication with the end of said hydraulic tube remote from said input coupling means and a fluid filled chamber of substantial capacity disposed in said housing for providing said fluid communication between said hydraulic tube, said detector cell and said air volume means.
Claim 3
Dependent Claim
86 words
In combination a housing means, a frequency selective hydro-acoustic filter comprising hydraulic capacitance inductance and hydraulic resistance elements and an electrolytic detector cell in fluid communication with said filter, and disposed in said housing, a shunt connected air capacitance chamber in said housing, said detector cell providing a series connected hydraulic capacitance, hydraulic inductance and hydraulic resistance for providing a symmetrical ''''T''''-filter configuration with respect to said air capacitance and said first named filter elements, and means for obtaining a detected electrical output from said cell.
Claim 4
Dependent Claim
86 words
In combination a housing means, a frequency selective hydro-acoustic filter comprising hydraulic capacitance inductance and hydraulic resistance elements and an electrolytic detector cell in fluid communication with said filter, and disposed in said housing, a shunt connected air capacitance chamber in said housing, said detector cell providing a series connected hydraulic capacitance, hydraulic inductance and hydraulic resistance for providing a symmetrical ''''T''''-filter configuration with respect to said air capacitance and said first named filter elements, and means for obtaining a detected electrical output from said cell.
Claim 5
Dependent Claim
170 words
A hydro-acoustic pressure signal filter of predetermined band pass and frequency attenuation characteristics for providing a desired pass and range and for use with a hydro-acoustic sensitive detector having an inherent hydraulic capacity whereby an electrical signal output may be provided, which comprises a first hydraulic capacitance member disposed in series relation with one side of the filter input, means providing hydraulic inductance and resistance in series with the output side of said capacitance member, a second hydraulic capacitance disposed in shunt relation with the output side of said hydraulic inductance and resistance, means in said detector for providing a second hydraulic-resistance and inductance in series with said first named hydraulic resistance and inductance means and connected to follow said shunt connected capacitance member, the output of said filter appearing across said detector resistance and inductance, and means connecting the capacitance of said detector in shunt with the second side of said filter and the filter output connections remote from the junction connection of said first named shunting capacitance member.
Claim 6
Dependent Claim
170 words
A hydro-acoustic pressure signal filter of predetermined band pass and frequency attenuation characteristics for providing a desired pass and range and for use with a hydro-acoustic sensitive detector having an inherent hydraulic capacity whereby an electrical signal output may be provided, which comprises a first hydraulic capacitance member disposed in series relation with one side of the filter input, means providing hydraulic inductance and resistance in series with the output side of said capacitance member, a second hydraulic capacitance disposed in shunt relation with the output side of said hydraulic inductance and resistance, means in said detector for providing a second hydraulic-resistance and inductance in series with said first named hydraulic resistance and inductance means and connected to follow said shunt connected capacitance member, the output of said filter appearing across said detector resistance and inductance, and means connecting the capacitance of said detector in shunt with the second side of said filter and the filter output connections remote from the junction connection of said first named shunting capacitance member.
Claim 7
Dependent Claim
28 words
A band pass filter and electrolytic detector of the character of claim 3 further characterized by said first hydraulic resistance and inductance means comprising a bent hydraulic tube.
References Cited (Backward Citations)
US2405179A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-13 | 1977-02-12 | 1977-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-13 | 1981-02-12 | 1981-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-13 | 1985-02-12 | 1985-08-14 | $7700.00 | Window Closed / Lapsed |