US3624565A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Toroidal filter
Assignee: Northrop Grumman Space and Mission Systems Corp
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Filing: 1969-11-03
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Granted: 1971-11-30
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Expires: 1989-11-03
Abstract
Abstract Filter assembly particularly useful as an intermediate frequency filter for FM radios, the filter including a nonmagnetic form having a plurality of toroidally wound cores positioned in spaced coaxial relation along the form, with a capacitance for each of the coils providing a tuned circuit at a predetermined frequency, the spacing between the coils being sufficiently close so that stray capacitances between the coils are sufficient for coupling the tuned circuits at the operating frequency of the filter.
Inventors
- 👤 Samuel Harris
- 👤 Edward C Horton
- 👤 Otto P Tader
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 23:36
CPC Classifications
H; H03; H03H; H03H7/00; H03H7/01; H03H7/0153; H03H7/0161; H03H7/0169; H03H7/0184; H03H7/17; H03H7/1741; H03H7/1775
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
100 words
A filter assembly comprising a magnetically shielding enclosure, a base tightly engaging said enclosure to form a bottom closure therefor, a nonmagnetic coil form supported in spaced relation to said base, a plurality of toroidally wound coils positioned coaxially in closely spaced relation along said coil form, thin nonmagnetic, dielectric spacers substantially filling the spaces between adjacent ones of said coils, and a capacitor connected to each of said coils to form a tuned circuit at a predetermined frequency, said coils being spaced sufficiently close together so that stray capacitances between the coils are sufficient to couple the tuned circuits.
Claim 2
Dependent Claim
100 words
A filter assembly comprising a magnetically shielding enclosure, a base tightly engaging said enclosure to form a bottom closure therefor, a nonmagnetic coil form supported in spaced relation to said base, a plurality of toroidally wound coils positioned coaxially in closely spaced relation along said coil form, thin nonmagnetic, dielectric spacers substantially filling the spaces between adjacent ones of said coils, and a capacitor connected to each of said coils to form a tuned circuit at a predetermined frequency, said coils being spaced sufficiently close together so that stray capacitances between the coils are sufficient to couple the tuned circuits.
Claim 3
Dependent Claim
32 words
The filter assembly of claim 1 which includes support arms extending from said base and engaging the ends of said coil form to hold the same in spaced relation to said base.
Claim 4
Dependent Claim
23 words
The filter assembly of claim 1 in which the capacitors are disc-type capacitors arranged in rows on opposite sides of said coil form.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-29 | 1975-05-31 | 1975-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-29 | 1979-05-31 | 1979-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-29 | 1983-05-31 | 1983-11-30 | $7700.00 | Window Closed / Lapsed |