US5838216A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Common-mode EMI filter
Assignee: Sundstrand Corp
•
Filing: 1996-09-06
•
Granted: 1998-11-17
•
Expires: 2016-09-06
Abstract
Abstract The present invention is an improved filter assembly for providing at least common-mode filtering. A filter assembly in accordance with the present invention includes a plurality of spaced apart electrical conductors (102) for carrying at least common-mode electrical current; a housing (104) electrically isolated from the plurality of electrical conductors and containing a portion of a length of the plurality of electrical conductors, the housing having an interior cavity (104) defined by a wall (112) having at least a partially electrically conductive section (114), the wall extending outward from two longitudinally spaced apart locations on the plurality of electrical conductors and between the plurality of electrical conductors at a position spaced from the plurality of electrical conductors to form the cavity; at least one inductive element (108) in a closed lower reluctance loop extending around the plurality of electrical conductors and electrically isolated therefrom and the electrically conductive portion of the wall to provide an inductance common to the plurality of electrical conductors; and at least one capacitive element (110), each capacitive element having an electrical contact with the electrically conductive portion of the wall and the plurality of electrical conductors to provide capacitance between the plurality of electrical conductors and the electrically conductive portion of the wall.
Inventors
- 👤 Curtis B. White
- 👤 W. Kyle Anderson
- 👤 Frank W. Allen, III
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 20:25
CPC Classifications
H; H01; H01G; H01G4/00; H01G4/35
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
208 words
A filter assembly for providing at least common-mode filtering comprising: a plurality of spaced apart electrical conductors for carrying at least common-mode electrical current; a housing electrically isolated from the plurality of electrical conductors and containing a length of the plurality of electrical conductors, the housing having an interior cavity defined by a wall having at least a partially electrically conductive section, the wall extending outward from two longitudinally spaced apart locations of the length of the plurality of electrical conductors and between the plurality of electrical conductors at a position spaced from the plurality of electrical conductors to form the cavity; at least one inductive element formed into a closed loop of low reluctance extending around the plurality of electrical conductors and electrically isolated therefrom and the electrically conductive section of the wall to provide an inductance common to the plurality of electrical conductors; and at least one capacitive element providing common mode filtering of the common mode electrical current flowing in the plurality of spaced apart electrical conductors each capacitive element having an electrical contact with the electrically conductive section of the wall and the plurality of electrical conductors to provide capacitance between the plurality of electrical conductors and the electrically conductive section of the wall.
Claim 2
Dependent Claim
208 words
A filter assembly for providing at least common-mode filtering comprising: a plurality of spaced apart electrical conductors for carrying at least common-mode electrical current; a housing electrically isolated from the plurality of electrical conductors and containing a length of the plurality of electrical conductors, the housing having an interior cavity defined by a wall having at least a partially electrically conductive section, the wall extending outward from two longitudinally spaced apart locations of the length of the plurality of electrical conductors and between the plurality of electrical conductors at a position spaced from the plurality of electrical conductors to form the cavity; at least one inductive element formed into a closed loop of low reluctance extending around the plurality of electrical conductors and electrically isolated therefrom and the electrically conductive section of the wall to provide an inductance common to the plurality of electrical conductors; and at least one capacitive element providing common mode filtering of the common mode electrical current flowing in the plurality of spaced apart electrical conductors each capacitive element having an electrical contact with the electrically conductive section of the wall and the plurality of electrical conductors to provide capacitance between the plurality of electrical conductors and the electrically conductive section of the wall.
Claim 3
Dependent Claim
74 words
A filter assembly in accordance with claim 1 wherein: each capacitive element comprises a stack of spaced apart conductive layers having a number of apertures equal in number at least to a number of the plurality of electrical conductors which extend through the layers, respectively receive a different one of the plurality of electrical conductors and which each respectively form an electrical contact with a different one of the plurality of the electrical conductors.
Claim 4
Dependent Claim
124 words
A filter assembly in accordance with claim 2 wherein: the plurality of conductive layers further comprise a plurality of first conductive layers which are spaced apart and electrically insulated from each other and are in electrical contact with only one of the plurality of electrical conductors, a plurality of second conductive layers which are spaced apart and electrically insulated from each other and electrically insulated from the first conductive layers and are in electrical contact with only another one of the plurality of electrical conductors, and a plurality of third conductive layers which are spaced apart and electrically insulated from each other and electrically insulated from the first and second conductive layers and in electrical contact with the electrically conductive section of the wall.
Claim 5
Dependent Claim
32 words
A filter assembly in accordance with claim 3 wherein: pairs of the first and second conductive layers are disposed in a common plane in the stack and electrically insulated from each other.
Claim 6
Dependent Claim
30 words
A filter assembly in accordance with claim 4 wherein: the at least one inductive element is a ferromagnetic toroid; and the at least one capacitive element is a ceramic capacitor.
Claim 7
Dependent Claim
30 words
A filter assembly in accordance with claim 3 wherein: the at least one inductive element is a ferromagnetic toroid; and the at least one capacitive element is a ceramic capacitor.
Claim 8
Dependent Claim
33 words
A filter assembly in accordance with claim 3 wherein: the stack of conductive layers alternate in electrical connection with the conductive section of the wall and one of the plurality of electrical conductors.
Claim 9
Dependent Claim
30 words
A filter assembly in accordance with claim 7 wherein: the at least one inductive element is a ferromagnetic toroid; and the at least one capacitive element is a ceramic capacitor.
Claim 10
Dependent Claim
75 words
A filter assembly in accordance with claim 3 wherein: the first and second conductive layers each have the plurality of apertures for receiving the plurality of electrical conductors with each of the apertures of each of the first or second plurality of conductive layers being in electrical contact with a different one of the plurality of electrical conductors with each of the first and second conductive layers being in a different plane in the stack.
Claim 11
Dependent Claim
30 words
A filter assembly in accordance with claim 9 wherein: the at least one inductive element is a ferromagnetic toroid; and the at least one capacitive element is a ceramic capacitor.
Claim 12
Dependent Claim
33 words
A filter assembly in accordance with claim 2 wherein: the stack of conductive layers alternate in electrical connection with the conductive section of the wall and one of the plurality of electrical conductors.
Claim 13
Dependent Claim
30 words
A filter assembly in accordance with claim 11 wherein: the at least one inductive element is a ferromagnetic toroid; and the at least one capacitive element is a ceramic capacitor.
Claim 14
Dependent Claim
30 words
A filter assembly in accordance with claim 2 wherein: the at least one inductive element is a ferromagnetic toroid; and the at least one capacitive element is a ceramic capacitor.
Claim 15
Dependent Claim
79 words
A filter assembly in accordance with claim 2 further comprising: at least one outer electrically conductive sleeve, each outer electrically conductive sleeve being in electrical contact with an inner surface of the conductive section of the wall and an outer periphery of at least one capacitive element; and at least one inner electrically conductive sleeve, each inner electrically conductive sleeve being in electrical contact with only one of the apertures and only one of the plurality of electrical conductors.
Claim 16
Dependent Claim
30 words
A filter assembly in accordance with claim 14 wherein: the at least one inductive element is a ferromagnetic toroid; and the at least one capacitive element is a ceramic capacitor.
Claim 17
Dependent Claim
30 words
A filter assembly in accordance with claim 1 wherein: the at least one inductive element is a ferromagnetic toroid; and the at least one capacitive element is a ceramic capacitor.
Claim 18
Dependent Claim
74 words
A filter assembly in accordance with claim 1 further comprising: at least one additional inductive element, each additional inductive element being formed into a low reluctance closed loop extending around less than all of the plurality of electrical conductors and electrically isolated therefrom and the electrically conductive section of the wall to provide differential-mode filtering of electrical current flowing in the less than all the plurality of electrical conductors contained in the closed loop.
Claim 19
Dependent Claim
58 words
A filter assembly in accordance with claim 1 further comprising: at least one additional capacitive element, each additional capacitive element being electrically isolated from the electrically conductive section of the wall and electrically connected to less than the plurality of electrical conductors to provide differential-mode filtering of electrical current flowing in less than the plurality of electrical conductors.
Claim 20
Dependent Claim
84 words
A filter assembly in accordance with claim 18 wherein: each additional capacitive element comprises an additional stack of spaced apart conductive layers having at least one aperture which extends through the additional stack and which forms an electrical contact with at least one of the plurality of electrical conductors with a different aperture contacting a different one of the at least one electrical conductor and being electrically isolated from the conductive section of the housing which extends between the two longitudinally spaced apart locations.
Claim 21
Dependent Claim
117 words
A filter assembly in accordance with claim 19 wherein the at least one additional capacitive element comprises: at least one first electrically conductive layer and at least one second electrically conductive layer, each of the first and second electrically conductive layers being spaced apart and electrically insulated from each other, the at least one first electrically conductive layer being in electrical contact with the at least one of the plurality of electrical conductors through electrical contact with one aperture and not in electrical contact with the conductive section of the wall and the at least one second electrically conductive layer being electrically insulated from the at least one electrical conductor and the conductive section of the wall.
Claim 22
Dependent Claim
101 words
A filter assembly in accordance with claim 1 further comprising: at least one insulating adhesive layer, each insulating adhesive layer connecting a face of one of the at least one inductive element to a face of one of the at least one capacitive element; and at least one force applying element, each force applying element applying a force axially to at least one inductive and at least one capacitive element connected with the insulating adhesive layer and further providing for compensation for variation in a dimension of the at least one inductive and capacitive element parallel to the plurality of conductors.
Claim 23
Dependent Claim
17 words
A filter assembly in accordance with claim 21 wherein: each force applying element is a compressed O-ring.
Claim 24
Dependent Claim
41 words
A filter assembly in accordance with claim 22 wherein: each O-ring contacts a face of one of the at least one inductive element or a face one of the at least one capacitive element extending from the plurality of electrical conductors.
Claim 25
Dependent Claim
55 words
A filter assembly in accordance with claim 1 wherein: the wall of the housing comprises two conductive parts which are connected together by an insulative adhesive and a conductive element which is disposed inside of the housing which electrically connects the two conductive parts to provide an electrical current flow path around the insulative adhesive.
Claim 26
Dependent Claim
14 words
A filter assembly in accordance with claim 24 wherein: the adhesive is thermally actuated.
Claim 27
Dependent Claim
166 words
A filter assembly for providing at least common-mode filtering comprising: a plurality of spaced apart electrical conductors for carrying at least common-mode electrical current; a housing electrically isolated from the a plurality of electrical conductors and containing a length of the plurality of electrical conductors, the housing having an interior cavity defined by a wall having at least a partially electrically conductive section, the wall extending outward from two longitudinally spaced apart locations on the length of the plurality of electrical conductors and between the plurality of electrical conductors at a position spaced from the a plurality of electrical conductors to form the cavity; and at least one capacitive element providing common filtering of the common mode electrical current flowing in the plurality of spaced apart electrical conductors, each capacitive element having an electrical contact with the electrically conductive section of the wall and the plurality of electrical conductors to provide capacitance between the plurality of electrical conductors and the electrically conductive section of the wall.
Claim 28
Dependent Claim
166 words
A filter assembly for providing at least common-mode filtering comprising: a plurality of spaced apart electrical conductors for carrying at least common-mode electrical current; a housing electrically isolated from the a plurality of electrical conductors and containing a length of the plurality of electrical conductors, the housing having an interior cavity defined by a wall having at least a partially electrically conductive section, the wall extending outward from two longitudinally spaced apart locations on the length of the plurality of electrical conductors and between the plurality of electrical conductors at a position spaced from the a plurality of electrical conductors to form the cavity; and at least one capacitive element providing common filtering of the common mode electrical current flowing in the plurality of spaced apart electrical conductors, each capacitive element having an electrical contact with the electrically conductive section of the wall and the plurality of electrical conductors to provide capacitance between the plurality of electrical conductors and the electrically conductive section of the wall.
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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) | 2001-11-16 | 2002-05-18 | 2002-11-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-11-16 | 2006-05-18 | 2006-11-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-11-16 | 2010-05-18 | 2010-11-17 | $7700.00 | Window Closed / Lapsed |