Patent US3842374A successfully refreshed from Google Patents.
US3842374A
Expired / Lapsed
US
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Feedthrough filter with non-linear resistive dielectric
Assignee: Allen Bradley Co LLC
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Filing: 1973-03-09
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Granted: 1974-10-15
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Expires: 1993-03-09
Abstract
Abstract Feedthrough filters for bypassing high frequency interference signals away from a conductor carrying low frequency or direct current energy are shown. These filters employ a metal oxide type of varistor material as a dielectric between capacitor electrodes with a high dielectric constant Epsilon , and the non-linearity of current flow through the varistor material with respect to applied voltage varies by such an exponential factor that the filter functions in usual manner as a high frequency bypass for low energy interference, but as an ohmic current bypass for high energy interference regardless of frequency.
Inventors
- 👤 H Schlicke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:31
CPC Classifications
H; H01; H01P; H01P1/00; H01P1/16; H03; H03H; H03H1/00; H03H1/0007; H04; H04B; H04B1/00; H04B1/06; H04B1/10; H04B1/1018
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
83 words
In a filter the combination comprising: a feedthrough lead; a dielectric encircling said lead having a first portion comprised of a titanate and a second portion comprised of a metal oxide varistor material with a high dielectric constant; an electrode on one face of each of the dielectric portions in electrical connection with said feedthrough lead; and a second electrode on an opposite face of each of said dielectric portions adapted for connection to a conductor in shunt relation to the feedthrough lead.
Claim 2
Dependent Claim
83 words
In a filter the combination comprising: a feedthrough lead; a dielectric encircling said lead having a first portion comprised of a titanate and a second portion comprised of a metal oxide varistor material with a high dielectric constant; an electrode on one face of each of the dielectric portions in electrical connection with said feedthrough lead; and a second electrode on an opposite face of each of said dielectric portions adapted for connection to a conductor in shunt relation to the feedthrough lead.
Claim 3
Dependent Claim
108 words
In a feedthrough filter the combination comprising: a hollow metallic housing open at opposite ends; a feedthrough lead extending through the housing; a tubular dielectric surrounding the lead and disposed within said housing; a first electrode on the inside of the dielectric in electrical contact with said lead; a second electrode on the outside of said dielectric in electrical contact with said housing; a body of varistor material enclosing each end of said housing, bridging the space between said lead and the opening wall of said housing; and a pair of electrodes on each varistor body, one electrode connected with said lead and the other with said housing.
Claim 4
Dependent Claim
108 words
In a feedthrough filter the combination comprising: a hollow metallic housing open at opposite ends; a feedthrough lead extending through the housing; a tubular dielectric surrounding the lead and disposed within said housing; a first electrode on the inside of the dielectric in electrical contact with said lead; a second electrode on the outside of said dielectric in electrical contact with said housing; a body of varistor material enclosing each end of said housing, bridging the space between said lead and the opening wall of said housing; and a pair of electrodes on each varistor body, one electrode connected with said lead and the other with said housing.
Claim 5
Dependent Claim
17 words
A filter as in claim 2 wherein the bodies of varistor material are coated with a glaze.
Claim 6
Dependent Claim
117 words
In a filter for shunting very high frequency energy in the mega-hertz range from a conducting lead to a shielding enclosure, or the like, the combination with such lead of: terminal means for attachment to a shielding enclosure; a dielectric having a high dielectric constant electrically interposed between said conducting lead and said terminal means to present a capacitive shunting path between said lead and said terminal means; a high dielectric constant varistor material adjacent said dielectric in electrical parallel relationship thereto to establish an ohmic path between said lead and said terminal means; and electrodes in electrical contact with said dielectric and said varistor material for establishing said paths through said dielectric and said varistor material.
Claim 7
Dependent Claim
117 words
In a filter for shunting very high frequency energy in the mega-hertz range from a conducting lead to a shielding enclosure, or the like, the combination with such lead of: terminal means for attachment to a shielding enclosure; a dielectric having a high dielectric constant electrically interposed between said conducting lead and said terminal means to present a capacitive shunting path between said lead and said terminal means; a high dielectric constant varistor material adjacent said dielectric in electrical parallel relationship thereto to establish an ohmic path between said lead and said terminal means; and electrodes in electrical contact with said dielectric and said varistor material for establishing said paths through said dielectric and said varistor material.
Claim 8
Dependent Claim
41 words
A filter as in claim 4, in which the varistor material has a current conduction characteristic of I KV in which the value of the exponent alpha is ten or more, and has a dielectric constant of one thousand or more.
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) | 1977-10-14 | 1978-04-15 | 1978-10-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-14 | 1982-04-15 | 1982-10-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-14 | 1986-04-15 | 1986-10-15 | $7700.00 | Window Closed / Lapsed |