US4078534A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Anti-interference device for internal combustion engines
Assignee: Individual
•
Filing: 1976-05-21
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Granted: 1978-03-14
•
Expires: 1996-05-21
Abstract
Abstract The protection against interference emitted by automobile internal combustion engines or other vehicles is provided by an element for a spark plug or for a distributor, comprising a shield 3, a resistor 4 increasing with the frequency to be filtered and a capacitor 5, selected in such a manner that the RC product is higher than the time constant corresponding to the cut-off frequency. Good reduction of interference is obtained between 10 and 1000 MHz.
Inventors
- 👤 Ferdy P. Mayer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 00:28
CPC Classifications
H; H01; H01T; H01T13/00; H01T13/02; H01T13/04; H01T13/05
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
109 words
A reinforced filter for a spark plug and high voltage distribution system for an internal combustion engine ignition cable, employing a series resistor having a resistance R and a shunt capacitor having a capacitance C connected to ground, wherein the filter terminates the high voltage cable and serves as a connecting end element in the high voltage distribution system, the resistance R and the capacitance C form a quadrupole and are selected in such a manner that the RC product becomes higher than the time constant corresponding to the desired cut-off frequency, the resistor is designed in such a manner as not to exhibit a disadvanteous interference shunt capacitance.
Claim 2
Dependent Claim
109 words
A reinforced filter for a spark plug and high voltage distribution system for an internal combustion engine ignition cable, employing a series resistor having a resistance R and a shunt capacitor having a capacitance C connected to ground, wherein the filter terminates the high voltage cable and serves as a connecting end element in the high voltage distribution system, the resistance R and the capacitance C form a quadrupole and are selected in such a manner that the RC product becomes higher than the time constant corresponding to the desired cut-off frequency, the resistor is designed in such a manner as not to exhibit a disadvanteous interference shunt capacitance.
Claim 3
Dependent Claim
26 words
A filter according to claim 1, wherein the resistor is of the localized type induced by magnetic coupling by one or more structures surrounding the conductor.
Claim 4
Dependent Claim
24 words
A filter according to claim 2, wherein the resistor is constituted by one or more rings manufactured from a magnetic high frequency lossey product.
Claim 5
Dependent Claim
16 words
A filter according to claim 3, wherein the magnetic high frequency lossey product is a ferrite.
Claim 6
Dependent Claim
18 words
A filter according to claim 3, wherein the magnetic high frequency lossey product is a mixture containing ferrite.
Claim 7
Dependent Claim
15 words
A filter according to claim 1, wherein the shunt capacitor is of the localized type.
Claim 8
Dependent Claim
15 words
A filter according to claim 1, wherein the series resistor is of the distributed type.
Claim 9
Dependent Claim
18 words
A filter according to claim 7, wherein the resistor is constituted by a portion of the ignition cable.
Claim 10
Dependent Claim
16 words
A filter according to claim 7, wherein the shunt capacitor is distributed along the distributed resistor.
Claim 11
Dependent Claim
16 words
A filter according to claim 1, wherein the ground electrode of the shunt capacitor is resistant.
Claim 12
Dependent Claim
35 words
A filter according to claim 7, wherein the ground electrode of the shunt capacitor is constituted by a layer surrounding at least partially the resistor distributed over at least a portion of its connection length.
Claim 13
Dependent Claim
17 words
A filter according to claim 1, wherein the resistor comprises a localized portion and a distributed portion.
Claim 14
Dependent Claim
17 words
A filter according to claim 12, wherein the capacitor comprises a localized portion and a distributed portion.
Claim 15
Dependent Claim
19 words
A filter according to claim 1, wherein the resistor has a resistance increasing with frequency ω to be filtered.
Claim 16
Dependent Claim
27 words
A filter according to claim 1, wherein the capacitor utilizes as a hot electrode the normal structure of the plug and its connection with the ignition cable.
Claim 17
Dependent Claim
28 words
A filter according to claim 1, wherein the capacitor utilizes as a hot electrode the normal structure of the distributor terminal and a portion of the ignition cable.
References Cited (Backward Citations)
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US2790053A
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US2896120A
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US3191133A
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US3178661A
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US3191132A
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US3309633A
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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) | 1981-03-13 | 1981-09-12 | 1982-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-13 | 1985-09-12 | 1986-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-13 | 1989-09-12 | 1990-03-14 | $7700.00 | Window Closed / Lapsed |