US5361737A
Expired / Lapsed
US
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Radio frequency coaxial cavity resonator as an ignition source and associated method
Assignee: West Virginia University
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Filing: 1993-12-09
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Granted: 1994-11-08
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Expires: 2013-12-09
Abstract
Abstract An apparatus for providing an ignition source for internal combustion engines comprises a radio frequency oscillator, an amplifier and a coaxial cavity resonator. The coaxial cavity resonator is adaptable for communication with a combustion chamber of the internal combustion engine. An associated method is also provided.
Inventors
- 👤 James E. Smith
- 👤 Robert M. Craven
- 👤 Kurt L. VanVoorhies
- 👤 Thomas J. Bonazza
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:24
CPC Classifications
F; F02; F02P; F02P9/00; F02P9/002; F02P9/007; F02P23/00; F02P23/04; F02P23/045
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
109 words
An apparatus for providing an ignition source for internal combustion engines, said apparatus comprising: radio frequency oscillator means for providing radio frequency power from the electrical power source of said internal combustion engine; amplifier means operably coupled with said radio frequency means for amplifying said radio frequency power; coaxial cavity resonator means having an output end portion terminating in a discharge electrode, said resonator means being operably coupled with said amplifier means for generating an RF corona discharge which ionizes a surrounding gaseous medium to create a plasma at said discharge electrode; and said resonator means being adaptable for communication with a combustion chamber of said internal combustion engine.
Claim 2
Independent Claim
109 words
An apparatus for providing an ignition source for internal combustion engines, said apparatus comprising: radio frequency oscillator means for providing radio frequency power from the electrical power source of said internal combustion engine; amplifier means operably coupled with said radio frequency means for amplifying said radio frequency power; coaxial cavity resonator means having an output end portion terminating in a discharge electrode, said resonator means being operably coupled with said amplifier means for generating an RF corona discharge which ionizes a surrounding gaseous medium to create a plasma at said discharge electrode; and said resonator means being adaptable for communication with a combustion chamber of said internal combustion engine.
Claim 3
Dependent Claim
18 words
The apparatus of claim 1, wherein said radio frequency oscillator means operates from a conventional automobile 12-volt supply.
Claim 4
Dependent Claim
23 words
The apparatus of claim 1, wherein said radio frequency oscillator means is capable of generating oscillations between about 400 MHz and 4 GHz.
Claim 5
Dependent Claim
21 words
The apparatus of claim 1, wherein said radio frequency oscillation means and said amplifier means together form a single class-C amplifier.
Claim 6
Dependent Claim
23 words
The apparatus of claim 4, wherein said resonator means is operably coupled with said class-C amplifier to operate as a tuning element therefor.
Claim 7
Dependent Claim
17 words
The apparatus of claim 1, wherein said resonator means is adapted to generate plasma which is non-propelled.
Claim 8
Dependent Claim
29 words
The apparatus of claim 1, wherein said radio frequency oscillation means produces power at a particular wavelength, and said resonator means having an electrical length one-quarter of said wavelength.
Claim 9
Dependent Claim
22 words
The apparatus of claim 1, wherein a separate coaxial cavity resonator is coupled with each combustion chamber of each internal combustion engine.
Claim 10
Dependent Claim
53 words
The apparatus of claim 1, wherein said internal combustion engine includes a piston disposed within said combustion chamber, said apparatus further including: frequency timing means for timing the generation of the plasma with respect to a position of said piston by sensing change in frequency in said combustion chamber and coaxial resonator means.
Claim 11
Dependent Claim
97 words
The apparatus of claim 1, said resonator means including: a center conductor presenting an input end and an output end, said conductor generally lying along one axis; a cavity housing having a generally cylindrical tubular shape presenting an input end and an output end, said cavity housing generally surrounding said center conductor and lying along the same axis as said center conductor; and each of the input ends being electrically shorted together and said output ends being electrically open relative to each other such that the output ends of said center conductor and cavity housing essentially align.
Claim 12
Dependent Claim
14 words
The apparatus of claim 10, wherein said center conductor output end has capacitive characteristics.
Claim 13
Dependent Claim
40 words
The apparatus of claim 10, wherein a dielectric material consists of one selected from the group consisting of the list of materials on page 8 is placed between said center conductor and cavity housing within said input and output ends.
Claim 14
Dependent Claim
27 words
The apparatus of claim 10, wherein said center conductor and cavity housing are composed of one selected from the group consisting of copper, aluminum, iron and steel.
Claim 15
Dependent Claim
44 words
The apparatus of claim 10, further including: structure defining a passageway through said center conductor wherein said passageway generally lies along the same axis as said center conductor, thereby allowing a fuel mixture to be exited at the output end of said center conductor.
Claim 16
Dependent Claim
31 words
The apparatus of claim 14, further including an electrode coupled with the output end of said center conductor, said electrode have structure defining at least one opening communicating with said passageway.
Claim 17
Dependent Claim
19 words
The apparatus of claim 10, further including: plasma modulation means for modulating a plasma generated by said resonator means.
Claim 18
Dependent Claim
42 words
The apparatus of claim 16, wherein said plasma modulation means includes electrical insulating means for insulating said housing from said internal combustion engine and modulation means coupled with said housing for causing said resonator means to act as a lumped conductive element.
Claim 19
Dependent Claim
32 words
The apparatus of claim 16, wherein said plasma modulation means includes DC isolation means for isolating said center conductor from said housing and modulation means coupled with said housing and center conductor.
Claim 20
Dependent Claim
45 words
The apparatus of claim 16, wherein said plasma modulation means includes a conductive layer surrounding at least a portion of said center conductor, said conductive layer having a capacitive relationship with said center conductor and modulation means coupled with said conductive layer and said housing.
Claim 21
Dependent Claim
44 words
The apparatus of claim 16, wherein said plasma modulation means includes a conductive annual ring coupled with said housing, said annular ring being electrically insulated from said housing and modulation means coupled with said output end of said center conductor and said annular ring.
Claim 22
Dependent Claim
18 words
The apparatus of claim 1, wherein said internal combustion engine burns an air-to-fuel ratio of greater than 19:1.
Claim 23
Dependent Claim
21 words
The apparatus of claim 1, wherein said internal combustion engine emits fewer pollutants relative to conventional spark plug internal combustion engines.
Claim 24
Independent Claim
139 words
An apparatus for providing an RF corona discharge which ionizes a surrounding gaseous medium to create a plasma, said apparatus comprising: an internal combustion engine, wherein said engine includes at least one combustion chamber, said combustion chamber presenting structure defining a receptacle for an ignition source; coaxial cavity resonator means including an output end portion terminating in a discharge electrode, said resonator means being operably coupled with said receptacle for providing an RF corona discharge which ionizes a surrounding gaseous medium to create a plasma ignition source at said discharge electrode; and a radio frequency power source means operably coupled with said coaxial cavity resonator means for providing radio frequency power to resonate through said coaxial cavity resonator means to produce an RF corona discharge which ionizes a surrounding gaseous medium to create a plasma at said discharge electrode.
Claim 25
Independent Claim
139 words
An apparatus for providing an RF corona discharge which ionizes a surrounding gaseous medium to create a plasma, said apparatus comprising: an internal combustion engine, wherein said engine includes at least one combustion chamber, said combustion chamber presenting structure defining a receptacle for an ignition source; coaxial cavity resonator means including an output end portion terminating in a discharge electrode, said resonator means being operably coupled with said receptacle for providing an RF corona discharge which ionizes a surrounding gaseous medium to create a plasma ignition source at said discharge electrode; and a radio frequency power source means operably coupled with said coaxial cavity resonator means for providing radio frequency power to resonate through said coaxial cavity resonator means to produce an RF corona discharge which ionizes a surrounding gaseous medium to create a plasma at said discharge electrode.
Claim 26
Dependent Claim
19 words
The apparatus of claim 23, wherein said radio frequency power source means operates from a conventional automobile 12-volt supply.
Claim 27
Dependent Claim
16 words
The apparatus of claim 23, wherein said radio frequency power source is a single class-C amplifier.
Claim 28
Dependent Claim
23 words
The apparatus of claim 25, wherein said resonator means is operably coupled with said class-C amplifier to operate as a tuning element therefor.
Claim 29
Dependent Claim
30 words
The apparatus of claim 23, wherein said radio frequency power source produces power at a particular wavelength, and said resonator means having an electrical length of one-quarter of said wavelength.
Claim 30
Dependent Claim
97 words
The apparatus of claim 23, said resonator means including: a center conductor presenting an input end and an output end, said conductor generally lying along one axis; an cavity housing having a generally cylindrical tubular shape presenting an input end and an output end, said cavity housing generally surrounding said center conductor and lying along the same axis as said center conductor; and each of the input ends being electrically shorted together and said output ends being electrically open relative to each other such that the output ends of said center conductor and cavity housing essentially align.
Claim 31
Dependent Claim
44 words
The apparatus of claim 28, further including: structure defining a passageway through said center conductor wherein said passageway generally lies along the same axis as said center conductor, thereby allowing a fuel mixture to be exited at the output end of said center conductor.
Claim 32
Dependent Claim
31 words
The apparatus of claim 29, further including an electrode coupled with the output end of said center conductor, said electrode have structure defining at least one opening communicating with said passageway.
Claim 33
Dependent Claim
19 words
The apparatus of claim 28, further including: plasma modulation means for modulating a plasma generated by said resonator means.
Claim 34
Dependent Claim
42 words
The apparatus of claim 31, wherein said plasma modulation means includes electrical insulating means for insulating said housing from said internal combustion engine and modulation means coupled with said housing for causing said resonator means to act as a lumped conductive element.
Claim 35
Dependent Claim
32 words
The apparatus of claim 31, wherein said plasma modulation means includes DC isolation means for isolating said center conductor from said housing and modulation means coupled with said housing and center conductor.
Claim 36
Dependent Claim
45 words
The apparatus of claim 31, wherein said plasma modulation means includes a conductive layer surrounding at least a portion of said center conductor, said conductive layer having a capacitive relationship with said center conductor and modulation means coupled with said conductive layer and said housing.
Claim 37
Dependent Claim
44 words
The apparatus of claim 31, wherein said plasma modulation means includes a conductive annual ring coupled with said housing, said annular ring being electrically insulated from said housing and modulation means coupled with said output end of said center conductor and said annular ring.
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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) | 1997-11-07 | 1998-05-09 | 1998-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-11-07 | 2002-05-09 | 2002-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-11-07 | 2006-05-09 | 2006-11-08 | $7700.00 | Window Closed / Lapsed |