Combustion initiation device and method for tuning a combustion initiation device

Information

  • Patent Grant
  • 6559376
  • Patent Number
    6,559,376
  • Date Filed
    Tuesday, March 28, 2000
    25 years ago
  • Date Issued
    Tuesday, May 6, 2003
    22 years ago
Abstract
An ignition cable constructed according to a method for optimizing an ignition cable, the cable including at least a capacitor, where the ignition cable carries current from a power source to a spark plug located in a combustion chamber. The ignition cable includes a center element structured to communication electric current from the power source to the sparkplug and an insulator surrounding the center element. The conductor is removably coupled to a ground, and surrounds at least a portion of the insulator. The center element, insulator and conductor form a capacitor having an optimal capacitance value that is determined by finding a maximum capacitance value and subtracting a safety margin.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention generally relates to initiating combustion of fuel-air mixtures. More particularly, the invention concerns a spark plug cable and a method for tuning a spark plug cable system to maximize combustion of fuel-air mixtures in internal combustion engines.




2. Discussion of the Related Art




The purpose of an ignition system is to initiate combustion of a flammable fuel-air mixture by igniting it at precisely the right moment. In spark-ignition engines, this is achieved with an electrical spark, that is, by an ark discharged between two, or more electrodes of a spark plug. An electrical potential difference, or voltage builds between the spark plug electrodes until a spark arks from one electrode to the other(s). The voltage is created by the delivery of current to the center electrode of the spark plug. A spark plug cable, or ignition wire delivers the current from a current generating device, such as a coil to the spark plug.




Combustion initiation in modern-day spark ignition engines is becoming increasingly difficult. This is because engine designs that increase fuel economy and reduce harmful environmental emissions have created unfavorable conditions for fuel-air ignition. Modern-day engines employ lean fuel-air mixtures that are difficult to ignite. Turbochargers and superchargers are also employed to increase engine efficiency. However, the increased engine combustion chamber pressures gene turbochargers and superchargers also hinder combustion. In addition, the spacing, or gap between the spark plug's electrodes has increased, thereby increasing the amount of voltage necessary to create an ark.




SUMMARY OF THE INVENTION




The present invention solves the problem of igniting fuel-air mixtures in the difficult conditions found in modern-day engines. Broadly, the present invention provides for complete fuel-air combustion, thereby increasing engine power and decreasing harmful environmental emissions.




One embodiment of a spark plug cable constructed according to the present invention comprises a core wire extending between two ends, with one end coupled to a spark plug connector and the other end coupled to a power source. An insulator encases the core wire and a metallic sleeve encases at least a portion of the insulator. The metallic sleeve is also removeably coupled to an electrical ground. The metallic sleeve, insulator and core wire form a capacitor. An optimal capacitance value is determined by finding a maximum capacitance value and subtracting a safety margin.




Another method of the invention optimizes spark duration by coupling a resistor and a capacitor to the spark plug cable, determining an available charge from the capacitor, and selecting an ideal resistance value based on the available charge, wherein the ideal resistance value will enable the generation of a very powerful spark, thereby maximizing combustion of the fuel-air mixture.




However, the claims alone—not the preceding summary—define the invention.











BRIEF DESCRIPTION OF THE DRAWING




The nature, goals, and advantages of the invention will become more apparent to those skilled in the art after considering the following detailed description when read in connection with the accompanying drawing—illustrating by way of examples the principles of the invention—in which like reference numerals identify like elements throughout wherein:





FIG. 1

is an elevation view of one embodiment of the present invention in the form of a spark plug cable;





FIG. 2

is a cut-away elevation view of a spark plug cable constructed according to the method of the present invention;





FIG. 3

is an elevation view of a section of the embodiment of

FIG. 2

, showing specific elements of the spark plug cable;





FIG. 4

is a schematic circuit diagram depicting ignition system components and a spark plug cable constructed according to a method of the present invention;





FIG. 5

is a flow chart depicting a method for optimizing a spark plug cable according to the present invention; and





FIG. 6

is an elevation view showing the direction of a current and magnetic field generated by a component of the spark plug cable according to the present invention.




It will be recognized that some or all of the Figures are schematic representations for purposes of illustration and do not necessarily depict the actual relative sizes or locations of the elements shown.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS




In the following paragraphs, the present invention will be described in detail by way of example with reference to the attached drawings.




General




Throughout this description, the preferred embodiment and examples shown should be considered as exemplars, rather than as limitations on the present invention.




The purpose of an ignition system is to produce a powerful enough spark to initiate combustion of a fuel-air mixture. As shown in

FIG. 1

, an automotive ignition system comprises, in part, a spark plug


12


mounted in a cylinder head


9


, a spark plug cable or ignition wire


10


and a current or power source


11


such as a coil. The spark plug cable is coupled to the spark plug by a spark plug boot


5


and to the power source by a power source boot


7


. An ideal ignition system will ignite all of the fuel-air mixture and will ignite the fuel-air mixture at the precise moment to create maximum power. Therefore, the ignition system must be consistent and precise. An optimized ignition system will produce more power and less harmful environmental pollutants.




As shown in the drawings for purposes of illustration, an ignition wire, or spark plug cable constructed and optimized according to the method of the present invention provides a way to improve fuel-air combustion. The spark plug cable is tuned to provide current to the spark plug in a manner that creates an increased spark intensity, or power compared to conventional spark plug cables. In addition, the present invention provides a method for optimizing spark duration, that is, the amount of time the spark lasts, by adjusting, or tuning the spark plug cable components relative to each other.




Structure




As shown in

FIGS. 1 and 2

, a spark plug cable, or ignition wire constructed in accordance with one method of the present invention is illustrated and designated generally by the numeral


10


. The spark plug cable is configured to carry current from a current or power source


11


to a spark plug


12


. The power source is usually an ignition coil, however a magneto or other suitable device can also be used. Center element or core strand


13


carries the current from the power source


11


to the spark plug


12


. The spark plug cable also comprises an insulator or dielectric


16


surrounding the core strand and a conductor


20


that extends along a section of the spark plug cable and surrounds at least a portion of the insulator. Protective boots


8


are employed in some embodiments to cover the ends of the conductor, and to keep the conductor securely attached to the insulator. In one embodiment, the conductor has a ground strap


21


that is fixed to a ground by connector


22


. The core strand and conductor are configured to form the electrodes of a capacitor. Current sent from the power source


11


is stored in the capacitor and later delivered to the spark plug creating a powerful spark.




Referring to

FIG. 3

, one embodiment of a spark plug cable constructed according to the present invention comprises a core strand or element


13


constructed of a central fiber


14


, cover


28


and spiral-wound wire


15


. The central fiber is comprised of a super low conductive material having a resistance of 7,000 Ohm per inch. The central fiber can be comprised of one single element, or it can be comprised of a plurality of filament-like elements. When multiple filaments are employed, a cover


28


is used to bundle the filaments together. The central fiber is surrounded by an approximately 0.1 millimeter (mm) diameter helical-, or spiral-wound wire


15


having approximately 65 windings per inch. In this embodiment, the resistance of the core strand, comprised of the central fiber, cover and the spiral-wound wire, is approximately 28 Ohm per inch.




An alternative embodiment core strand is comprised of a central fiber


14


having a plurality of filament-like elements bound together by cover


28


. In this embodiment, a ferromagnetic material, in a powder-like form, is bound by the cover


28


to the filaments. Surrounding the cover is an approximately 0.15 millimeter (mm) diameter helical-, or spiral-wound wire


15


having approximately 82 windings per inch. In this embodiment, the resistance of the core strand, comprised of the central fiber, ferromagnetic powder, cover and the spiral-wound wire, is approximately 14 Ohm per inch. Other embodiment spiral-wound wires could be larger or smaller in diameter, thereby varying the overall resistance of the core strand. Another way to vary the overall resistance of the core strand is to change the number of spiral-wound wire windings per inch. Alternatively, any conductive material can be used to form the core strand, such as steel, silver, copper or other suitable materials.




Surrounding the spiral-wound strand


15


is dielectric, or insulator


16


. A preferred embodiment uses a high-purity silicone dielectric, but rubber or other suitable dielectric materials can also be employed. As shown in

FIG. 3

, one specific embodiment uses a two-layer dielectric separated by a woven fiberglass member


17


. The fiberglass member reinforces and supports the dielectric. Dielectric


16


can vary in thickness from about 2.5 mm to about 5 mm. That is, the outer diameter of the dielectric can vary from about 5 mm to about 10 mm.




As shown in

FIGS. 2 and 3

, conductor


20


surrounds the dielectric material. Any conductive material can be used to form the conductor, such as steel, silver, copper or other suitable materials. A preferred embodiment conductor is comprised of a braided copper wire having tin plating. One specific embodiment conductor uses 36-gauge copper wire woven into bundles or threads


6


to form a flexible, collapsible tube. The woven wire in this specific embodiment is comprised of 24 bundles, each bundle having 16 individual filaments. An alternative embodiment conductor can be comprised of woven flexible tubes made of 36 bundles, with each bundle having 7 individual filaments, with each filament being 30-gauge wire. Another alternative embodiment conductor can be comprised of woven flexible tubes made of 48 bundles, with each bundle having 7 individual filaments, with each filament being 32-gauge wire.




As shown in

FIG. 3

, a plurality of openings or spaces


27


can be formed between the individual bundles


6


. However, these openings can be minimized or eliminated by manipulating the flexible wire tubes. For example, a preferred embodiment conductor tube achieves approximately 95% coverage of the dielectric. However, alternative embodiment conductor tubes can cover about 75% to about 100% of the dielectric.




Referring to

FIG. 2

, the bundles


6


comprising the tube-like conductor


20


can be collapsed so that one end of the conductor


20


forms a flexible, substantially flat ground strap


21


. The ground strap is formed when the spark plug cable


10


is assembled. One opening


27


between the bundles comprising the conductor is enlarged to allow passage of the insulator


16


and core strand


13


. In one embodiment, the ground strap


21


terminates with connector


22


comprising a ring terminal, or wire terminal


42


for securely connecting by a suitable fastener to a ground, such as an engine block.




A spark plug cable constructed using a flexible conductor


20


according to the present invention can be packaged by flexing or compressing the flexible conductor into any necessary configuration. Prior art capacitive spark plug cables using rigid capacitors have limited applications because of the packaging limitation of a rigid cylindrical object.




Operation and Tuning





FIG. 4

is a schematic circuit diagram of one embodiment of a tuned, or optimized spark plug cable constructed according to the method of the present invention. The conductor


20


is positioned between the power source


11


, such as a coil, and the center electrode


23


of a spark plug


12


. Ground strap


21


connects the conductor to ground


26


preferably located on the engine. In one embodiment, core strand


13


is configured to have a resistance


25


of about 28 Ohm per inch. One theory of the operation of a spark plug cable constructed according to the present invention is that when current is sent from the power source through the core strand, the current is attracted to the ground


21


of a capacitor formed by the conductor, insulator


16


and the core strand. The core strand


13


and conductor


20


become capacitor electrodes separated by the insulator. The capacitor stores the energy sent by the coil until its capacity is reached. A final amount of energy sent by the coil passes the capacitor and generates sufficient voltage between spark plug electrodes


23


and


24


to create a spark. The capacitor then discharges, sending all of its stored energy to the spark plug in a burst, creating a powerful spark.




Prior art spark plug cables without capacitors simply delivered the coil energy to the spark plug. However, the coil cannot deliver the required energy in a short burst, but instead requires time to generate it. This creates a spark duration or time that is too long—between about two to four thousands of a second (0.002-0.004 sec). A long spark duration decreases spark power, because Power=Work/time. Therefore, by decreasing spark duration, spark power can be increased. Increased spark power improves the performance of modern-day engines that use lean fuel-air mixtures and have high combustion chamber temperatures and pressures.




Prior art devices delivered the stored capacitor energy in too short a time, creating a spark duration so short that ignition of the fuel-air mixture was erratic, or non-existent. Alternatively, the capacitance was too small, generally because the capacitor's size was limited by space constraints, and there was no improvement in ignition of the fuel-air mixture.




The capacitor mounted on the spark plug cable was often too large and the capacitor stored all of the energy sent by the coil. In this situation, no spark is generated to initiate fuel-air combustion.




A spark plug cable configured according to the method of the present invention has a spark duration in the range of 40 to 1000 nanoseconds. Therefore, spark power is significantly increased, and complete combustion, even under unfavorable conditions is assured. In addition, the spark plug cable capacitor is carefully sized, or tuned to the coil so that the capacitor is fully charged, yet sufficient energy is generated at the center electrode


23


to create a spark. Also, the resistance of the core strand


13


must be optimized so that spark duration is in the desired range to initiate combustion. A spark plug cable that performs as described above must be carefully tuned and constructed.





FIG. 5

depicts a method for tuning spark plug cable


10


having an optimal capacitance value. The method of the present intention can be used to construct a spark plug cable that can be used on any device requiring spark ignition of a flammable fuel, such as 2-stroke engines, 4-stroke engines, and other fuel burning devices.




The first step


30


is to determine the available current. This is accomplished by inspecting the power source to determine its output. A conventional power source employs an ignition coil that amplifies 12 volts (V) received from a conventional battery to approximately 20,000 V. Alternative power sources can supply 6, 24, 36 or 42 volts to the ignition coil. Moreover, voltages can range from 5,000 V to 80,000 V, or more, depending upon the coil characteristics.




The next step


31


is to select an optimal capacitance value. The capacitor must be sized so that it becomes fully charged, yet it must also allow passage of sufficient energy or current to create a spark at the spark plug. If the capacitance of the capacitor is too large, a spark will not form and combustion of the fuel-air mixture will not occur. Conversely, if the capacitance of the capacitor is too small, spark intensity will not change, and there will be no improvement to ignition of the fuel-air mixture. A capacitor having an optimal capacitance value is determined by finding a maximum capacitance value and subtracting a safety margin.




For example, different spark plug cables can be constructed to exhibit different capacitance values, such as those of Table 1, shown below.















TABLE 1









Spark Plug




Cable Length




Capacitor Length




Capacitance






Cable #




(inches)




(inches)




(pico farads)


























1




30″




0




0






2




30″




5




18






3




30″




10




33






4




30″




15




48






5




30″




20




63






6




30″




25




74






7




40″




35




95














The different spark plug cables can then be tested with coils having different output voltages. The optimal capacitance value will vary based on the size of the coil used in the ignition system. For example, in the three tests shown below, three different coils having outputs of 40,000 volts (40 kV), 60 kV and 70 kV, require three different spark plug cable capacitors.

















TEST 1














Chamber Pressure




100 psi of Nitrogen







Frequency




250 Hz







Plug Gap




0.050″







Coil Output Voltage




40 kV












Spark Plug Cable #




Spark Generation









1




Conventional spark






2




Optimal Spark






3




Intermittent sparking






4




No spark






5




No spark






6




No spark






7




No spark














TEST 2














Chamber Pressure




100 psi of Nitrogen







Frequency




250 Hz







Plug Gap




0.050″







Coil Output Voltage




60 kV












Spark Plug Cable #




Spark Generation









1




Conventional spark






2




Conventional spark






3




Conventional spark






4




Optimal Spark






5




Intermittent sparking






6




No spark






7




No spark














TEST 3














Chamber Pressure




100 psi of Nitrogen







Frequency




250 Hz







Plug Gap




0.050″







Coil Output Voltage




70 kV












Spark Plug Cable #




Spark Generation









1




Conventional spark






2




Conventional spark






3




Conventional spark






4




Conventional spark






5




Conventional spark






6




Optimal Spark






7




Intermittent sparking














As shown in the test results above, to achieve optimum spark, the capacitance value of the spark plug cable must be increased as the voltage output of the coil increases. The optimal capacitance value for each ignition system is determined by finding the maximum capacitance value and subtracting a safety margin. The maximum capacitance value is the capacitance value of the spark plug cable that causes intermittent, sporadic or no spark at the spark plug. For example, in Test 1, the maximum capacitance value is 38 pF, found in spark plug cable


3


. In Test 2, the maximum capacitance value is 63 pF, found in spark plug cable


5


. And in Test 3, the maximum capacitance value is 95 pF, found in spark plug cable


7


.




To make certain that a spark is developed at the spark plug under virtually all conditions, a small safety margin is subtracted from the maximum capacitance value to arrive at the optimal capacitance value. A capacitance decrease of about 10 to 15 pF has been found to be a sufficient safety margin. This allows for manufacturer variations, power source deterioration, transient ignition system conditions and other effects.




Once the small safety margin has been subtracted from the maximum capacitance value, the optimal capacitance value is found. In test 1, the optimal capacitance value is 18 pF, found in cable


2


. In test 2, the optimal capacitance value is 48 pF, found in cable


4


, and in test 3, the optimal capacitance value is 74 pF, found in cable


6


.




Therefore, the optimal capacitance value for a specific ignition system can be determined and a spark plug cable can be constructed accordingly. The method of constructing a spark plug cable according to the present invention allows for the optimum spark to be developed by tuning the spark plug cable to the specific ignition system requirements.




As shown in

FIG. 5

, the next step


32


in tuning the spark plug cable


10


is to adjust the capacitance of the capacitor so that it matches the optimal capacitance value. One way to adjust a capacitor's capacitance is to vary its surface area. Therefore, one tuning method is to simply adjust length


18


, shown in

FIG. 2

, of conductor


20


to reach the desired capacitance value. This length can vary from about 5 to 40 inches.




One advantage of the present invention is that because the conductor


20


is comprised of a flexible braided wire tube, the surface area of the conductor can be increased or decreased by opening or closing the plurality of spaces


27


, shown in

FIG. 3

, that exist between the braided bundles


6


. For example, a motorcycle with a high-voltage coil requiring a large capacitor will only accommodate a short spark plug cable. The conductor can be compressed so that the spaces between the wire bundles are removed, thereby increasing its surface area and capacitance of the spark plug cable.




Another way of sizing the capacitor is to increase the surface area of the spiral-wound wire


15


located about the central fiber


14


of core strand


13


. The surface area is increased by increasing the number of windings per inch. This increases the surface area of the core strand, thereby increasing the capacitance of the capacitor. However, it also increases the resistance of the core strand. This advantageous feature will be discussed in further detail below.




As shown in

FIG. 3

, another method of sizing, or tuning the capacitor is to increase the spacing


19


between the core strand


13


and the conductor


20


, as capacitance can also be adjusted by changing the distance between the capacitor electrodes. This can be accomplished by changing the thickness of dielectric


16


. A preferred embodiment dielectric has an outer diameter of about 8 millimeters, with a spacing


19


of about 4 mm. However, depending upon the capacitor requirements, a larger or smaller dielectric diameter could be employed.




As shown in

FIG. 5

, once the capacitor has been optimally sized, the next step


33


in tuning the spark plug cable


10


is to determine the ideal spark duration, or time. A long spark duration decreases spark power, because Power=Work/time. Therefore, by decreasing spark duration, spark power can be increased. Conventional ignition systems have a spark duration that is too long—between about two to four thousands of a second (0.002-0.004 sec). Prior art devices deliver the energy to create the spark in too short a time, creating a spark duration so short that ignition of the fuel-air mixture is erratic, or non-existent. Alternatively, an insufficient amount of energy is sent, resulting in no increase in spark power. A spark plug cable configured according to the method of the present invention has a spark duration in the range of 40 to 1000 nanoseconds. Therefore, spark power is significantly increased, and complete combustion, even under unfavorable conditions is assured.




Referring again to

FIG. 5

, once the correct spark duration is determined, the next step


34


in tuning the spark plug cable


10


is to select an ideal resistance. One unique aspect of the method of the present invention is to optimize, or tune the spark duration by adjusting the resistance of core strand


13


. Greater resistance increases spark duration and conversely, less resistance decreases spark duration. A preferred embodiment spark plug cable


10


will have a spark duration of about 300 nanoseconds. However, depending upon the requirements of the ignition system, spark duration may range from about 40 to about 1000 nanoseconds.




An important factor when selecting ideal resistance is the capacitor characteristics. Prior art capacitors employing a rigid barrel-type structure will quickly “dump” its stored energy, creating a spark of extremely short duration. Spark durations that are too short will not ignite the fuel-air mixture. Conversely, spark durations that are too long will not increase the power of the spark, thereby having no beneficial effect. One advantage of the present invention is that conductor


20


, comprised of a braided wire tube, can be configured to have a controlled release of its stored energy, thereby creating a spark of any specified duration. This is accomplished by using different wire braiding configurations, each having its own discharge characteristics. For example, a conductor comprised of a wire braid consisting of 24 bundles, each bundle having 16 individual filaments of 36-gauge copper wire, will have a different discharge characteristic than a conductor comprised of a wire braid consisting of 48 bundles, each bundle having 7 individual filaments of 32-gauge copper wire.




The ideal resistance is selected by examining the capacitance of the capacitor, the capacitor's discharge characteristics, and the resistance between the capacitor and the spark plug, as all of these factors affect spark duration.




Shown in

FIG. 5

, the next step


35


is to adjust the resistance of spark plug cable


10


to approximate the ideal resistance. As shown in

FIG. 2

, the resistance of consequence is the resistance generated by length


29


of core strand


13


. Length


29


is the span between spark plug


12


and the end of conductor


20


. This is the resistance the capacitor must overcome to send its stored energy to the spark plug.




One way to adjust the resistance is to increase the number of spiral-wound wires


15


per inch on core strand


13


, shown in

FIG. 3. A

preferred embodiment core wire has a resistance of approximately 28 Ohm per inch. However, this resistance value can be increased or decreased depending upon the ignition system requirements. An alternative method is to increase length


29


, thereby increasing the total resistance between the spark plug


12


and the end of conductor


20


.




An important feature of the spiral-wound wires


15


is that they minimize electromagnetic interference (EMI) generated by the electrical energy sent to the spark plug. The EMI can be in the form of unwanted high-frequency electrical signals also known as radio-frequency interference (RFI). Modern engine electronics are extremely sensitive to EMI. Some ignition systems employing high-voltage coils can produce excessive, and damaging, amounts of EMI. The EMI is produced by current passing through the core strand creating a magnetic field.




As shown in

FIG. 6

, the magnetic field


40


is emitted according to the Right-Hand Rule: the right thumb is pointed in the direction of the current


41


, and the fingers are curled—indicating the direction of the magnetic field. However, one advantage of the present invention is that the substantially parallel spiral-wound wires


15


emit magnetic field energy towards each other, thereby substantially canceling each other and minimizing EMI. Therefore, the current invention is compatible with virtually any engine management system, including EMI and RFI sensitive systems.




Another way to minimize, or eliminate EMI is to use a ferromagnetic material in the core strand


13


. The ferromagnetic material, containing iron, can absorb or modify any EMI generated. On embodiment of the present invention employs a core strand comprising ferromagnetic material, as described above. The core strand carries very high electric currents, and the ferromagnetic material absorbs any EMI generated.




Other Embodiments




Certain preferred embodiments have been described above. It is to be understood that a latitude of modification and substitution is intended in the foregoing disclosure, and that these modifications and substitutions are within the literal scope—or are equivalent to—the claims that follow.




Accordingly, it is appropriate that the following claims be construed broadly and in a manner consistent with the spirit and scope of the invention herein described.



Claims
  • 1. A spark plug cable comprising:a center element structured to communicate electric current from a power source to a spark plug; an insulator surrounding substantially all of the center element; and a conductor surrounding at least a portion of the insulator; wherein the center element, insulator and conductor comprise a capacitor, and wherein the capacitance of the capacitor is adjusted by increasing or decreasing a surface area of the center element.
  • 2. The spark plug cable of claim 1, wherein the maximum capacitance value is determined when the sparking element receives electric current from the current source sporadically.
  • 3. The spark plug cable of claim 1, wherein the safety margin is determined when the sparking element receives electric current from the current source consistently.
  • 4. The spark plug cable of claim 1, wherein the conductor is comprised of a material selected from the group consisting of: conductive materials; copper; tin; brass and steel; and a combination of any one of copper, tin, brass and steel.
  • 5. The spark plug cable of claim 1, wherein the center element has a length between about seven and forty inches.
  • 6. The spark plug cable of claim 1, wherein the conductor is flexible.
  • 7. The spark plug cable of claim 1, further including a spark plug connector and a power source connector coupled to the center element.
  • 8. The spark plug cable of claim 1, wherein the center element is structured to minimize electromagnetic interference.
  • 9. The spark plug cable of claim 1, wherein the center element is comprised of a core strand surrounded by a spiral-wound wire.
  • 10. The spark plug cable of claim 1, wherein the center element is comprised of a material selected from the group consisting of: conducting materials; non-conducting materials; ferromagnetic materials; and non-ferromagnetic materials.
  • 11. The spark plug cable of claim 1, wherein the capacitance of the capacitor is adjusted by:changing a surface area of a center element by selectively increasing and decreasing a distance between a plurality of gaps in a wire that is wound about the center element.
  • 12. The spark plug cable of claim 1, wherein the capacitance of the capacitor is varied by changing a surface area coverage of the spark plug cable by selectively lengthening and shortening a conductor that surrounds at least a portion of the spark plug cable.
  • 13. A method for optimizing an ignition cable configured to carry electric current from a power source to a spark plug, the method of optimizing the ignition cable comprising the steps of:providing an ignition cable comprising a center element, an insulator and a conductor, with the center element, insulator and conductor comprising a capacitor; and adjusting a capacitance of the capacitor by changing a surface area coverage of the ignition cable by lengthening or shortening the conductor that surrounds at least a portion of the ignition cable.
  • 14. The method according to claim 13, wherein the step of adjusting the capacitance of the capacitor is accomplished by increasing a distance between an outer capacitor electrode and an inner capacitor electrode to decrease an electrical charge stored by the capacitor.
  • 15. The method according to claim 13, wherein the step of adjusting the capacitance of the capacitor is accomplished by decreasing a distance between an outer capacitor electrode and an inner capacitor electrode to increase a charge stored by the capacitor.
  • 16. The method according to claim 13, wherein the conductor is comprised of a material selected from the group consisting of: conductive materials; copper; tin; brass and steel; and any combination of any one of copper, tin, brass and steel.
  • 17. The method according to claim 13, wherein the step of adjusting the capacitance of the capacitor is accomplished by:changing a surface area coverage of the ignition cable by selectively increasing and decreasing a plurality of openings located between a plurality of strands of the conductor.
  • 18. A method of optimizing an ignition cable comprising at least a resistor and a capacitor, the ignition cable configured to carry electric current from a power source to a spark plug, the method of optimizing the ignition cable comprising the steps of:determining an available charge from the capacitor; determining an ideal spark duration; and adjusting a resistance of the resistor by changing a length of the ignition cable so that when the electric current is delivered to the spark plug, a spark of ideal spark duration occurs.
  • 19. The method according to claim 18, wherein the spark of ideal spark duration can range from about 40 nanoseconds to about 1000 nanoseconds.
  • 20. The method according to claim 18, further including the step of:suppressing electromagnetic interference generated by the ignition cable.
  • 21. The method according to claim 18, wherein the step of suppressing electromagnetic interference is accomplished by winding a wire about a center element of the ignition cable.
  • 22. The method according to claim 18, wherein the step of suppressing electromagnetic interference is accomplished by winding a wire about a center element of the ignition cable, the center element containing an electromagnetic interference suppressing material.
REFERENCE TO RELATED APPLICATION

This is a continuation-in-part of application Ser. No. 08/823,676, filed Mar. 24, 1997, entitled ENVIRONMENTAL SPARK PLUG-CABLE WITH COAXIAL CD-IGNITION EFFECT, now abandoned, based on Provisional Application Ser. No. 60/027,493, filed Sep. 30, 1996.

US Referenced Citations (49)
Number Name Date Kind
1447812 Otto Mar 1923 A
1756486 Henry Apr 1930 A
1902541 Brown et al. Mar 1933 A
2129472 Lysholm et al. Sep 1938 A
2173766 Ramsey Sep 1939 A
2376362 Kasarjian May 1945 A
2378893 Berkey et al. Jun 1945 A
2415138 Kasarjian Feb 1947 A
2459855 Wall Jan 1949 A
2640174 Short et al. May 1953 A
2904723 Altrogge et al. Sep 1959 A
2927248 Ramsay Mar 1960 A
2939905 Canifield Jun 1960 A
3045148 McNulty Jul 1962 A
3324347 Brugnola Jun 1967 A
3336506 Frank Aug 1967 A
3361932 Campbell Jan 1968 A
3649876 Mandock et al. Mar 1972 A
3683232 Baur Aug 1972 A
3842819 Atkins et al. Oct 1974 A
4082980 Yoshikawa et al. Apr 1978 A
4103276 Kennon et al. Jul 1978 A
4122816 Fitzgerald et al. Oct 1978 A
4123688 Yoshikawa et al. Oct 1978 A
4223656 Hamley Sep 1980 A
4324219 Hayashi Apr 1982 A
4333125 Hensley et al. Jun 1982 A
4333126 Hensley et al. Jun 1982 A
4402036 Hensley et al. Aug 1983 A
4506235 Mayer Mar 1985 A
4510468 Mayer Apr 1985 A
4549114 Herden Oct 1985 A
4589398 Pate et al. May 1986 A
4590536 Gerry May 1986 A
4613789 Herden et al. Sep 1986 A
4631451 Anderson et al. Dec 1986 A
4636690 Herden et al. Jan 1987 A
4658185 Albrecht et al. Apr 1987 A
4727891 Schmidt et al. Mar 1988 A
4746834 Bauerle et al. May 1988 A
4751430 Muller et al. Jun 1988 A
4824385 Sturdevan Apr 1989 A
4841259 Mayer Jun 1989 A
5012125 Conway Apr 1991 A
5376886 Shimasaki et al. Dec 1994 A
5397860 Yochum et al. Mar 1995 A
5593524 Philips Jan 1997 A
5716223 Phillips, Jr. et al. Feb 1998 A
5866843 Ikeda Feb 1999 A
Provisional Applications (1)
Number Date Country
60/027493 Sep 1996 US
Continuation in Parts (1)
Number Date Country
Parent 08/823676 Mar 1997 US
Child 09/535781 US