A combustion initiation system includes an initiating device for producing, containing and propelling a combustion initiating plasma having an energy density approaching that produced by combustion of the fuel itself, and is suitable for initiating combustion in relatively lean mixtures of various types of fuels. A high voltage power supply delivers electrical energy by a coaxial cable to the initiating device which communicates with a fuel mixture in a combustion area such as the combustion chamber of an ordinary internal combustion engine. The initiating device includes a capacitive portion for storing a large quantity of electrical energy therein derived from the power supply, and an electrode portion integral with the capacitive portion which comprises a pair of concentric, rod shaped electrodes for producing a high energy, umbrella shaped plasma discharge, using the inverse pinch technique. Due to the close proximity between the capacitive and electrode portions of the initiating device, rapid energy transfer from the former to the latter creates high magnetic pressures which transform the discharge into a high energy plasma jet which is delivered well into the combustion area.
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1. A device for generating a high energy plasma jet for initiating combustion of fuel, comprising:
a first electrode including a rod shaped member and a tip on one extremity of said rod shaped member; and a second electrode electrically insulated from said first electrode and including an annular portion circumscribing the longitudinal axis of said rod shaped member, said tip being substantially spaced along said longitudinal axis from said annular portion of said second electrode, said tip and said annular portion defining an annular space therebetween across which electrical current may flow to produce an annularly shaped electrical discharge for initiating combustion of said fuel, the longitudinal spacing between said tip and said annular position portion being sufficient to allow said discharge to generate a generally cylindrical an electromagnetic field surrounding said discharge and sufficient in strength to temporarily radially confine for urging said discharge radially outward from said longitudinal axis; and means continuous with said first and second electrodes for temporarily storing a quantity of electrical energy therein sufficient to produce said electrical discharge, said device having an inherent inductance sufficiently low to result in the discharge of the stored quantity of electrical energy across said annular space within 60 nanoseconds .
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plasma jet for initiating combustion of said fuel. 14. The device of claim 13 1, wherein said storing means comprises a capacitor having a pair of spaced-apart, electrical storage plates, one of said plates being contiguous to and coupled with said one electrode, the other of said pair of plates being contiguous to and coupled with said second electrode. 15. The device of claim 14 wherein said pair of electrical storage plates have a dielectric material interposed therebetween, said dielectric material being selected from the group consisting of ceramic, water, oil, glycerene, or isopropyl alcohol. 16. The device of claim 15, wherein said rod shaped member is disposed between said tip and said pair of capacitor plates, and each of said capacitor plates of said pair thereof are of generally star shaped cross section. 17. The device of claim 14, wherein said one capacitor plate of said pair thereof is connected to the opposite extremity of said rod shaped member. 18. The device of claim 1, including a layer of electrically insulative material surrounding the cylindrical sidewalls of said rod shape shaped member and interposed between said annular portion of said second electrode and said rod member. 19. The device of claim 18, wherein said tip is essentially circular in cross section, the circular periphery of said tip extending radially outward beyond the cylindrical sidewalls of intermediate sections of said rod member, whereby the diameter of said tip exceeds the diameter of said intermediate sections of said rod member. 20. The device of claim 19, wherein the outside diameter of said layer of insulative material is less in magnitude than the diameter of said tip. 21. An improved device for initiating combustion of fuel in a combustion chamber using a high energy plasma jet, comprising: first and second electrodes communicating with said combustion chamber and defining a an annular discharge gap therebetween across which a preselected quantity of electrical energy may be transferred, said preselected quantity of electrical energy being sufficient in magnitude to produce a high energy plasma jet resulting in the initiation of combustion of said fuel, said first and second electrodes being configured to produce a generally cylindrical a current flow which creates an electromagnetic field for radially confining the transfer of electrical energy between said electrodes during said transfer; urging the transfer of electrical energy between said electrodes radially outward; and, means contiguous with said first and second electrodes and immediately adjacent said combustion chamber for temporarily storing a said preselected quantity of electrical energy therein sufficient in magnitude to create said high energy plasma jet, said storing means being adapted for electrically coupling with a source of electrical power and electrically connected with each of said first and second electrodes, said device having an inherent inductance sufficiently low to result in the discharge of said preselected quantity across said discharge gap within 60 nanoseconds. 22. The device of claim 21 wherein: said first and second electrodes are concentrically disposed with respect to each other about a longitudinal axis, said second electrode being annular in shape and circumscribing portions of said first electrode, said first electrode being elongate and including a tip portion on one end thereof, said tip portion being spaced from said second electrode along said longitudinal axis, said discharge gap being defined by an annular space surrounding said first electrode between said tip portion and said second electrode. 23. The device of claim 22, wherein said tip portion is essentially circular in cross section and the periphery of said tip portion extends radially outward from said longitudinal axis beyond the longitudinal sidewalls of said first electrode. 24. The device of claim 23, wherein said second electrode forms an annular cavity surrounding essentially the entire length of said first electrode. 25. The device of claim 24, wherein said annular cavity is dish shaped. 26. The device of claim 22, wherein said second electrode extends radially outward from said longitudinal axis, the interior perimeter of said second electrode being radially spaced from said first electrode. 27. The device of claim 22, including a layer of electrical insulative material surrounding at least parts of said first electrode including said portions thereof and extending from said tip portion toward the other end of said first electrode. 28. The device of claim 21, wherein said first electrode is essentially cylindrical in shape. 29. The device of claim 28, wherein said first electrode includes a bore extending longitudinally therethrough. 30. The device of claim 21 wherein said storing means comprises a capacitor including a pair of spaced apart electrical energy storage plates respectively coupled with said first and second electrodes. 1. The device of claim 30, wherein each of said storage plates is essentially star shaped in cross-section. 32. The device of claim 30, wherein said pair of storage plates are each symmetrically disposed about said longitudinal axis. 33. The device of claim 32, wherein said first electrode includes a tip portion on one end thereof distal from said second electrode, said tip portion being generally conical in shape. 34. The device of claim 32, wherein said pair of storage plates are respectively formed integral with said first and second electrodes. 35. A system for sequentially initiating combustion of a plurality of predefined quantities of fuel, comprising: high voltage generating means adapted to be operably coupled with a source of electrical energy for producing a high electrical voltage; electrical energy storage means operably coupled with said high voltage generating means for storing a predetermined quantity electrical energy; a plurality of combustion initiation devices respectively associated with said plurality of said predefined quantities of fuel and spaced distal from said energy storage means, each of said devices including a capacitive portion for storing said predetermined quantity of electrical energy therein and an electrode portion formed integral with said capacitive portion, each said devices being operable to discharge said predetermined quantity of electrical energy through said electrode portion within approximately 60 nanoseconds, said predetermined quantity of electrical energy being sufficient in magnitude to produce a high energy plasma jet for initiating combustion of the corresponding quantity of fuel, the electrode portion of each of said devices comprising a first electrode including a rod shaped member having a tip on one end thereof and a second electrode electrically insulated from said first electrode and including an annular portion circumscribing the longitudinal axis of said rod shaped member, said tip being substantially spaced from said annular portion, said tip and said annular portion defining an annular space therebetween across which electrical current may be transferred to produce an annularly shaped electrical discharge, the longitudinal spacing between said tip and said annular portion being sufficient to allow said discharge to generate a generally cylindrical an electrical current flow producing an electromagnetic field enveloping said discharge, said field being sufficient in strength to temporarily radially restrain said discharge whereby to increase the energy density of said discharge for moving said discharge, said predetermined quantity of electrical energy being sufficient to produce said magnetic field; and timing control means operably coupled with said electrical energy storage means and with each of said initiation devices for selectively coupling said electrical energy storage means with said initiation devices in a predetermined timed sequency sequence whereby to sequentially deliver said predetermined quantity of electrical energy from said storage means to individual ones of said capacitive portions of said initiation devices. 36. The system of claim 35, wherein: said second electrode is disposed concentric with respect to said first electrode about said longitudinal axis, and said first electrode includes a layer of electrically insulative material covering said rod shaped member and extending between said tip and said annular portion of said second electrode. 37. The system of claim 36, wherein said rod shaped member is essentially circular in cross section, the diameter of said tip being greater in magnitude than the diameter of intermediate sections of said rod shaped member between said tip and said annular portion of said second electrode. 38. The system of claim 37, wherein said tip is generally conical in shape. 39. The system of claim 36, wherein said annular portion of said second electrode extends radially outward from said longitudinal axis, the inner periphery of said annular portion being spaced from the longitudinal sidewalls of said rod shaped member. 40. The system of claim 36 wherein said insulative material is selected from the group consisting of glass or ceramic. 41. The system of claim 35, wherein said capacitive portion of each of said devices comprises a pair of electrically conductive, spaced apart plates defining a capacitor and respectively contiguous with said first and second electrodes. 42. The system of claim 41, wherein each of said plates is symmetrically disposed about said longitudinal axis, said plates being respectively electrically connected to said annular portion of said second electrode and to the opposite extremity of said rod shaped member. 43. The system of claim 41, including a layer of dielectric substance interposed between said plates. 44. The system of claim 43, wherein said dielectric substance is one selected from the group consisting of water, oil, glycerine, isopropyl alcohol or ethylene glycol. 45. The system of claim 41, wherein each of said plates comprises a plurality of sections, each of said sections extending essentially radially outward from said longitudinal axis. 46. The system of claim 35, wherein said high voltage generation means is capable of producing an output of at least approximately 15,000 volts. 47. The system of claim 35, where said high voltage generating means comprises a pulse type voltage generator. 48. The system of claim 35, wherein said high voltage generating means includes an output for delivering high voltage electrical energy thereto, said storage means being electrically coupled to said output of said generating means, said timing control means comprising: distribution circuit means coupled with each of said initiation devices and with said storage means for selectively distributing electrical energy from said storage means to the corresponding one of said initiation devices. 49. The system of claim 48, wherein distribution circuit means comprises a plurality of electrical circuits respectively associated with said initiation devices, each of said circuits comprising an electronic switch connected between said storage means and the respectively associated initiation device, and an electronic trigger operably coupled with said switch for controlling the latter. 50. The system of claim 49, wherein said timing control means further includes: first control means operably coupled with said storage means for controlling the discharge of electrical energy stored in said storage means from the latter to said distribution circuit means, and second control means operably coupled with said first control means and with each of said electrical circuits for selectively delivering a control signal simultaneously to a selected one of said electrical circuits and to said first control means. 51. The system of claim 50, wherein said first control means comprises a pair of spaced apart electrical terminals defining a spark gap therebetween and a third electrical terminal coupled with said second control means for inducing electrical breakdown of the medium between said pair of electrical terminals. 52. The system of claim 50, wherein said second control means comprises: a first electrical terminal adapted to be coupled with a source of electrical power, a plurality of electrical terminals respectively coupled with said electrical circuits, and means for selectively coupling said first electrical terminal with one of said plurality of electrical terminals. 53. The system of claim 50, wherein said timing control means further includes an inductor operably coupled between said first and second control means. 54. The system of claim 35, wherein said high voltage generating means is provided with an input and there is further provided: a source of electrical power operably coupled with said high voltage generating means. 55. The system of claim 54, wherein said source of electrical energy comprises a battery and means operably coupled with said battery for recharging the latter. 56. The system of claim 35, including a coaxial electrical cable operably coupled between each of said initiation devices and said timing control means, said cable comprising an inner and outer conductor, said inner and outer conductors being operably coupled with the capacitive portion of the corresponding initiation device.
PAR 7. Apparatus for initiating combustion of fuel, comprising:
first and second electrodes defining a gap across which a preselected quantity of electrical energy may be discharged, the magnitude of said preselected quantity of electrical energy being sufficient to form a high energy plasma for initiating combustion of said fuel; and capacitor means substantially contiguous with said first and second electrodes for storing said preselected quantity of electrical energy, the inductance of said electrodes and said capacitor means being sufficiently low to allow said preselected quantity of electrical energy to be discharged across said gap within 60 nanoseconds. 58. The apparatus of
10 microseconds. 62. The apparatus of claim 58, wherein said preselected quantity of electrical energy stored in said capacitor means produces an electrical current through said electrodes sufficient in magnitude to create an inverse pinch electrical discharge across said gap and between said electrodes, and to develop a magnetic pressure for moving said discharge radially outward from said axis, the quantity of said electrical current being given by ##EQU5## 63. A device for initiating combustion of a gaseous air-fuel mixture in a combustion chamber using a high energy plasma, comprising: first and second electrodes symmetric about a reference axis and defining an electrical discharge gap; and means coupled with said electrodes for storing a preselected quantity of electrical energy sufficient in magnitude to produce an electrical discharge between said electrodes across said gap, said discharge resulting in the initiation of combustion of said gaseous air-fuel mixture, said electrodes and said storing means defining an electrical discharge circuit in said device, said discharge circuit having an inherent inductance and being configured to minimize said inherent inductance and thereby maximize the magnitude of magnetic power generated by the current flowing in said discharge circuit, the inherent inductance of said discharge circuit being sufficiently low to result in the transfer of preselected quantity of electrical energy from said storing means to the electrical discharge in less than approximately 60 nanoseconds. 64. The device of claim 63, wherein: said first and second electrodes and said discharge gap are coaxial, said discharge gap being annular in shape and extending longitudinally along said axis, said preselected quantity of electrical power and said magnetic power being sufficient in magnitude to create an inverse pinch electrical discharge between said electrodes across said gap. |
This invention generally deals with combustion of fuels, especially in internal combustion engines, and relates more particularly to a device implemented method of improving combustion using high energy plasma initiation techniques.
Conventional internal combustion engines, such as those used in motor vehicles, have long employed spark producing systems for initiating combustion of fuels within combustion cylinder chambers. Although "spark plug" type devices for initiating fuel combustion have gained almost universal use in the past, it has been known that these devices were not particularly efficient in maximizing fuel combustion, hence, additional fuel was required to achieve a desired level of power output; moreover, incomplete fuel combustion resulted in the production of air pollutants which had to be dealt with. In order to assure satisfactory operation, prior art spark plug devices have required that the spark discharge produced thereby communicate with a region within the combustion chamber where an optimum (stoichiometric) fuel-to-air mixture exists, since the resulting energy density of combustion from a stoichiometric region within the chamber is usually high enough to ensure that the remainder of the fuel achieves combustion. Inasmuch as the energy produced by the spark discharge is insufficient to induce combustion of fuel-to-air mixtures which are not stoichiometric, richer mixtures of fuel to air were required in the past in order to assure that the spark discharge reached a stoichiometric region within the combustion chamber. However, due to the limited volume within the chamber which might be reached by a spark discharge, stoichiometric values of fuel to air mixtures could not always be provided under cold starting, idling, or part load operating conditions.
Because of the problems discussed above related to the relatively low energy produced by spark discharge systems, numerous attempts have been made in the past to increase the energy delivered by the spark discharge, and various prior art spark plug improvements are alleged to yield a "hotter spark", but none of such prior art spark plug devices are in fact capable of delivering the level of power needed to produce relatively complete combustion of fuel to air mixtures which are less than stoichiometric.
Ignition devices for producing an ignition plasma, such as that disclosed in U.S. Pat. No. 3,842,818, have been devised in an effort to increase the level of energy delivered to the fuel to air mixture, but the energy levels achieved by these plasma producing devices have not been sufficient to initiate combustion in fuel-to-air mixtures which are relatively far from stoichiometric, and therefore achieved satisfactory results only when a stoichiometric region of such fuel-to-air mixture was in proximity to the ignition plasma.
Another prior art attempt at solving the problem involves providing a combustion chamber physically configured to produce stratification of the fuel-to-air therewithin, whereby the richer mixtures are produced mixtures in a region immediately adjacent a conventional spark discharge initiating device, thereby assuring that the initiating spark reaches a region of fuel-to-air mixture which is close to stoichiometric.
The present invention provides a combustion initiation system which includes an initiating device that produces an initiation plasma with an energy density comparable to that produced by combustion of the fuel in the chamber, in order to initiate combustion in fuel-to-air mixtures which are relatively far from stoichiometric, thereby allowing the use of leaner fuel-to-air mixtures for improving operating economy while also reducing hydrocarbon emissions. The initiation system also includes a high voltage pulsed power supply for delivering electrical energy by means of a coaxial cable to the initiating device which communicates with the combustion chamber. The initiating device includes a capacitive portion for storing alarge quantity of electrical energy therein derived from the pulsed power supply and an electrode portion coupled to the capacitive portion which comprises a pair of concentric electrodes for producing a high energy plasma discharge, using the inverse pinch technique. The discharge is transformed by high magnetic pressures into chargeis It is not necessary to provide side walls circumscribing the tip portion of the device as shown in the embodiments of FIGS. 3 and 4 in many applications. The walls surrounding the tip do serve to desirably reduce the overall resistance of the discharge circuit, however, the need to employ such sidewalls to achieve optimum results will be governed by numerous design considerations involved in a specific application.
Attention is now directed to FIGS. 11 and 12, wherein an initiation system is depicted employing the initiating device forming a part of the present invention, which is particularly suited for use with a conventional internal combustion engine, such as that used in automobiles.
As disclosed in FIG. 11, the initiating system is particularly adapted for use with a four cylinder engine, however, as will become apparent later, the invention is equally suitable for use with an engine having any number of combustion chambers. Broadly, the initiating system comprises a primary power source indicated within the broken line 134, a high voltage pulse generator 136, an essentially conventional electrical distributor diagrammatically represented by the numeral 138, a spark gap device 140, a standard ignition coil 142, a high energy storage capacitor 144, and a plurality of electronic distribution circuits, each indicated in block form by the numeral 146 in FIG. 11, and shown in more detail in FIG. 12.
Power source 134 comprises an ordinary 12 or 24 volt storage battery 148 coupled in parallel relationship with a conventional charging device 150, such as an alternator mechanically driven by the automobile's engine, and is further coupled with a pair of output lines 152 and 154. The high voltage pulse generator 136 derives power from the power source 134 via branch lines 156 and 158 which are respectively connected to output lines 152 and 154. Each of the inputs of distribution circuits 146 are likewise coupled across the output lines 152 and 154 and in parallel relationship to the high voltage pulse generator 136 by distribution lines 160 and 162. The input of distributor 138 is coupled to the power source 143 by line 164. Distributor 138 is conventional in design and includes an output terminal corresponding to each of the four engine cylinders, which are operably coupled to corresponding output lines 166 which lines are respectively coupled to the trigger inputs of respectively corresponding ones of electronic distribution circuits 146. Each of the output lines 166 is also respectively coupled through corresponding diodes 174 to line 182 which forms the input of ignition coil 142. Ignition coil 142 may comprise a coil of conventional design ordinarily employed in automobile engine electrical systems, or may be alternately comprise a shunt type inductor, since such coil merely functions in the present application as a means of controlling the timing of the delivery of electronic pulses, rather than to initiate firing as in conventional designs. The output of coil 142 is coupled by line 184 to the trigger terminal 186 of the spark gap device 140.
Spark gap device 140 comprises an enclosed, pressure tight housing of a suitable geometric configuration, such as a cylinder, and is filled with a suitable gas, such as air which is pressurized above the atmospheric pressure level. Spark gap device 140 further includes first and second spaced apart electrodes 188 and 190 respectively forming an air gap therebetween located proximal to the trigger terminal 186. Terminal 190 is coupled to ground 192, while terminal 188 is coupled via line 194 to the negative output line 196 of the high voltage pulse generator 136, the positive output line 198 of the latter mentioned generator being connected to ground 200.
High voltage pulse generator 136 may comprise a conventional design of the SCR power converter type having a constant SCR trigger voltage of approximately 15,000 to 50,000 volts, and will be designed to charge the high voltage storage capacitor 144 to approximately 30 to 40 KV at a repetition rate of approximately 10 pulses per second. High energy storage capacitor 144 may be of a ceramic construction and will preferably have a rating of approximately 100 KV to assure long life and reliability. One plate of the storage capacitor 144 is coupled with the combination of the pulse generator 136 and spark gap device 140 while the other plate of capacitor 144 is coupled in series with each of the electronic distribution circuits 146 by line 202. One side of a resistor 204 is coupled with line 202 between capacitor 144 and circuits 146, while the other side of resistor 202 is coupled to ground 206.
Each of the electronic distribution circuits 146 has a pair of input lines 208 and 210 respectively coupled to the distribution lines 162 and 160 thereby placing each of the circuits 146 in parallel relationship with each other. The distribution circuits 146 each essentially comprise a variable time, power one-shot multivibrator of a conventional design such as that shown in IEEE, volume 12:7, pages 25 and 26.
Referring momentarily now to FIG. 12 in particular, the distribution circuit 6 includes an SCR 212 (silicon controlled rectifier) having its anode coupled through a diode 214 to line 208 while its gate is coupled to line 166. One main terminal of a TRIAC 216 is coupled through resistors 218, 220 and capacitor 222 between line 202 and line 224 which forms the ground portion 224 of a circuit connecting each of the initiating devices (schematically indicated within the broken lines 226 in FIG. 11). The other main terminal and the gate of TRIAC 216 are respectively coupled through resistors 228 and 230 to line 202 and the ground portions 224. The input line 210 is coupled to the cathode of SCR 212, while a capacitor 232 is connected between input line 210 and the gate of TRIAC 216. A high voltage delivery line 234 is connected to line 202 and forms the high voltage portion of a coaxial cable coupling the distribution circuit 146 with the corresponding initiating devices 226 which communicates with the corresponding engine cylinders.
As shown in FIG. 11, each of the initiating devices 226 comprises a capacitive portion indicated by the capacitor 236, a high voltage electrode 238, a ground electrode 240 and a spark gap between electrodes 238 and 240 indicated at 242.
Turning now to a description of the operation of the initiation system, power is delivered from the power source 134 to the distributor 138 as well as to the pulse generator 136, via output lines 152 and 154. The high voltage pulse generator has a direct current output of approximately 5 milliamps and charges the storage capacitor 144 to approximately 50 KV. Voltage in line 164 is selectively coupled to the output lines 166 of the distributor 138 in a predetermined, timed sequence in the ordinary manner. As the automobile's engine mechanically rotates a rotor within the distributor 138, lines 166 are sequentially coupled with line 164, and the resulting firing signal is delivered through line 182 to the ignition coil 142 which functions in the present invention to impose a time delay on the delivery of such signal to the trigger terminal 186; the values of the various components will be selected in a manner such that the capacitor 144 is charged to the desired level prior to the delivery of a firing signal to the terminal 186.
Assuming now that the capacitor 144 is fully charged and one of the initiating devices 226 is about to be fired, a control signal delivered to trigger terminal 186 induces breakdown of the spark gap 187 within the spark gap device 140, thereby producing a firing spark between terminals 188 and 190 which couples the capacitor 144 to the ground 192. At this point, the capacitor 144 discharges into line 202 with a resulting current flow being delivered to each of the distribution circuits 146 and the corresponding high voltage delivery lines 234. Simultaneously with the charging of capacitor 144, the firing signal produced by distributor 138 is delivered by one of the output lines 166 which have been energized and corresponds to the cylinder to be fired, to the trigger of SCR 212. SCR 212 then functions to activate the TRIAC 216 which is operative to couple the ground portion 224 associated with the cylinder about to be fired to ground potential through line 244, thereby permitting the storage capacitor 144 to release energy stored therein through the high voltage line 234 of the cylinder about to be fired. Energy delivered through line 234 is delivered to the capacitive portion 236 of the initiating device 226. When the capacitive portion of 236 of the initiating device 226 is charged to a prescribed level, which charging is completed within approximately 1.5 microseconds, electrical breakdown occurs in the gap 242 resulting in the discharge of the capacitive portion 236 which fires the device 226 by producing a plasma jet that initiates fuel within the cylinder to be fired.
From the foregoing, it is apparent that the initiating device and initiation system of the present invention not only provide for the reliable accomplishment of the object of the invention but do so in a particularly simple yet highly effective manner. It is to be understood that the initiating device of the present invention may be employed in numerous applications for initiating the combustion of various types of fuels, including nuclear fuels. Those skilled in the art may make various modifications or additions to the preferred embodiment chosen to illustrate the invention without departing from the gist and essence of the present contribution to the art. Accordingly, it is to be understood that the protection sought and to be afforded hereby should be deemed to extend to the subject matter claimed and all equivalents thereof fairly within the scope of the invention.
Hensley, George H., Hensley, Raymond E.
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Executed on | Assignor | Assignee | Conveyance | Frame | Reel | Doc |
Mar 17 1988 | HENSLEY PLASMA PLUG, HDI | UNITED STATES OF AMERICA, AS REPRESENTED BY THE DEPARTMENT OF THE TRESSURY, INTERNAL REVENUE SERVICE | SIEZURE OF SAID PATENT BY SAID ASSIGNEE FOR NON PAYMENT OF DELIQUENT TAXES, PURSANT TO AUTHORITY CONTAINED IN SECTION 633, OF THE INTERNAL REVENUE CODE EXECUTION DATE: 3-17-88 | 004856 | /0126 | |
Aug 04 1994 | HENSLEY, GEORGE | Hensley Plasma Plug Partnership | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 007090 | /0152 | |
Aug 04 1994 | HENSLEY, RAYMOND E | Hensley Plasma Plug Partnership | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 007090 | /0152 | |
Sep 26 1995 | Hensley Plasma Plug Partnership | SEPTIMA ENTERPRISES, INC | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 007779 | /0903 |
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