Abstract: A sparking plug cap for internal combustion engines which is made of a resin selected from the group consisting of an alloy of polyphenylene sulfide and polyphenylene oxide, polyarylate, polyether imide and a liquid crystalline polymer, which sparking plug cap is excellent in insulation durability at a high temperature, particularly under a high humidity or in the presence of water.

Abstract: A large discharge-volume spark plug for providing self-limiting microdischarges. The apparatus includes a generally spark plug-shaped arrangement of a pair of electrodes, where either of the two coaxial electrodes is substantially shielded by a dielectric barrier from a direct discharge from the other electrode, the unshielded electrode and the dielectric barrier forming an annular volume in which self-terminating microdischarges occur when alternating high voltage is applied to the center electrode. The large area over which the discharges occur, and the large number of possible discharges within the period of an engine cycle, make the present silent discharge plasma spark plug suitable for use as an ignition source for engines. In the situation, where a single discharge is effective in causing ignition of the combustible gases, a conventional single-polarity, single-pulse, spark plug voltage supply may be used.

Abstract: A Double Sliding Spark Plug as a Volume Ignition System for Internal Combustion Engines causes ignition processes of the air-fuel mixture by two simultaneously conical or cylindrical sliding discharges between a conical or cylindrical high voltage electrode (1) located inside two solid insulation parts (4) and (5) and two circular low voltage electrodes (2) and (3). Those sliding discharges are on outer large conical or cylindrical surfaces of insulation parts (4) and (5) with high diameters. The outside low voltage electrode (2) is connected to a metallic body of this spark plug and to the outer conical or cylindrical surface of the outside insulation part (4). The inside cylindrical or conical low voltage electrode (3) is connected to the inner conical or cylindrical surface of the inside insulation part (5).

Abstract: A spark plug with integral electrical components for producing a spark with an increased size and a larger resulting flame kernel in an internal combustion engine. One or more coils may be built into the spark plug for creating a magnetic field in the vicinity of the spark. This magnetic field has the effect of bending and rotating the spark in a circular motion. Also, a capacitor may be incorporated into the spark plug to increase the intensity of the spark. A method of producing such a spark plug utilizes a cermet ink applied to the ceramic spark plug insulator before the insulator is completely hardened. The cermet ink may be used to create monolithic spark plug electrodes, integrated coils and integrated capacitors. The method may also be used to create monolithic electrically conductive paths through any solid dielectric material.

Abstract: An improved low voltage igniter of the type having an annular spark gap between a center electrode and annular ground electrode which is arranged coaxial with the center electrode. The spark gap is shunted by an insulator surface. Semiconducting material is deposited on the insulator surface as one or more rings which are coaxial with and spaced from the electrodes. The semiconducting rings reduce the voltage required to initiate a spark across the spark gap.

Abstract: A spark plug is disclosed having a metal body 18, a center electrode 16 and an insulator 14 surrounding the center electrode, the part of the insulator disposed within the combustion chamber being separated by an annular gap from the metal body of the spark plug. In order to reduce cycle to cycle variations, a filler 12 of very poor thermal conductivity is used to fill the gap between the insulator 14 and the body 18 to prevent gas movement in this gap, thereby preventing the gap from forming part of the combustion chamber.

Abstract: The invention relates to a method and to a device for improving the dische regime of an electric arc produced between two electrodes. The device is characterized in that it includes means an insulating element (32), preferably spherical in shape, for increasing the resistance to the passage of the electric arc (A) between ends of the electrodes (12, 14). By using the invention it is possible to obtain an arc discharge of the critically damped type. The method and the device are preferably used in shock wave generator apparatus for hydraulic lithotripsy.

Abstract: A spark plug with a surface discharge section for internal combustion engines comprising an insulation body having an inner cavity for receiving a mass of an electrically conductive material, and a bore extending from the inner cavity and through which extends a central electrode which is formed integral with the surface discharge surface, is made of an electrically non-conductive material, and has on an outer surface thereof in the area of the mass and the bore an electrically conductive film, and, in the area defining the surface discharge section a film having no intrinsic conductivity after sintering.

Abstract: A spark plug has a center electrode and a side electrode made of an iron-base, heat resistant (iron, chromium, aluminum, rare earth) alloy. Each electrode has a precious metal insert of a composition that thermally matches the base alloy of the electrodes. The electrodes are made by a method which coats the electrodes with a protective coating to reduce operational oxidation and lead/oil deposit degradation of the interface between such iron based heat resistant alloys and an insert button in the center and side electrodes so as to extend the spark plug's life.

Abstract: A spark plug with creepage spark gap for internal combustion engines includes a plug housing having an annular side electrode, an insulator, surrounded by the plug housing over a longitudinal section, and a central electrode. The layer lies in a through-bore of the insulator and is exposed on the combustion chamber end side. The creepage spark gap is formed between the central electrode and the side electrode along a slideway on the surface of the insulator. To achieve a small plug capacitance with high-dielectric slideway, the insulator has, at least at the end section on the combustion chamber side, at least two coaxial material layers, having very different dielectric constants. These coaxial layers lie or partially lie against each other in a radial direction of the spark plug.

Abstract: A wear indicator for an igniter of the type having a center electrode, an annular ground electrode surrounding the center electrode, and a spark gap between the electrodes extending along a surface of a ceramic material. An annular wear indicating groove is formed in the ground electrode to indicate when the ground electrode is sufficiently eroded to necessitate replacement of the igniter. For a low voltage igniter the ceramic material at the spark gap is a semiconductor material which also is subject to erosion during use. A wear indicating groove also may be formed on the center electrode at a location which becomes exposed to indicate when the semiconductor material is sufficiently eroded to necessitate replacement of the igniter.

Abstract: In a spark plug with combined surface and air spark paths comprising a center electrode, and insulator which surrounds the center electrode and which, at least in the end region of the center electrode, maintains a gap with respect thereto, and a ground electrode which, together with the spark plug body, surrounds the insulator and which at least in the end region of the insulator maintains a gap with respect thereto, the insulator, to form a discharge chamber surrounding the end portion of the center electrode, extends in the axial direction of the plug beyond the center electrode, and the ground electrode encompasses the insulator around the end thereof with an extension of the ground electrode extending into the discharge chamber with a clearance gap being maintained between the extension and the end portion of the insulator.

Abstract: A spark plug for an internal combustion engine which utilizes an annular round ring surrounding the center electrode. Surrounding the center electrode is a fire hole which includes an enlarged annular space to achieve an increased volume of the fire hole to maximize the ignition of the fuel/air mixture within the fire hole. The ground ring may include a series of ports to facilitate dispersement from the spark plug of the ignited fuel/air mixture within the fire hole.

Abstract: The prevention of electrode material erosion by undercutting in the outer electrode shell of igniter electrodes of jet engine ignition systems is prevented by the application of an electrical insulation coating. The coating is applied to the surface of the outer electrode shell which faces the ceramic insulation around the center electrode where erosion patterns are known to occur. The insulation material is selected from electrical insulation substances such as oxides of aluminum, tungsten, magnesium, beryllium or zirconium by choosing a non-porous electrical insulating substance with thermal expansion characteristics approximately equalling those of the outer electrode shell. Since a typical outer electrode shell is composed of 446 stainless steel, an optimum choice for the electrical insulation coating is AL.sub.2 O.sup.3 deposited with a coating thickness of between 5 and 10 mils.

Abstract: A small-sized spark plug for internal combustion engines is disclosed which is composed of a center electrode having a shaft portion surrounded by an insulator layer and a terminal end portion adapted to act as a spark generation portion; and an earthed electrode having a terminal end portion which is spaced apart from and is opposite to the terminal end portion of the center electrode so that a spark gap is defined along a surface of the insulator layer. The shortest distance .delta. (mm) between each end portion of the two electrodes and the surface of the insulation layer and the distance l between the forward end portions of the two electrodes have the following relationship:.delta..gtoreq.0.25 l, and 0.8 mm.ltoreq.l.ltoreq.2.0 mm.A recessed portion may be provided on the surface of the insulation layer.

Abstract: To reduce erosion of a platinum-containing electrode layer (3, 14) applied to the end face of the center insulator (1, 11) of the spark plug, a protective layer of ceramic, preferably aluminum oxide, is applied over the electrode. The aluminum oxide protective is sufficiently thin to permit arc-through or spark-through of the spark from a counter electrode (9, 19). This permits reduction of the thickness of the electrode layer to between about 5 to 15 micrometers, preferably about 8 to 10 micrometers, with a thickness of the protective layer of between 5 to 50 micrometers, preferably about 8 to 10 micrometers. Aluminum oxide is the preferred material for the center insulator, the protective layer, as well as an additive to the center electrode if it is made of a mixture of platinum and ceramic.

Abstract: The invention relates to a spark plug (1) comprising at least two insulated electrodes (5) and (6), an earthed electrode (7) and a chamber (4) so arranged with respect to one another that when a voltage is applied arcs are struck in series between electrodes (7) and (6) and (6) and (5) to provide a continuous plasma jet expelled from the chamber (4) at low energies (<100 mJ) and which can be used for combustion of a lean air/fuel mixture.

Abstract: A spark plug for an ignition system has a ring gap between two electrodes. A first electrode has a ring shape defining a central opening. A second electrode is positioned within the central opening of the first electrode. An insulating material is positioned between the first and second electrodes so as to provide a surface for a spark path between the first and second electrodes. The insulating material is spaced from the electrode so as to provide therebetween an air gap for increased sparking.

Abstract: A spark plug for spark ignition type internal combustion engines includes an earth electrode formed of a heat-resisting metal, a central electrode, and a supplementary electrode provided on the earth electrode or the tip end of the central electrode. The supplementary electrode cooperates with one of the other electrodes to define therebetween a spark gap which is smaller in dimension than the normal spark gap defined between the earth and central electrodes. The supplementary electrode has a higher specific resistance than that of the earth electrode.

Abstract: A spark plug having center and ground electrodes. One of the electrodes is covered with an insulator, a part of which includes outer and inner insulating layers. The outer insulating layer is formed of a heat-resistant and high voltage-resistant material. The inner insulating layer is formed of a material having a high dielectric constant and interposed between the outer insulating layer and the portion of the one electrode which is directed toward the other electrode.

Abstract: A spark plug with a wide discharge gap includes an insulating layer formed on one or the other of its center and ground electrodes and disposed in the gap between the electrodes. The insulating layer includes an inner insulating layer of a material having a high dielectric constant and an outer insulating layer of a material having an excellent resistance to heat and high voltage, which surrounds the inner insulating layer, whereby ensuring a reduced discharge voltage, an improved ignition performance and improved heat resistance and durability.

Abstract: A sparkplug having an improved antifouling performance and in which a decrease in insulation resistance is prevented, even if an electrically conductive material is deposited on the firing surface of the insulator of the sparkplug. In accordance with the invention, a coating of flourine oil containing elemental flourine or elemental fluorine plus elemental silicone is formed on at least the surface of the base of the firing leg of the porcelain insulator of the sparkplug surrounded by the inner surface of the combustion chamber side of the metal casing. Further, paraffin may be added to the solution of the coating. The coating may also be formed on the inner surface of the metal casing.

Abstract: A plasma jet ignition plug wherein a film of semiconductor or a semiconductor oxide defines together with a first rod-shaped electrode and a second electrode a plasma cavity.

Abstract: The present invention provides a hot spark that is more-or-less uniform over the combustion chamber volume in a liquid oxidant/liquid fuel combustion engine. In addition, heat losses are reduced and low wear/low friction surfaces are provided. Flame sprayed ceramic coatings are utilized to provide all embodiments of the present invention.

Abstract: An insulating support body, for example an aluminum oxide ceramic, supports two electrodes spaced from each other by a small gap, for example 0.1 mm, which will have therebetween a high resistance. Upon collection of soot, the resistance between the electrodes across the gap will drop, which can be indicated by sensing current through the electrodes upon connection to a source of electrical energy. To remove soot upon termination of smoking, or soot contents in the gases, the electrodes are applied over, or embedded in a layer of essentially non-conducting catalyzing material which, in the presence of oxygen, catalyzes the oxidation of soot located in the gap between the electrodes to thereby remove the soot by oxidation and restore the resistance of the path between the electrodes and hence the sensitivity of the sensor for subsequent detection of accumulation of soot in the gap.

Abstract: A spark plug power enchancer for internal combustion engine comprises a secondary spark gap produced between spaced electrodes separated by a dielectric material formed of a sea shell.