Abstract: To obtain an impact wave by generation of arc discharge between a high-voltage-side electrode 31 connected to a high-voltage-side terminal of a pulse power generating device and a low-voltage-side electrode 32 grounded or connected to a low-voltage-side terminal of the power source. One of the high-voltage-side electrode 31 or the low-voltage-side electrode 32 is an annular electrode formed in an annular shape, the other electrode is a core electrode arranged inside the annular electrode, and arc discharge is generated between an inner peripheral portion of the annular electrode and an outer peripheral portion of the core electrode.

Abstract: A spark plug is provided which includes a hollow cylindrical center electrode disposed inside a metal shell and a ground electrode joined to the metal shell. The ground electrode has an inner peripheral surface facing an outer peripheral surface of the center electrode. At least one of the outer periphery of the center electrode and the inner periphery of the ground electrode has formed therein at least one recess whose ends lies in a center-to-ground electrode facing region where the outer peripheral surface of the center electrode faces the inner peripheral surface of the ground electrode in a radial direction of the center electrode. This decreases voltage required by the spark plug to achieve discharge.

Abstract: A spark plug for internal combustion engines is provided which includes a porcelain insulator which is disposed inside a housing and extends outside a front end of the porcelain insulator. An annular ground electrode is secured to a front end portion of the housing. A pocket is created between a nose of the porcelain insulator and the housing. The housing has formed therein a plurality of vent holes which are located outside the ground electrode in a radial direction of the housing and communicate between the pocket and a combustion chamber of the engine. The vent holes include a first vent hole and a second vent hole which are different in opening area from each other, thereby enhancing scavenging of the pocket to ensure the stability of operation of the spark plug.

Abstract: In some aspects, a spark plug includes a spark gap in an enclosure of the spark plug. The spark plug includes a passage in the interior of the enclosure. During operation of the engine, the passage directs flow through the spark gap, primarily away from a combustion chamber end of the enclosure. The passage can direct flow at a velocity of 5 meters/second or greater.

Abstract: A spark plug includes: a metallic shell having a through hole extending in a direction of an axis; a cap covering an opening in the metallic shell; a melt portion formed between the cap and the metallic shell to join the cap and the metallic shell to each other; and a gap extending from a specific space which is surrounded by the metallic shell and the cap to the melt portion and interposed between the metallic shell and the cap.

Abstract: A spark plug for a prechamber internal combustion engine, having: a body with a passage and a front end; a center electrode located in the passage and that projects past the front end; an insulator that surrounds a section of the center electrode and has a tapering front end that together with the passage forms a free annular space within the body; a ground electrode with an annular ignition section that surrounds a section of the center electrode located outside the body, forming a spark gap; the ground electrode has a mounting section connected to the front end of the body, and at least two web sections connecting the ignition section to the mounting section; located between the web sections are scavenging ports through which the annular space is in connection with the environment outside the spark plug.

Abstract: Spark plug for an internal combustion engine, having a center electrode and a ground electrode arranged in radial direction around the center electrode, wherein an annular spark gap is formed between the center electrode and the ground electrode for igniting a fuel mixture by means of an electric ignition spark developing between the center electrode and the ground electrode, and wherein the ground electrode is contoured in such a way that particles reaching the region of the ground electrode can be removed from the spark gap under the influence of gravitational force.

Abstract: A spark plug includes a tubular housing, a tubular insulator retained in the housing, a center electrode secured in the insulator with a distal end portion of the center electrode protruding outside the insulator, and an annular ground electrode fixed to a distal end of the housing. The housing has, at the distal end thereof, a small-inner diameter portion that has a smaller inner diameter than other portions of the housing. The annular ground electrode is arranged on a distal end surface of the small-inner diameter portion of the housing so that an inner circumferential surface of the ground electrode faces an outer circumferential surface of the distal end portion of the center electrode through a spark gap formed therebetween. The outer diameter of the ground electrode is less than the outer diameter of the distal end surface of the small-inner diameter portion of the housing.

Abstract: A spark plug for an internal combustion engine includes a housing, an insulation porcelain, a center electrode and a ground electrode. Both of a tip portion of the center electrode and an opposing portion of the ground electrode are provided with respective projection portions which are projected toward a spark discharge gap. At least one of the projection portions has an opposing face that confronts the spark discharge gap and is inclined with respect to a plane perpendicular to an axial direction of the plug. The spark discharge gap is configured to be gradually enlarged, in one direction perpendicular to the axial direction of the plug, from a narrow gap on one end side toward a wide gap on the other end side.

Abstract: An ignition plug having a center electrode, a grounding electrode, an insulator, and a metal shell. The center electrode is held by the insulator, and the insulator is held by metal shell. A cavity is formed between the grounding electrode and the center electrode. The grounding electrode is joined to the inner wall surface of the metal shell via a melting portion. In the melting portion, in a predetermined cutting surface MS including a melting deepest point DP and a central axis CX, a percentage ratio MDD of a melting depth MD of the melting portion with respect to a thickness of the grounding electrode is 5% or more, and an area Sm of a portion included in an outer circumferential side of the metal shell is 10% or more of the entire area S.

Abstract: A device for providing ignition of a fuel-air mixture using a transient plasma discharge is provided. The device includes an anode coupled to receive a voltage; and a cathode disposed in proximity to the anode and coupled to a ground, wherein at least one of the anode and the cathode includes a protrusion that enhances an electric field formed between the anode and the cathode, the protrusion forming a sharp edge defining a plurality of points, each point forming a path of shortest distance between the anode and the cathode.

Abstract: A spark plug includes an insulator having a first end, the insulator having a center axis and a center electrode coupled to the insulator and having a center electrode tip extending beyond the first end of the insulator. The spark plug further includes a ground electrode having an end spaced from an end of the center electrode, the ground electrode having a first portion extending substantially parallel to the center axis and a second portion extending at an angle from the first portion and relative to the center axis. A ground electrode tip is disposed on the second portion of the ground electrode, wherein the ground electrode tip is spaced from the center electrode tip. A ring member is operatively connected to the center electrode proximate the center electrode tip.

Abstract: In some aspects, a spark plug includes a spark gap in an enclosure of the spark plug. The spark plug includes a passage in the interior of the enclosure. During operation of the engine, the passage directs flow through the spark gap, primarily away from a combustion chamber end of the enclosure. The passage can direct flow at a velocity of 5 meters/second or greater.

Abstract: A plasma jet ignition plug exhibiting high plasma generation efficiency while restraining occurrence of preignition. P1 represents the position of a rear end of a region of a metallic shell ledge, the region being in contact with an insulator. P2 represents the position of a rear end of a region of the insulator ledge, the region being in contact with the center electrode. Front end surfaces of the metallic shell, the insulator, and center electrode, an imaginary plane S1 which is perpendicular to the axis and contains position P1, and an imaginary plane perpendicular to the axis and contains position P2 are disposed in this order from front side to rear side along the axis. The axial distance A from the front end surface of the insulator to imaginary plane S1 and axial distance B from the imaginary plane S1 to imaginary plane S2 satisfy 0.5×A?B.

Abstract: The invention refers to a prechamber spark plug comprising an ignition electrode with several electrode arms. The ignition electrode is made of a cross-shaped blank that is cut out of sheet metal and then the electrode arms are set upright by bending. The sheet metal is made of iridium or an iridium-based alloy by rolling in a rolling direction and the ignition electrode blank is cut out in such a way that an angle of 50° or less is present between each of the electrode arms and the rolling direction (W).

Abstract: A plasma jet spark plug capable of preventing a channeling progress and having excellent heat conduction. The plasma jet spark plug comprised of: a ceramic insulator having a small diameter portion which assumes a linear shape in an axial direction, and a center electrode has an outer diameter increasing in the order of a frontmost portion, a step portion, a front end portion and a body portion.

Abstract: A spark plug includes an insulator having a first end, the insulator having a center axis and a center electrode coupled to the insulator and having a center electrode tip extending beyond the first end of the insulator. The spark plug further includes a ground electrode having an end spaced from an end of the center electrode, the ground electrode having a first portion extending substantially parallel to the center axis and a second portion extending at an angle from the first portion and relative to the center axis. A ground electrode tip is disposed on the second portion of the ground electrode, wherein the ground electrode tip is spaced from the center electrode tip. A ring member is operatively connected to the center electrode proximate the center electrode tip.

Abstract: An ignition device having an electrode structure including an anode, a cathode, an auxiliary electrode, an anode coating, an auxiliary electrode coating, and an anode supporting body. A coated surface of the anode is opposed to a coated surface of the auxiliary electrode with the anode coating, a combustion space, and the auxiliary electrode coating therebetween. An exposed surface of the anode is opposed to an exposed surface of the cathode with the combustion space therebetween. A distance D1 from the coated surface of the anode to the coated surface of the auxiliary electrode via the anode coating, the combustion space, and the auxiliary electrode coating is shorter than a distance D2 from the exposed surface of the anode to the exposed surface of the cathode via the combustion space (D1<D2). A combustion bomb may be used as the cathode.

Abstract: A plasma jet ignition plug that reliably prevents current leakage with restraint on variation in the position of a ground electrode relative to an insulator and on overheat of the ground electrode, for stable generation of plasma. The plug includes an insulator having an axial bore extending in the direction of an axis CL1, a center electrode inserted in the axial bore, a metallic shell disposed externally of the outer circumference of the insulator, and a ground electrode fixed to the metallic shell, and has a cavity defined by the wall surface of the axial bore and the front end surface of the center electrode. Supports intervene between the insulator and the ground electrode. A space formed radially outward of the supports and a space formed radially inward of the support communicate with each other.

Abstract: A plasma jet ignition plug having high ignition performance and high durability. The plasma jet ignition plug comprises a center electrode wherein at least a front end portion including a front end surface of the center electrode contains an oxide of at least one of the rare earth elements in a total amount of 0.5% by mass to 10% by mass inclusive and tungsten (W) in an amount of 90% by mass or greater, or contains iridium (Ir) in an amount of 0.3% by mass to 3% by mass inclusive and W in an amount of 97% by mass or greater.

Abstract: A spark plug, especially for a stationary internal combustion engine, is described that includes a ground electrode and a center electrode, the center electrode including an inner area, an outer ring and at least two crosspieces, in which the at least two crosspieces connect the inner area to the outer ring.

Abstract: A plasma jet spark plug comprising: a center electrode; an insulator having an axial bore extending in an axial direction, and retaining the center electrode within the axial bore; a metallic shell surrounding and retaining the insulator from outside with respect to a radial direction perpendicular to the axial direction; and a ground electrode disposed frontward of the front end portion of the insulator with respect to the axial direction, wherein the ground electrode has a contact portion contacting the front end portion of the insulator in an annular contact zone, the ground electrode is not in contact with the metallic shell with respect to the axial direction and the ground electrode is in contact with the metallic shell with respect to a radial direction perpendicular to the axial direction and is electrically connected with the metallic shell by means of an outer peripheral portion thereof being joined to the metallic shell.

Abstract: An ignition system includes an electrical energy delivery device having a first electrode terminating at a first end portion and a second electrode positioned in the ignition system separately from the electrical energy delivery device. The second electrode terminates at a second end portion disposed a first distance from the first end portion to form an air gap therebetween. The air gap forms an area including the shortest distance between the first electrode and the second electrode.

Abstract: The invention is a spark plug having multiple precise spark gaps (G} with a donut shaped electrode (20) attached to the firing end of the central electrode (32), as well as a cylindrical ground sleeve (40) that is pressed on to the primary shell (36) of the spark plug. The electrode donut (20) is generally flat and laded out in a radial direction towards the ground prongs (42) that protrude up towards the firing end from the ground sleeve (40). In conjunction with their structure, allow for the generation of a spark from every single ground prong (42) on the ground sleeve (40). This is spark potential area (G). Such multiple spark potential area along with the electrode donut (20) and ground sleeve (40) relation provides a more rapid and complete combustion of the air-fuel mixture within the internal combustion engine, which, in turn, results in more torque and more horse power.

Abstract: A combined igniter and flame sense electrode for a dual stage gas burner that includes a first burner and a second burner is disclosed. The electrode includes a first conductive element mounted on the shaft and positioned closer to the first burner than to the second burner; a second conductive element mounted on the shaft and positioned closer to the second burner than to the first burner; and one or more electrical connectors connected to the conductive elements. An electrode according to the invention can also be used with a single stage gas burner, by placing the first conductive element at the position of high level flame from the burner and by placing the second conductive element at the position of low level flame from the burner. A gas burner assembly incorporating such an electrode, and a gas appliance incorporating such a gas burner assembly, are also disclosed.

Abstract: An ignition plug having a center electrode, an insulator holding the center electrode in an axial bore, and a ground electrode disposed in contact with a front end portion of the insulator and having a through-hole whose center coincides with the axis of the center electrode. A semiconductor layer in contact with the center electrode and the ground electrode is formed in a portion of the surface of the insulator.

Abstract: A spark plug includes a ceramic insulator sleeved on a center electrode so that an end of the center electrode extends outwardly of an end surface of the ceramic insulator, a conductive outer shell surrounding spacedly the ceramic insulator, and a ground electrode including an annular portion disposed coaxially around the end of the center electrode such that an annular gap smaller than 1 mm is defined between the annular portion and the ceramic insulator, and a connecting portion interconnecting electrically the annular portion and the conductive shell. The annular portion of the ground electrode cooperates with the end of the center electrode and the end surface of the ceramic insulator to define an air-blocking space thereamong in spatial communication with the annular gap.

Abstract: A spark plug assembly (22) includes a center electrode (34) having a high performance metal sleeve (50) attached at its sparking end. The sleeve (50) is fitted to a tenon on the end of the center electrode (34) and fixed in place by a weld line (58) produced by laser beam pulses (56). The weld line (58) is applied by overlapping a plurality of spaced-apart beads in a single, continuous circumscribing line. The sleeve (50) is permitted to expand and contract under the influence of thermal cycling without constraint except for the fixation weld line (58). Therefore, the sleeve (50) does not experience stress build-ups resulting from differing rates of thermal expansion relative to the center electrode (34), which is preferably made from a nickel or other composition dissimilar to that of the high performance metal sleeve (50). Various ground electrode (30, 60) configurations are possible.

Abstract: The invention is a spark plug having multiple precise spark gaps (G} with a donut shaped electrode (20) attached to the firing end of the central electrode (32), as well as a cylindrical ground sleeve (40) that is pressed on to the primary shell (36) of the spark plug. The electrode donut (20) is generally flat and laded out in a radial direction towards the ground prongs (42) that protrude up towards the firing end from the ground sleeve (40). In conjunction with their structure, allow for the generation of a spark from every single ground prong (42) on the ground sleeve (40). This is spark potential area (G). Such multiple spark potential area along with the electrode donut (20) and ground sleeve (40) relation provides a more rapid and complete combustion of the air-fuel mixture within the internal combustion engine, which, in turn, results in more torque and more horse power.

Abstract: A spark plug is provided, for a provisional bending process for manufacturing the spark plug, as a work in a condition where an earth electrode is straight and substantially in parallel with an axial line of a center electrode. In the provisional bending process, two searchers individually facing the tip of the center electrode with the tip located therebetween are arranged, positions of the searchers in a first direction perpendicular to the axial line being adjusted for every spark plug. Then a bending punch is driven to press a second end-surface of the other end of the earth electrode down to the searchers so that the earth electrode is provisionally bent at a substantially perpendicular angle to the axial line, the second end-surface being opposite to the first end-surface. Preferably, before the provisional bending process, positioning the work and correcting the position and tilt of the work are performed.

Abstract: In a first embodiment a spark plug satisfying the relations: t?0.3 mm and St/Sw?7 in which t is the axial-direction shortest distance between a leading end surface 41a of a precious metal tip 41 and a joint portion 43, St is the surface area of the precious metal tip 41 and a joint portion 43 between the precious metal tip 41 and the ground electrode body 4a, and Sw is the area of the joint portion 43 between the ground electrode body 4a and the precious metal tip 41. In a second embodiment, the spark plug satisfies the relations t?0.3 mm and La>Lb; and in a third embodiment the spark plug satisfies the relations t>T and La>Lb, where T, La and Lb are as defined in the specification. The relation t?0.3 mm is specific to the first and second embodiments, and the relation St/Sw?7 is specific to the first embodiment only.

Abstract: A spark plug and fuel injector combination. The spark plug has a central channel that funnels fuel into the lower portion of the spark plug, where it is superheated. A solenoid system causes a needle valve to rise up to allow a measured quantity of fuel to be injected into a cylinder through a nozzle, where it vaporizes upon exiting the spark plug. A spring releases the needle valve to close the nozzle. The spark plug also has an ignition ring on the base. The ignition ring produces an encompassing spark, which produces complete combustion of the vaporized fuel. This produces more power and better fuel economy.

Abstract: A spark plug includes a sparking electrode with a firing tip and a ground electrode. The ground electrode includes a toroidal member, having a convex outer surface, coupled to a support portion of a sleeve of the ground electrode. The toroidal member forms an annular curve disposed generally transverse to and having a radial center coinciding with a central axis of the insulator body, whereby each differential segment of the toroidal member radially thereabout is generally equidistant to the firing tip. The toroidal member is a closest portion of the ground electrode relative to the firing tip. At least a portion of the outer surface of the toroidal member opposing the firing tip has a radius of curvature of about that of the firing tip for providing a spark path of least from the firing tip to a point of contact on the opposing surface defined by the toroidal member.

Abstract: An ignition device for internal combustion engine including a spark plug containing a housing, an insulator having a central electrode and a sidewall electrode attached to the housing and forming a spark gap between the sidewall electrode and the end of the center electrode, where the space around the spark gap is covered with the internal conic surface of the housing expanding outwards, and a capacitive electric energy storage device attached to the spark plug, whereas the housing of the spark plug includes an attachment and a base part, whereas the attachment includes an internal conic surface expanding outwards and a slot for sidewall electrode.

Abstract: A spark plug is described that includes a housing, an insulator nose attached to the housing, a center electrode inserted through the insulator nose and projecting over the insulator nose tip, an intermediate electrode separated from the center electrode by a first spark gap, and a ground electrode attached to the housing. A solid-state insulating body, which forms a second spark gap in the form of a surface gap passing over the solid-state insulating body, is provided between the intermediate electrode and the ground electrode.

Abstract: An ignition spark plug which comprises an insulator containing a center bore, a center electrode extending through the center bore in an insulator; a circular plate-type center electrode attached to and extending from one end of said center electrode, said circular plate-type center electrode including: a plurality of grooves provided at the periphery of the circulate plate-type electrode defining a tooth wheel for expanding the size of the spark in an ignition chamber; and a ring electrode disposed at an end of a threaded metal shell extending from a metal housing and spaced apart from said circular plate-type center electrode, whereby the improved ignition spark plug provides an excellent starting ability of the engine, completes the combustion of the fuel in the ignition chamber, and prevents the exhaust gas from fuming out.

Abstract: A spark plug derives an extended lifetime because a large plurality of sharp edges are provided on the center electrode, the ground electrode, or both to enhance spark propagation. In a first embodiment, the ground electrode has a conventional cantilever shape, but the center electrode extends into coplanar relation to a distal surface of the electrode so that sparks propagate from the cylindrical side walls of the center electrode. In variations of the first embodiment, the number of cantilevered ground electrodes is increased, with the ground electrodes being circumferentially and equidistantly spaced about the center electrode. In another embodiment, the ground electrode has an annular configuration and includes a cylindrical annular wall spaced radially outwardly of the cylindrical sidewall of the center electrode, in concentric relation to the center electrode.

Abstract: A high efficiency spark plug includes a ground electrode having formed of a wire having a circular cross section. The ground electrode has a pair of stanchions and a loop extending over the center electrode of the spark plug. The loop has a center circular portion and a pair of curved portions which form a gap between the two sides of the loop generally equal to the diameter of the wire.

Abstract: A spark plug derives an extended lifetime because a large plurality of sharp edges are provided on the center electrode, the ground electrode, or both to enhance spark propagation. In a first embodiment, the ground electrode has a conventional cantilever shape, but the center electrode extends into coplanar relation to a distal surface of the electrode so that sparks propagate from the cylindrical side walls of the center electrode. In variations of the first embodiment, the number of cantilevered ground electrodes is increased, with the ground electrodes being circumferentially and equidistantly spaced about the center electrode. In another embodiment, the ground electrode has an annular configuration and includes a cylindrical annular wall spaced radially outwardly of the cylindrical sidewall of the center electrode, in concentric relation to the center electrode.

Abstract: A spark plug, especially one for a gas-fueled internal combustion engine has an electrically conducting spark plug body (1), a central electrode (3) which is located in the spark plug body (1) and which is electrically insulated from and projects away from the spark plug body (1), and a ground electrode (4) which is electrically connected to the spark plug body (1) and is made in the form of an annular electrode. The annular electrode (4) surrounds the front part of central electrode (3) such that an annular ignition gap (ZS) is formed between them. Surfaces of the central electrode (3) and the annular electrode (4) bordering the ignition gap (ZS) are provided with precious metal armorings in the form of sleeves (5, 6,), especially of platinum or a platinum alloy. This yields a spark plug with an extremely long service life.

Abstract: A self-grounding igniter for an industrial burner that is more durable and less fragile, by virtue of the insulating jacket being relatively short and limited to the tip end of the igniter. The burner has a final inlet, an air inlet, a housing and a burner nozzle inside the housing. The igniter comprises a metal rod having a discharge electrode at one end and a mount and connector at the other end. The connector is adapted to be electrically coupled to a power source. An insulating jacket circumscribes a top end segment of the metal rod in proximity to the discharge electrode. A ground electrode metal sleeve is mounted to the outside of the insulating jacket in fixed proximity to the discharge electrode, thereby forming a spark gap having a fixed distance. This configuration provides an exposed metal surface on the rod between the insulating jacket and the mount. The exposed metal surface has a length substantially corresponding to the distance between the housing and the burner nozzle.

Abstract: A spark plug including a ground electrode having an arcuate arm portion coupled with an annular upper end portion of the outer portion of a spark plug. The ground electrode has a concave portion secured to a distal end of the arcuate arm portion with the concave portion disposed over an open end portion of a central electrode within the spark plug. The concave portion has an aperture formed therethrough.

Abstract: A sparking device, in one aspect, includes first and second electrodes for coupling with corresponding first and second electric potentials. The first electrode includes an elongate member having proximal and distal parts. The second electrode includes a body receiving the proximal part. A first insulation portion electrically insulates the proximal part of the elongate member from the body. The first electrode includes an end member connected with the distal part of the elongate member. The end member includes a first section with a plurality of first electrical contacts offset from a longitudinal axis of the device. The body includes a second section with a plurality of second electrical contacts offset from the longitudinal axis.

Abstract: A high efficiency spark plug includes a ground electrode having formed of a wire having a circular cross section. The ground electrode has a pair of stanchions and a loop extending over the center electrode of the spark plug. The loop has a center circular portion and a pair of curved portions which form a gap between the two sides of the loop generally equal to the diameter of the wire.

Abstract: An internal combustion engine that burns fuel from a fuel source, and an engine including a block assembly with a piston cylinder, a combustion chamber connected to the piston cylinder, and an air/fuel mixing area that communicates with the combustion chamber for delivering an air/fuel mixture to the combustion chamber. A fuel delivery system is connected to the block assembly, and the fuel delivery system is adapted to deliver a selected amount of fuel into the mixing area for mixing with air therein to provide an air/fuel mixture having an air-to-fuel ratio in the range of approximately 20:1 to 45:1, inclusive. A spark plug is connected to the block assembly and positioned to generate a spark in the combustion chamber to detonate the air/fuel mixture. The spark plug has a center electrode and a ground electrode axially spaced apart from each other by a spark gap in the range of approximately 1.8 mm to 3.0 mm.

Abstract: A spark plug includes a ground electrode and a center electrode. The ground electrode comprises a ring shaped member which is centered on the center electrode. A beveled ring shaped surface of the ring shaped member generally faces the center electrode. This increases the spark area of the ground electrode, providing for more consistent and stronger sparks, and even multiple sparks. A cross shaped channel is disposed centrally on a distal face of the center electrode. Because of the increased spark area which the channel provides, the spark is more likely to travel along the channel, rather than jump from point to point along the distal face of the center electrode, as can happen with conventional spark plugs; thus, the channel provides a stronger and more consistent spark.

Abstract: In a spark plug in use for an internal combustion engine, a ground electrode is secured to a front end of the metal shell so that a front end surface of the ground electrode faces an elevational side of a front end of the center electrode to cause semi-creeping spark discharges therebetween along a front end surface of the insulator. A front end portion of the center electrode has an electrode base in the axial bore and an electrode front defined diametrically smaller than the electrode base by way of a diameter-variable portion. A diametrical difference between an initial point of the diameter-variable portion of the center electrode and the axial bore of the insulator is 1 mm or less, and the initial point of the diameter-variable portion is retracted by 0.0 mm-1.0 mm from the front end surface of the insulator.

Abstract: A spark plug derives an extended lifetime because a large plurality of sharp edges are provided on the center electrode, the ground electrode, or both to enhance spark propagation. In a first embodiment, the ground electrode has a conventional cantilever shape, but the center electrode extends into coplanar relation to a distal surface of the electrode so that sparks propagate from the cylindrical side walls of the center electrode. In variations of the first embodiment, the number of cantilevered ground electrodes is increased, with the ground electrodes being circumferentially and equidistantly spaced about the center electrode. In another embodiment, the ground electrode has an annular configuration and includes a cylindrical annular wall spaced radially outwardly of the cylindrical sidewall of the center electrode, in concentric relation to the center electrode.

Abstract: A spark plug having the electrodes composed of twisted stainless steel wire with their spark gap ends frayed so as to give more spark contacting area, reduce heat and eliminate wear on the electrodes, thus giving a stronger, more efficient spark and more efficient combustion of the fuel-air mixture in the cylinders. A sealing means is also incorporated in the interior of the plug to prevent escape of any combustion products. The frayed ends will vibrate during the firing cycle, which will shake off any carbon which may tend to accumulate on them. A modification shows the ends of the wires not frayed but solid and clean cut.

Abstract: A spark plug has a central electrode and a plurality of peripheral electrodes. The central electrode has a proximal portion and a distal portion. The distal portion of the central electrode has a circular cross-section with a longitudinal axis and terminates in a distal end. Each peripheral electrode has a lower portion and an upper portion. Each upper portion has a distal-most point. Each distal-most point is disposed in a central plane within which the longitudinal axis of the distal portion of the central electrode is wholly disposed. The cross-section of each upper portion taken along its central plane defines a convex outer side and a non-convex inner side. Each convex outer side has a curved surface which is tangent to a plurality of tangent planes, all of which intersect the longitudinal axis of the distal portion of the central electrode at points at or above the distal end of the distal point of the central electrode.