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 spark plug for internal combustion engines comprises a center electrode enclosed in an insulating body enclosed in a metal housing, and a ground electrode. The insulating body has an end portion which faces the combustion chamber. An electrical field develops, resulting in a surface spark gap between two electrodes on the surface of the insulating body at the end portion thereof. The insulating body is transversely divided into the upper portion and the lower portion, of which the lower portion facing the combustion chamber is made of a material having dielectric constant 5-50 times higher than that of the upper portion.

Abstract: An ignition plug suitable for igniting meager fuel vapor/air mixtures has a tubular metal housing, an insulating body which is divided into longitudinal portions and contains a connection pin and a middle electrode positioned in its through borehole. A longitudinal portion of the insulating body, which longitudinal portion is enclosed by the metal housing, consists of dielectric material and, together with the metal housing and the connection pin, forms a capacitor which has a capacity of 120 to 500 pF, chiefly 200 to 400 pF. In order to connect electrial flashovers between the connection pin and the metal housing in the areas of the separating surfaces of the insulating body annular electrical insulating elements are arranged between the separating surfaces which are made of the material elastic at all temperatures of the ignition plug.

Abstract: To improve the noise suppression characteristics of an ignition system for an Otto-type internal combustion engine, radio noise suppression resistors (8, 18, 22) are molded into the distributor cap (25) and electrically connected, respectively, between the tower cable connectors (19, 21, 23) on the distributor cap and the respective distributor cap terminals, which may be the peripheral terminals (16, 17) or the center wiping or sliding terminal (9) for the distributor rotor. The distributor rotor then can have a single highly conductive electrical element as a center electrode, leading to the outside peripheral rotating distributor electrode (14), which is spaced from the fixed gap electrodes by a spacing of between 0.5 to 3 mm, preferably at least 2 mm. Preferred values for the noise suppression resistors are between 1 to 5 kilo ohms.

Abstract: In order to make possible the lower level of electrostatic disturbance that accompanies the use of a wider than usual gap in an ignition distributor without undesirable increase of the ignition pulse voltage, the distributor electrode and/or the fixed ignition circuit electrodes of the distributor are made at least in part of a material that requires less energy for pulling out an electron and has a higher secondary electron emission capability than the usual brass plate used for the contact plate at the axis of revolution of the distributor rotor, to which a carbon brush is usually provided for making contact. Alloy additions of calcium oxide or barium oxide or silicon to brass have a suitable effect and an alloy containing silicon and preferably also aluminum and calcium is preferred. The gap width is between 3 and 5 mm, preferably about 4 mm for normal motor vehicle engine application.

Abstract: The part of the distributor electrode in the breakdown region has a resistance of at least 400 ohms per millimeter. The total resistance of the electrode is in the range of between 0.5 and 1.0 kilo-ohms. The material is a mixture of a resistive ceramic material and a finely dispersed additive of metallic conductivity. Arrangements for creating surface discharge gaps thereby slowing down the sparking process and decreasing interference are also illustrated.