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.

Abstract: To provide for better distributor radio interference noise suppression and to localize resistance elements used in connection therewith as close to the spark gap of the distributor, the rotor electrode and/or the stationary electrodes in the distributor are made of a resistance material which has a sufficiently high resistance to provide for effective interference suppression; the material may be a high-melting oxynitride, particularly of a metal of the III or IV-B to VI-B groups of the periodic table; or a ceramic substrate, on which a coating is applied, for example of high melting point titanium, zirconium or aluminum oxide which are rendered conductive by being present in less than stoichiometric proportions; or silicon compounds such as chromium-silicon compounds, molybdenum-silicon compounds, with or without a matrix of silicon or ceramic-metal mixture in which the metal is both a binder and a conductive component, particularly Al.sub.2 O.sub.3 -Mo, Cr.sub.2 O.sub.3 -Si, SiC-Cr-Ni and B.sub.4 C.sub.

Abstract: Powdered binder metal and hard metal granules are deposited in measured quantities on the cutting edge of a metal blade. When these materials both have a magnetic component, an electromagnet with an elongated air gap is used to pick up quantities determined by the amount of exciting current and to deposit them on the surface to be coated. A high-frequency heating current flows through the object being coated and also through a nearby inductor in series. This produces a short heating cycle in which the binder metal is melted, this being done in a protective gas atmosphere and without the presence of a flux. The object to be coated is held in a clamping device provided with a cavity around the surfaces to be coated, which include adjacent side surfaces as well as the edge of the blade, and the clamping plates also operate as heat sinks. The method and apparatus can also be used for sintering on a coating, but that requires a longer heating cycle.