Spark discharge perforator for moving foil - using needle electrodes inside spring-loaded insulating sleeves with hemispherical foot

摘要

Moving foil is perforated by passing the foil on a counter electrode and applying to it a row of needle-shaped electrodes so that electrical spark discharges can be produced. Each of the electrodes is fitted in its own sleeve made of an insulating material, pref. with a high abrasion resistance such as PTFE, glass or porcelain. The sleeve rests, loaded by a spring, on the foil through a hemispherical foot. A high-tension generator applies pulses between electrodes and counter electrode. Electrodes can thus be kept to a small dia. without risk of scratching or damaging the foil surface. Uniform holes are punctured by this device.