Engine ignition system with electromagnet control of enclosed distributor gaps

Claim 1

An ignition system for an internal combustion engine, said ignition system having a plurality of high-voltage switches contained in hollow gas-filled envelopes of insulating material for switching spark plugs, said switches comprising in each gas-filled envelope a cathode electrode and an anode electrode projecting into the interior of said envelope and means adjacently outside the envelope including a nearby movable control electrode at a predetermined potential for promoting the allocation of a high-voltage pulse to the cathode and anode of the neighboring envelope in one but not all of the positions to which said electrode is movable, each said cathode having in the respective envelope a lateral extension reaching at least approximately to the wall of said envelope, said control electrode being arranged to be movable outside said envelope so as to move past a position at least partly consituting a further extension of said lateral extension of said cathode in order to promote a discharge of said high-voltage pulse in said envelope, said system having the improvement which consists in that: at least one electromagnet is provided for controlling said movable electrodes, and said at least one electromagnet, when selectively energized, moves at least one respective control electrode (39, 53) alongside the lateral extension (38,52) of the cathode of a corresponding high-voltage switch (33,34).