Image Number 2 for United States Patent #4509469.
A break ignition plug for piston engines wherein an electromagnet acts upon an armature which activates a movable electrode and an ignition pulse passes through the magnet coil of the electromagnet and a short-circuit path between the electrodes. The magnetic field which builds-up in the electromagnet causes breaking of the short-circuit path and spark formation. At the free end of blade or band springs arranged in spaced relationship from one another at the lengthwise axis of the ignition plug there are provided confronting electrode heads. The blade springs are retained at the magnet core and freely protrude by means of the electrode ends into a hollow space or chamber formed at a threaded portion of the ignition plug. At a magnet gap region of the core there are formed at the blade springs armatures which repel one another upon excitation of the electromagnet.