Break ignition plug

Claim 1

A break ignition plug for piston motors or the like having a cylinder with an internal compartment comprising: an electromagnet including a magnet coil; an armature acted upon by said electromagnet; a movable electrode actuated by said armature; a counterelectrode cooperating with said movable electrode and defining therebetween a short-circuit path, said counterelectrode defining a ground electrode; an ignition pulse flowing through the magnet coil of the electromagnet and the short-circuit path between the movable electrode and the counterelectrode; the magnetic field which builds-up in the electromagnet causing breaking of the short-circuit path with spark formation; means defining a pressure equalization chamber capable of communicating with an internal compartment of the cylinder of the piston motor for relieving the forces which are to be applied by the armature for the movement of the movable electrode; a spring provided for the electromagnet against which there can be attracted the armature; said armature being dispositioned at least in part at a side of the electromagnet intended to confront the inner compartment of the cylinder of the piston motor; said armature supporting the movable electrode which extends in the direction of the inner compartment of the cylinder; said movable electrode having a contact tip; an ignition plug housing receiving therein the electromagnet and armature; a bottom portion provided for the ignition plug housing and having means for opening thereof into the inner compartment of the cylinder; said contact tip of the movable electrode protruding into the bottom portion of the ignition plug housing; and said counterelectrode being fixedly mounted at the ignition plug housing and being arranged in the axial direction with respect to the movable electrode which is movable vertically towards and away therefrom.