Technique and spark plug to ignite very lean fuel air mixtures, particulary for gas engines

A spark plug construction for use in an opening of a combustion cylinder defining a main combustion chamber comprising:

• a connecting electrode;
• an insulating body surrounding said connecting electrode;
• a housing connected to said insulating body and surrounding said insulating body;
• an ignition chamber housing connected to said housing defining an ignition chamber, said connecting electrode having an end extending into said ignition chamber, said ignition chamber housing defining transfer channels providing fluid communication between the main combustion chamber and said ignition chamber;
• an ignition electrode connected to said connecting electrode, said ignition electrode being positioned in said ignition chamber;
• a counter electrode connected to said ignition chamber housing, said counter electrode cooperating with said ignition electrode to form a spark gap between said ignition electrode and said counter electrode;
• admixture line means defined by said housing for providing an admixture from outside the cylinder to one of a space in said main combustion chamber adjacent one of said transfer channels and directly to one of said transfer channels intermediate said ignition chamber and the main combustion chamber, said admixture line means having at least one valve, said valve includes control means for opening and closing said valve in response to the pressure of the admixture in said admixture line means and in response to the pressure in said main combustion chamber, said valve is positioned at an outlet of said admixture line means adjacent said combustion chamber.