High energy ignition device

Claim 1

In a gas turbine engine having a combustion chamber and a fuel supply and means for delivering a fuel-air mixture to the combustion chamber, an igniting device wherein the improvement comprises: a. a head member mounted on the combustion chamber and having a fuel connection to receive fuel from the fuel supply and bearing a tubular well extending into the combustion chamber, the well having an apertured inner end wall; B. a tubular insulator positioned within the well and having an electrode disposed therein, the insulator defining a spark path between the electrode and the inner end of the well; c. the tubular insulator having a smaller outer diameter than the inner diameter of the well and defining an annular channel therewith, the head member having passage means communicating between the fuel connection and the annular channel, and the inner end of the insulator having passage means therein communicating between the annular channel and the spark path to deliver fuel thereto; d. the inner end face of the insulator being seated against the apertured inner end wall of the well, the inner diameter of the insulator at its inner end being funnel shaped with the larger diameter of the funnel adjacent to the end wall of the well, the aperture in the end wall of the well being approximately the same diameter as the large end of the funnel; and e. an electrical power supply connected to the electrode to initiate an arc across the spark path to vaporize and ignite the fuel in the spark path, the ignited fuel being propelled as a flame into the main fuel-air mixture.