Patent ID: 7148612
Filing Date: 2006-12-12
Classification: H01T

Abstract:
1. A spark plug comprising an electrically-insulating sleeve extending along a central axis of the plug, a first electrode mounted within the sleeve and having a tip projecting beyond said sleeve, an electrically-conducting shell surrounding said sleeve, and a second electrode mounted on and electrically-connected to said shell, the second electrode having a tip positioned in opposed-relationship to the tip of said first electrode, the tips of said first and second electrodes each having a spark surface facing the spark surface of the other electrode, the spark surfaces of the two electrodes defining a spark gap of the plug, characterized in that the spark surfaces of the first and the second electrodes are inclined at different angles relative to a plane extending normally of said central axis of the plug so that said spark gap varies in width along the length of the gap with the narrowest point of the gap being further from the connection between the second electrode and the shell than the other end of the gap, wherein the spark surface of the first electrode is inclined at an angle between 20 degrees and 55 degrees to a plane extending normally of the central axis of the plug.