Spark plug shell having a bimetallic ground electrode spark plug incorporating the shell, and method of making same
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Dec 4, 2001
Grant Date -
N/A
app pub date -
Jun 16, 1999
filing date -
Jun 16, 1999
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
A spark plug includes a metal shell, an insulator coaxially disposed within the metal shell, and a center electrode coaxially disposed in the insulator. The metal shell has a substantially cylindrical base portion, and the base portion has a lower surface with a recess formed therein. A bimetallic ground electrode is affixed to the lower surface of the base portion at the recess thereof The ground electrode has a central core formed of a first thermally conductive metal which may include copper, and an external sheath surrounding the core, the sheath being made of a second metal which includes nickel. The recess in the lower surface of the metal shell is preferred to be provided as an annular grove extending therearound. The present invention also encompasses a method of making a spark plug, including a step of placing a ground electrode adjacent a lower surface of a spark plug shell, aligned with a recess thereof, such that a tip end of the ground electrode enters into the recess. Another step in the method involves welding the ground electrode to the spark plug shell.
First Claim
Other Claims data not available