Ceramic electrode, ignition device therewith and methods of construction thereof
AssigneeFederal-Mogul Ignition Company
InventorsWilliam J. Walker, Jr., James D. Lykowski
Life of this patent
Estimating the term…
Abstract
A spark plug, a center electrode therefore and method of construction is provided. The spark plug has a generally annular ceramic insulator extending between a terminal end and a nose end. A conductive shell surrounds at least a portion of the ceramic insulator and a ground electrode having a ground electrode sparking surface is operatively attached to the shell. An elongate center electrode has a body extending between opposite ends, wherein the body is compacted and sintered of a conductive or semi-conductive ceramic material. One of the electrode ends provides a center electrode sparking surface to provide a spark gap between the center electrode sparking surface and the ground electrode sparking surface.
Claims16
A spark plug comprising:
- a ceramic insulator extending along a longitudinal axis and presenting a central passage between a teiminal end and a nose end with a transition shoulder between said ends;
- a glass seal being conductive and disposed in said central passage;
- a center electrode disposed in said central passage of said insulator and including a head abutting said transition shoulder and encased in said glass seal;
- said center electrode including an elongate body extending longitudinally from said head;
- said elongate body being constructed of a ceramic material and sintered to said insulator;
- and
- said ceramic material including borides having a chemical composition of the formula MxBy, where M is a metallic element, X is 1, and Y is 1, 2 or 6.
A spark plug, comprising:
- a generally annular ceramic insulator extending along a longitudinal axis and presenting a central passage between a terminal end and a nose end with a transition shoulder between said ends;
- a glass seal being conductive and disposed in said central passage;
- a conductive shell surrounding at least a portion of said ceramic insulator;
- a ground electrode operatively attached to said shell, said ground electrode having a ground electrode sparking surface;
- a center electrode disposed in said central passage of said insulator and including a head abutting said transition shoulder and encased in said glass seal,
- said center electrode having an elongate body extending along a longitudinal axis from said head to an opposite end,
- said end having a center electrode sparking surface,
- said center electrode sparking surface and said ground electrode sparking surface providing a spark gap,
- said elongate body being constructed of a ceramic material and sintered to said insulator, and
- said ceramic material including borides having a chemical composition of the formula MxBy, where M is a metallic element, X is 1, and Y is 1, 2 or 6.
A method of constructing a spark plug, comprising:
- compacting a ceramic material to form a generally annular ceramic insulator having a central passage extending between a terminal end and a nose end and having a transition shoulder between the ends;
- forming a conductive shell configured to surround at least a portion of the ceramic insulator;
- forming a ground electrode;
- operatively attaching the ground electrode to the shell;
- compacting a ceramic material including borides having a chemical composition of the formula MxBy, where M is a metallic element, X is 1, and Y is 1, 2 or 6 to form an elongate center electrode having a head and an elongate body extending from the head;
- abutting the head of the elongated body to the transition shoulder of the insulator;
- sintering the compacted ceramic materials of the insulator and the elongated body of the center electrode together;
- disposing the sintered insulator and the center electrode in the shell;
- and
- disposing a conductive glass seal in the central passage of the insulator so that the head of the electrode is encased in the glass seal.
Dependencies are inferred from the claim text.