The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 06, 2000
Filed:
Mar. 08, 1999
Chin-Fong Chang, Morris Plains, NJ (US);
Richard Dale Taylor, Findlay, OH (US);
Lee Randall Franz, Findlay, OH (US);
Edgar Arnold Leone, Randolph, NJ (US);
Alex Kozlov, Wharton, NJ (US);
AlliedSignal Inc., Morristown, NJ (US);
Abstract
A wear-resistant electrode tip for a spark plug, and a spark plug which incorporates the wear-resistant tip. The wear-resistant tip includes an alloy of platinum, iridium, and tungsten. Surprisingly, by addition of a small amount of tungsten to platinum-iridium alloy, the wear-resistance of a resultant spark plug is greatly improved. The spark plug electrode tip according to the invention is either spherical or rivet-shaped. During manufacture, the spark plug electrode tip is annealed in an annealing furnace. The annealing furnace is preferably either charged with an inert gas such as argon or nitrogen, or is subjected to a vacuum. The electrode tip is, optionally, further externally coated with platinum or a compatible bonding metal alloy before attachment to the electrode. Subsequent to annealing and, where used, to external coating, the spark plug electrode tip is placed in a welding fixture. The tip is then aligned with a spark plug electrode and is resistance welded thereto. Similar procedures are preferably performed on both the center and side electrodes of the spark plug. The annealed spark plug electrode tips using the novel alloys according to the invention have a high resistance to attack by lead and other corrosive elements typically present in the combustion chambers of internal combustion engines. A preferred method of making a wear-resistant spark plug is also disclosed.