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. 29, 1976
Filed:
Oct. 22, 1974
Osami Kamigaito, Nagoya, JA;
Haruo Doi, Nagoya, JA;
Hideyuki Masaki, Nagoya, JA;
Toshio Kandori, Nagoya, JA;
Masami Oki, Nagoya, JA;
Yasuo Nakamura, Nagoya, JA;
Nippondenso Co., Ltd., BOTH OF, JA;
Kabushiki Kaisha Toyota Chuo Kenkyusho, BOTH OF, JA;
Abstract
A resistor built-in spark plug comprises an insulator formed with an axially extending inner hole, a stem fitted in the upper part of said hole in said insulator, a center electrode fitted in the lower part of said hole, a resistor disposed in the central part of said hole, and copper-glass electrode layers disposed between said resistor and said stem and between said resistor and said center electrode. Said resistor is made by firing and solidifying powder of resistor mixture consisting of 75 to 38 volume percent of main resistor component containing tin oxide and 25 to 62 volume percent of glass powder with softening temperature of 300.degree. to 600.degree.C. Said copper-glass electrode layers are made by firing and solidifying a mixture of copper powder and glass powder with the softening temperature of above 530.degree.C and more than 30.degree.C higher than the softening point of glass in the resistor portion.