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:
Nov. 08, 1994
Filed:
Apr. 05, 1993
Koji Hatanaka, Saitama, JP;
Takashi Aota, Saitama, JP;
Jidosha Kiki Co., Ltd., Tokyo, JP;
Abstract
In a glow plug, a resistance element buried in an elongated, rod-like insulating ceramic member includes first and second resistive heating elements. The first heating element is arranged at the front end portion of a ceramic heater and made of a positive temperature coefficient resistive ceramic material, containing silicon nitride, such as SiAlON. The second heating element is arranged behind of and connected in series with the first heating element and made of a metal material (e.g., tungsten) having a positive temperature coefficient of resistance larger than that of the first heating element. Both heating elements are arranged in the portion of the ceramic member projecting outwardly from the holder and metal pipe fitted about the control portions of the ceramic member. The glow plug further comprises a metal holder holding the rod-like member in a way that a front portion of the rod-like member protrudes from the metal holder. The metal holder is substantially tubular and includes a metal pipe fitted on and fixed at a central portion in a longitudinal direction of the rod-like member, and is connected to the second heating element.