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:
Mar. 21, 2000
Filed:
Oct. 06, 1998
Hideki Kita, Kanagawa-ken, JP;
Hideo Kawamura, Kanagawa-ken, JP;
Isuzu Ceramics Research Institute Co., Ltd., Kanagawa-ken, JP;
Abstract
The present invention provides a unit sheath adaptable to a glow plug or a thermocouple, which is improved in durability by the protection from burn-out of the conductive filament. The unit sheath is preferably adapted to a glow plug 10. A protective envelope 1 of ceramics high in density includes a metallic filament 4 of any one of pure tungsten, molybdenum or alloy thereof. A high-density sealant 3 hermetically closes the envelope 1 at its opened end 5. Filler 2 of non-conductive, unburned material is packed in the space around the metallic filament 4 in the envelope 1. The filler contains therein an additive 7 that may be subjected to the oxidation at the temperature lower than that of the metallic filament 4. The additive 7 is composed of at least any one of a free oxygen absorber selected from the group of carbon, titanium, boron, aluminum and nitride thereof, or the mixture thereof.