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. 26, 2002
Filed:
Jun. 02, 1999
Masaaki Murase, Aichi, JP;
Takashi Mizukusa, Aichi, JP;
NGK Spark Plug Co., Ltd., Aichi, JP;
Abstract
A gas sensor includes a casing which covers a sensing element and includes two cylindrical members. The cylindrical members are axially disposed in such a manner as to overlap each other. Examples of the cylindrical members are a protector (outer member) and a protector attachment portion (inner member) of a metallic shell . A diameter-reduced portion is circumferentially formed on the outer member through, for example, caulking. A weld zone is circumferentially formed at the diameter-reduced portion so as to weld the outer member onto the inner member . Through formation of the diameter-reduced portion , a gap between the outer member and the inner member as measured at the position of the weld zone is reduced, thereby improving adhesion therebetween. As a result, possibility of a weld defect arising can be suppressed. Further, attainment of a good welded state does not require the practice of dimensional control of the inner and outer members; particularly, strict dimensional control of the difference between the bore diameter of the outer member and the outside diameter of the inner member. Hence, production efficiency or yield of gas sensors is improved.