Patent ID: 6898961

Claim:
A gas sensor comprising: a gas sensing element having a gas-exposed portion; a hollow housing made of a one-piece member which has a first and a second end and an outer wall extending between said first and second ends, said housing holding said gas sensing element therein so as to arrange the gas-exposed portion outside the housing for exposure to a gas to be measured; a protective cover installed on the first end of said housing to cover the gas-exposed portion of said gas sensing element; leads connecting with said gas sensing element, extending from the second end of said housing for electrical communication with an external device; an insulator retaining therein said leads connecting with said gas sensing element; and a metallic cover in which said insulator is held, wherein said hollow housing has an inner chamber and wherein the second end of said hollow housing comprises an open end, a buckled portion, and a joint portion, the open end being crimped inwardly of said hollow housing to elastically press a metal ring, a sealing member, and an insulating member disposed within the inner chamber to hold said gas sensing element in the inner chamber, the buckled portion resulting from inward crimping of the open end, being closer to the first end of said hollow housing than the open end, and bulging outwardly of said housing, the joint portion being closer to the first end of said hollow housing than the buckled portion and greater in wall thickness than the buckled portion, and wherein said metallic cover has an end portion fitted on the outer wall of said housing, a circumferential portion of the fitted end portion of said metallic cover being welded to the whole of a circumference of the joint portion of said housing so as to dispose the inwardly crimped open end, the buckled portion, and the joint portion of said housing inside said metallic cover.