Patent ID: 8677804

Claim:
A contact member for a gas sensor in which an electric connection to a sensor element is obtained by pinching and fixing said sensor element in an inserting port formed by a pair of housing members, comprising: a constraint member which is provided so as to surround an outer periphery of said pair of housing members and has a constraining function of constraining a displacement of said pair of housing members within a predetermined range; and an annular member which is provided in an outer periphery of said constraint member, wherein said pair of housing members and said sensor element are brought into pressure contact, and said sensor element is pinched and fixed by said pair of housing members in a state that an electrode terminal provided in said sensor element comes into contact with a contact point member provided in said pair of housing members, due to contractive deformation of said annular member with receiving an external force in a state that said sensor element is inserted in said insertion port, said constraint member constrains a displacement of said pair of housing members within a predetermined range before said sensor element is pinched and fixed by said pair of housing members, and exists in a state of being pinched between said annular member and said pair of housing members without generating any reaction force with respect to said external force, after said sensor element is pinched and fixed, said constraint member is constructed by a first member and a second member, said constraint member is provided with two sets of engaging mechanisms which engage said first member and said second member, each of said two sets of engaging mechanisms is constructed by an engaging part which is provided in one of said first member and said second member and an engaged part which is provided in the other, the engagement of said first member and said second member causes the constraint of said pair of housing members with said constraint member such that said pair of housing members and sensor element can move within the predetermined range, and said two sets of engaging mechanisms are disengaged when said sensor element is pinched and fixed.