Patent ID: 7497482

Claim:
A pipe joint comprising a first and a second tubular joint member of synthetic resin, a synthetic resin gasket interposed between abutting portions of the joint members and screw means for joining the joint members, the pipe joint being characterized in that the first joint member is provided in an abutting end face thereof with an annular recessed portion having an opening remaining therein with the gasket entirely fitted therein, the second joint member being provided with an annular ridge on an abutting end face thereof, the ridge being fitted in the opening of the recessed portion with the gasket fitted in the recessed portion, an outer surface of the ridge of the second joint member being pressed against an inner surface of the recessed portion of the first joint member with the gasket interposed between the surfaces in intimate contact therewith approximately over the entire surface areas when the pipe joint is properly tightened up, a portion of the abutting end face of the first joint member positioned radially inwardly of the recessed portion being then in intimate contact with a portion of the abutting end face of the second joint member positioned radially inwardly of the ridge approximately over the entire surface areas thereof, a portion of the abutting end face of the first joint member positioned radially outwardly of the recessed portion being then in intimate contact with a portion of the abutting end face of the second joint member positioned radially outwardly of the ridge approximately over the entire surface areas thereof, wherein when the pipe joint is manually tightened up, a first gap is present between the portion of the abutting end face of the first joint member positioned radially inwardly of the recessed portion and the portion of the abutting end face of the second joint member positioned radially inwardly of the ridge, and a second gap greater than the first gap is present between the portion of the abutting end face of the first joint member positioned radially outwardly of the recessed portion and the portion of the abutting end face of the second joint member positioned radially outwardly of the ridge, wherein each of the joint members is provided at the abutting end face thereof with a flange portion, and the screw means comprises an annular male screw member having a forward end face in bearing contact with the flange portion of one of the joint members, and a cap nut fitted around the other joint member and having a top wall in bearing contact with the flange portion of said other joint member, the cap nut being screwed on the male screw member, wherein an annular clearance is formed inside the cap nut around the flange portions of the joint members and has an annular spacer disposed therein, and at least one of a space between the cap nut top wall and the spacer and a space between the male screw member and the spacer has provided therein a biasing member for biasing one of the joint members toward the other joint member.