Fluid coupling

A fluid coupling for a corrugated pipe, comprising:

• a coupling body including a front end portion, a rear end portion, an axial through hole, and a cylindrical outer peripheral surface adjacent to the front end portion, said through hole having a pipe insertion opening at the front end portion, adapted to receive an end portion of the corrugated pipe therein, and a fluid passage disposed at the rear end portion;
• a metallic seal means arranged in said coupling body inward of said pipe insertion opening, for sealing an end of a corrugated pipe;
• an internal sleeve having a front end portion and a rear end portion, and slidably mounted on the outer peripheral surface of the front end portion of said coupling body, said front end portion havaing a first tapered surface which converges toward the rear end portion, projecting axially outward from the front end portion of said coupling body;
• ring-shaped engaging members adjoining said first tapered surface of said internal sleeve, and having inside diameters reducible to less than an outside diameter of top portions of the corrugated pipe;
• a retaining means for retaining said engaging members at a predetermined position in the axial direction wherein the end portion of the corrugated pipe is pressed against said metallic seal means;
• wherein said retaining means further comprises an external sleeve overlapped and slidably engaged with respect to said internal sleeve, said external sleeve having a corrugated pipe insertion opening in its center, and an annular projecting portion at one end thereof in opposing relationship to said first tapered surface of said internal sleeve, and said annular projection portion having a second tapered surface converging toward said front end portion, said engaging members being disposed between said first and second tapered surfaces so that said first and second tapered surfaces cooperate to press said ring-shaped engaging means radially inwardly into a root portion of the corrugated pipe inserted into said pipe insertion opening when said external sleeve is moved toward the rear end portion of said body.