SEPARATION-PREVENTION COUPLING

摘要

PROBLEM TO BE SOLVED: To prevent an excess shrinkage of diameter of a separation prevention ring by applying no local force for removing it to the inside of a receiving port even if a force for removing it is applied in the state that a connection part of the removal-prevention coupling is bent. SOLUTION: The separation-prevention coupling is provided with a groove 1 for separation-prevention ring in which a first space part 8 continuously provided on an inner periphery surface of a receiving port 2 from an opening 3 to a depth side and having a peripheral surface parallel to an axis, a second space part 9 having an enlarged diameter toward a depth side and a third space part 10 having an inner periphery surface parallel to the axis are formed. A removal-prevention ring 6 having an outer periphery surface 16 parallel to the axis and being engageable with an outer periphery surface of an insertion port 11 is axially movably attached to the groove 1 for separation-prevention ring. A taper part 7 having a diameter subsequently enlarged from the opening 3 side to a depth side is provided on a tip end of the outer periphery surface of the separation-prevention ring 6.