JOINT

PROBLEM TO BE SOLVED: To provide a joint preventing a union nut from unpreparedly coming off of a main body and capable of easily attaching and detaching the union nut to the min body without using a tool. SOLUTION: The joint composed of a main body 1 including a flange 11 projecting outward and the union nut 2 inserted on the main body 1 rotatably in a regular and a reverse direction and including a diameter reducing part 20 and making the flange 11 and the diameter reducing part 20 in a locking condition when the union nut 2 is moved to be pushed in to an axial direction of the main body 1. An elastic ring 3 abutting on the diameter reducing part 20 when the union nut 2 is moved to be pushed out of the main body 1 is provided in a circumferential groove 12 formed on an outer circumference surface of the main body 1. When further pushing out force is applied at a time the elastic ring 3 abuts on the diameter reducing part 20, an outer circumference part of the elastic ring 3 elastically deforms and passes through the diameter reducing part 20. COPYRIGHT: (C)2005,JPO&NCIPI