US Patent 7264281 Connection means for high pressure fluid ducts

Connection elements include a coupling defining an internal channel having an end segment possessing an insertion opening for insertion of an endpiece and provided with members for retaining the endpiece in leaktight manner therein. The members include an annular axially compressible sealing element that is mounted in the coupling to have one face serving as a bearing surface for a terminal face of the endpiece, and an annularly-shaped retaining element elastically deformable in a radial direction that is received in an inner groove (21) of the end segment to have an inner circumferential portion projecting through an opening of the inner groove so as to be received in an outer groove of the endpiece. The inner groove has a concave frustoconical flank beside the opening of the end segment to form members for shrinking the retaining element, and a convex frustoconical flank on its side remote from the opening.