A sealed coupling comprises first and second endpieces. Beyond its end, the first endpiece has a U-shaped axial extension provided with a transverse groove. The second endpiece is provided with a radially outwardly extending and substantially circular flange. The flange is suitable for being engaged in the groove during relative transverse displacement of the two endpieces. The end of one of the endpieces is provided with a circular sealing gasket. The second endpiece has a resilient collar with a radial face that bears against the second radial wall of the groove, and one of the two endpieces has a projection situated for penetrating into a setback in the other endpiece.