Quick acting coupling for the disconnectable connection of two pipelines

This quick coupling comprises first and second elements capable of fitting into each other along a main axis of the coupling, the first element comprising at least one ramp (40) for receiving a part (20) in radial projection of the second element to lock these elements in passing configuration of the connection. The ramp (40) or the projecting portion (20) is formed in or integral with a ring mounted on one of the elements, being free in rotation and fixed in translation along the axis (X-X ') then the ramp (40) forms a first seat (406) for locking the projecting portion (40) in the passing configuration of the connector and a second seat (411) axially offset from the first (406) in a direction of opening of the coupling, for locking the protruding part (20, 21) in the decompression configuration of the fitting. Locking is achieved by essentially axial movements of the coupling elements relative to one another.