A device for coupling together two elements mounted to rotate about a common axis of rotation (X) in order to enable one of the elements to be selectively driven in rotation by the other. There are two members (3, 4), one per element, the elements being axially movable relative to each other between a remote decoupled position and an engaged position in which the members provide a rotary connection between the two elements. One of the members forms a plate (3) having a face (P) perpendicular to the axis of rotation and in which a plurality of housings (15) are formed. The other one of the elements carrying rollers (23) that are mounted to rotate about radial axes to project from said element so that each of them can penetrate into any one of the housings and provide a rotary connection between the two members.