A feeding roller for feeding fibrous sliver in a textile machine has an axial hollow into which an end portion of a driven shaft of the machine extends. A circumferential surface portion of the shaft defines with a corresponding portion bounding the hollow of the roller a circumferentially extending gap which tapers or converges in both circumferential directions. Located in a recess at the widest point of this gap is a cylindrical coupling member which extends into the gap so that, when relative angular displacement of roller and shaft occur, the coupling member will become wedged, in one or the other narrow end of the gap and thus connect the roller and shaft for joint rotation.