A device for the transmission of one-way torque comprising an outer annular member having a plurality of radially inwardly projecting teeth each comprising a driving surface and a cam surface, and a shaft concentrically mounted with respect to the outer annular member and comprising a plurality of drive elements each having a driving surface and a cam surface. Rotation of the shaft or outer annular member in its driving direction causes engagement of a driving surface of at least one drive element with a driving surface of at least one tooth thereby resulting in joint rotation of the shaft and outer annular member. Rotation of the shaft or outer annular member in its non-driving direction causes engagement of the cam surface of at least one drive element with the cam surface of at least one tooth resulting in additional relative movement, substantially radially, between the drive element and tooth, thereby preventing rotational movement being transmitted between the shaft and the outer annular member.