Devices (10,110,150,200 and 250) include roller clutches for controlling rotational phase change of a camshaft between full advance and full retard positions and positions therebetween. Each of the devices includes sets of selectively operative rollers such as a set of rollers (36) for preventing phase retard and a set of rollers (34) for preventing phase advance. Devices (10,110,150 and 200) have pairs of rollers 36,34 acted on respectively by ramp surfaces (32d,32c) defined by a common flat surface. An annular member (32) defining ramp surface (32d,32c) is mounted with free play relative to an axis of the camshaft. Device (110) includes a splitter spring (112). Devices 150 and 200 include internal actuators (152,202).