These clutches have rollers contained in a cage which is connected to the operating cam. The cam is sprung loaded to push the rollers up the ramp to provide drive, but if the cam is stopped by a trip pawl it fires the rollers out of engagement, thereby disengaging the drive. Clutches can provide a single revolution, multiple revolutions or a fraction of a revolution from a constantly rotating input. Extremely accurate positional control is provided with no accumulative error. Two types of clutch are offered - the BAT series for maximum torque capacity, and CTK series for higher speed applications and replacement on existing machinery.