upper roller of carriage 8 the shape of the cam track formed on lever 4 is selected such that as indicated by double headed arrow 12 an actuating contact region of the lever moves upward when carriage 8 moves away from pivot 5 double headed arrow 12 is located on line of action 13 of the actuation force of the clutch when carriage 8 moves towards pivot 5 lever 4 with its actuating contact region moves downward carriage 8 with the rollers and the cam track on lever 4 form a cam mechanism integrated in lever system 1 21 and 31 the opposing arrangement of pivot 5 and carriage 8 or rather the cam mechanism causes an actuation three of the clutch also referred to as an engagement force to be distributed between carriage 8 and pivot 5 as a result the overall force for actuating the clutch may be lower than in the case of a lever actuator as described in the international patent application publication no wo 2008 154896 a1 for instance in lever system 1 shown in fig1 double headed arrow 16 indicates distance r r between carriage 8 and line of action 13 of the actuation force double headed arrow 17 indicates distance l 1 between line of action 13 and flexurally elastic region 14 further double headed arrow 18 indicates distance l 0 between line of action 13 and pivot 5 flexurally elastic region 14 has flexural rigidity c t indicated in newton meters per rad based on flexural rigidity c t the effective actuation rigidity or engagement rigidity of lever.