A high-speed rotary dobby key mover mechanism having a main crank arm in which two keying levers that have the same arm ratio are mounted for pivotal movement on a cam in opposing positions. The adjacent ends of the keying levers cooperate with a key, while the free other ends of the key levers, which are diametrically opposite about and at the same distance from the axis of the dobby drive shaft for the dobby cooperate alternately with a single control device which is located on only one side of the main crank arm. The control device is regulated, moreover, by a logic unit.