Locking device with a pulse-controlled rotary lock

A locking device for preventing movement between two elements that are mounted to move relative to each other, the locking device comprising a lock, an angular indexing mechanism, a pulse-controlled actuator and a spring member, the lock being mounted to rotate relative to one of the two elements around an axis in order to present successive angular positions for locking and for release in which the lock alternates between preventing and allowing relative movement between the two elements, the lock being constrained to rotate around the axis with a selector of the angular indexing mechanism actuated by the pulse-controlled actuator arranged to push the selector against the spring member in order to cause said selector to turn around the axis on each pulse and thereby cause the lock to pass from one angular position to the other without generating any translation of said lock along the axis.