Abstract: A mechanism for actuating a universal bar of a typewriter from a continuously rotatable drive shaft comprises a principal lever cooperating with the universal bar and carrying a catch able to occupy an active position in the trajectory of a peripheral projection of the drive shaft and a rest position out of this trajectory. The principal lever additinally carries a locking lever cooperating with a control lever of the catch, the latter being connected to the control lever by a spring biasing them relative to one another into an angular position defined by abutments. A fixed stop is disposed in the path along which the control lever moves during an actuating movement of the principal lever in response to engagement of the catch by the projection. When the control lever abuts this stop, it returns to a position for locking the catch while the catch is still in engagement with said projection.