Abstract: A device for positioning the beginning of the line in a typewriting machine of the kind with a typing element carried by a carriage (1) includes at least one margin stop (13) for the carriage (1). This margin stop (13) is fixed on a mounted margin rack (19) sliding against the action of a spring (24). An escapement pawl (5), working with a rack bar (10), is carried by the carriage (1). A universal bar (11) disengages the pawl (5) from the rack bar (10) at the time of the return of the carriage (1) and frees the pawl (5) at the end of its path. In order to avoid a situation where the pawl (5) falls in a displaced notch of the rack bar (10), the device is in addition supplied with means for locking the pawl (5) in a disengaged position relative to the rack bar (10) during the movement of the sliding margin rack (19).