Abstract: Switch, forming part of a mail sorting device and comprising, according to the invention, one or two rotatable or translatable switch vanes (7), which are driven, by way of one or more curve followers (6, 22) and one or more curve discs (8, 23), by one electromechanical converter, e.g. a tachometrically controlled direct-current servomotor (12). In this case the transmission ratios have been chosen in such a way that the external (virtual) mass moment of inertia is about equal to the internal mass moment of inertia of the motor. The invention can also be utilized for other quickly intermittent drives.