The invention relates to a converter gearing, comprising a gear rim (7), which is connected to the pivoting axis (6) of a converter box, said gear rim being engaged with at least one drive pinion (8) of the converter gearing (9) and at least one locking device, which can be pivoted to engage with and be disengaged from the toothed gearing of the gear rim, (7) in the form of a locking arm (12) that is positioned on a horizontal shaft (10) and configured with toothed gearing (11). The aim of the invention is to improve said locking device. To achieve this, the shaft (10) of the locking arm (12) is mounted in at least one terminal bearing (13, 13′) and the locking arm (12) can be engaged with and disengaged from the toothed gearing of the gear rim (7) in a non-positive manner, preferably by means of active force elements (14, 14′) in its end regions. In addition, the shaft (10) of the locking arm (12) is mounted in the housing of the converter gearing (9) by means of two eccentric bushes (4, 5), which rotate freely within one another, at each of its ends. The mounting is configured in such a way, that by the independent rotation of the same, an ideal mutual engagement position of the two interacting toothed gearing regions of the locking device (12) and the gear rim (7) can be set.