Abstract: A switch machine which is connected by two throw rods to the respective switch points to be operated includes an internal locking arrangement which includes two holding elements pivotally mounted on the respective throw rods and accommodated between a sliding member and a displacement member of the switch machine which are disengageably connected to one another. Each of the holding elements has a free end which is enlarged by two tongues respectively extending toward the sliding member and the casing of the switch machine. Depending on the position of the sliding member, the tongues are received in the associated recesses in the sliding member or in the casing to thereby either lock the throw rods in their positions relative to the casing or to entrain the same for movement with the sliding member.