Crown gear 1 and pinion 2 rotate about fixed axes A and B-B. Crown gear 1 has four concentric rows of teeth. Pinion 2 is rigidly attached to slider 5 which moves along shaft 3. By shifting slider 5 along shaft 3 pinion 2 can be brought into engagement with one of the rows of teeth on crown gear 1. For a single angular velocity of crown gear 1, pinion 2 can have either of four angular velocities. Shaft 3 rotates in the same direction when pinion 2 engages rows to the right of point A; its direction is reversed when pinion 2 engages rows to the left of point A. Slider 5 is shifted by lever 4 to which it is connected by turning pair C. Slider 5 is indexed in each of its positions in which pinion 2 engages a row on crown gear 1 by means of slots a in lever 4 and tooth b mounted on the base.
$2341$SG,3L$