Pin wheel 1 with pins a rotates about fixed axis A and periodically meshes with teeth d of sprocket 2 which rotates about fixed axis B. Pin wheel 1 has concentric locking surface b and sprocket 2 has two concave locking surfaces c. When driving pin wheel 1 rotates continuously, driven sprocket 2 rotates intermittently with dwells. During the dwells, locking surface b engages one of concave surfaces c to prevent unintentional rotation of sprocket 2. To each revolution of wheel 1 sprocket 2 turns through the angle ϕ₂=π. The profiles of teeth d of sprocket 2 are along curves which are equidistant to an epicycloid of a circle. The transmission ratio from wheel 1 to sprocket 2 during the rotation of sprocket 2 is i₁₂=r₂/r₁<1 where r₁ and r₂ are the pitch radii of wheel 1 and sprocket 2. Wheel 1 and sprocket 2 rotate in opposite directions.
$2609$FG,D$