Pin wheel 1 with nonsymmetrically located pins b and concentric locking surfaces a-a and c-c rotates about fixed axis A and periodically meshes with teeth d of sprocket 2 which rotates about fixed axis B. Sprocket 2 has nonsymmetrically located teeth d and identical concave surfaces e. When driving pin wheel 1 rotates continuously, driven sprocket 2 rotates intermittently with dwells. During the dwells, locking surface a-a or c-c engages the corresponding concave surface e to prevent unintentional rotation of sprocket 2. The two periods T_r of rotation of sprocket 2 are not equal, nor are the two dwell periods T_d. When the part of pin wheel 1 with four pins is in engagement, sprocket 2 turns through the angle (2/3)π; when the part with seven pins is in engagement, sprocket 2 turns through the angle (7/6)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 periods T_r is i₁₂=r₂/r₁ where r₁ and r₂ are the pitch radii of wheel 1 and sprocket 2. Wheel 1 and sprocket 2 rotate in opposite directions.
$2597$PG,D$