Driving pulley 1 is rigidly attached to gear 3 and they rotate together about fixed axis A. Gear 3 meshes with gear 4 which is rigidly attached to gear 5 and they rotate together about axis D of lever 6. Lever 6 turns about axis A. Gear 5 meshes with alternating external and internal engagement with pin wheel 2. When pulley 1 rotates continuously in one direction, gear 5 first rotates pin wheel 2 in one direction and then in the opposite direction. Reversal occurs after each angle of rotation of almost 360° in one direction when member 7 switches gear 5 from external to internal engagement (and vice versa) with pin wheel 2. Stops b limit the swing of lever 6 during reversal.
$2595$PG,ML$