Disk 1, subject to a constant torque and turning about fixed axis B, carries two pins A₁ and A₂•. Upon reciprocating motion of stop-dog 2 in the directions of the arrows, disk 1 makes one revolution to each motion of the stop-dog. The half-period of stop-dog reciprocation should be somewhat less than the time required for one revolution of the disk.
$261$SL,SD$