Crank 1 rotates about fixed axis x-x and is connected by a turning pair to disk 2 . Disk 2 slides with its slots a along segments 3 and 4 which turn about fixed axis y-y. When crank 1 rotates about axis x-x, segments 3 and 4 oscillate about axis y-y under the condition that the axes of all the kinematic pairs intersect at a single point.
$985$LG,4L$