This angle doubling drive will enlarge the oscillating motion of one machine member into an output oscillation of the other. If gears are employed, the direction of rotation cannot be the same unless an idler gear is installed. In that case, the centers of the input and output shafts cannot be too close. Rotating the input link clockwise causes the output to follow in a clockwise direction. For any set of link proportions, the distance between the shafts determines the gain in angle multiplication.
The video shows case when the green link rotates 90 deg., the blue rotates 180 deg.