Input: grey screw.
Output: orange crank shaft.
Transmission ratio between the coaxial input and output is -1 (rotating in opposite directions with the same velocity).
The grey screw of h2 lead is in mesh with internal thread of the green nut-screw.
The base having internal thread of h3 lead is in mesh with external thread of the green nut-screw.
h3 = 2.h2
The threads are right-handed.
A pin fixed to the green nut-screw slides along longitudinal groove in the orange crank shaft hole.
In two last scenes one fourth of some links are cut off for easy understanding.
This mechanism needs to verified in practice.