Input: blue oscillating lever with a threaded portion on its shaft.
Output: yellow inner cone disk rotating interruptedly.
The light friction of pink spring-loaded pins keeps the green outer cone disk (split for easy understanding) from rotating with the lever at moment when the lever changes it motion direction. Thus the green disk moves a little like a nut back and forth along the threaded portion of the lever. This motion creates or removes the contact between two disks (engagement or disengagement).
Thread direction (right-handed in the video) decides the transmission direction.