Input: green crank.
Output: blue ratchet wheel.
Both go and back motions of the crank make the wheel rotate in the same direction. Yellow pawl pushes and orange pawl pulls the wheel.
Violet springs maintain contact between pawls and ratchet wheel.
STEP files of this video:
http://www.mediafire.com/download/raoyp1igpzinie1/Ratchet20STEP.zip
آی-ویدئو