The green and yellow gears idly rotate on the output violet shaft of ratchet wheel. Each gear has its pawl engaging with the ratchet wheel.
Input grey frame carrying two racks has go and back linear motion. The green rack engages with the green gear. The yellow rack engages with the yellow gear. The red leaf springs force the pawls toward the ratchet wheel.
The ratchet wheel always rotate anti-clockwise regardless of go or back motion of the frame.