The rack and pinion is used to convert between rotary and linear motion. The rack is the flat, toothed part, the pinion is the gear. Rack and pinion can convert from rotary to linear of from linear to rotary.
No iFrame ‘;
Using HTML 5 ‘;
This is the third draft on the rack and pinion animation. It should display in either Flash or HTML5 depending on which browser you are using and should be visible on a wide variety of platforms.