CVT from Early Automobile

On my summer break while visiting friends in Sarasota I went to the Sarasota Classic Car Museum. In there i was pleasantly suprised to find a demo that you can play with that was the drivesystem from the 1908 Cartercar. Its a really simple friction drive CVT. Clickthrough to the YouTube video of it in action, its a nice easy way of showing what a CVT is and how it works.

Now that’s a cool video, simple maybe not, but it’s definitely a site to watch. It’s interesting to see how the CVT works on the entire system, can someone explain what the levers that are shown at the end of the video are controlling?

Yup, a very simple, nice CVT. The lever at the end controls the clutch. You’ll notice that the motor is always turning (on the far right of the screen) while the CVT stops spinning about 3/4 of the way through. As the clutch re-engages, the CVT starts spinning again.

The first lever you see early in the video controls the output speed of the CVT. That lever works a (very sloppy) 4-bar linkage to slide the wagon wheel back and forth along the disk. By driving the wheel past the center point of the spinning disk, you can change the direction of the output, giving a reverse “gear” as well.

I know I’ve seen a picture/video of this design on CD as well. Ah, here it is…

Team 857’s Prototype CVT


Well the “clutch” actually just moves the whole metal disk in and out, engaging the “wagon wheel”

Yeah its sloppy, its a pretty old demo of an almost 100 year old car. But it was wicked fun to play with.