We had the same idea. It doesn't look like your mechanism is finished. The top spins, you move up the first bar, and from there what? The bottom one is too far down to grab onto the bar to pull you any further. The way this mechanism is right now by itself, you've got yourself an intricate 10 point climbing mechanism at best. There's something else that you're not showing. I believe I know what it is, having designed one of these, but I'll let everyone else figure it out for themselves.

All I say is I hope you can pull it off.