gear system that changes direction

I love it! But where can you use it?

In a one step forward two steps back machine.

One application I can think of is in a washing machine, where you want the tub to spin back and forth.... with a gear like this you could have a motor that only goes in one direction, which might be more efficient.

that would be handy for tapping threads

Excellent idea, the smaller gear can be used to screw in the tap and then back it off.

Man, this is awesome! Not from an engineering point of view, but an innovation... Would there be any way of making both cycles the same speed?

think about something

why am i getting negative feedback. i was being serious. what are the real world uses of something like this.

strgzr53, I didn't give you any negative, but I give my 2 cents.

Real world uses?

This looks like Art to me. Not cutting edge technology.
My educated guess is that mechanisms as basic as this have been in use for decades.

It looks like an instructional device.

I think it is used to spark interest in mechanical minds.

A shuttle conveyor.