It's a winder of some kind. The part on the right of the photo is for controlling speed. The stub on the left is for holding a bobbin/thread spool. By changing the ratio on the right, you can control speed of winding. Based on size, I would guess for winding thread spools. There would be an arm that sits on top of the spool, and has a set of graduated shapes like the piece on the right. My guess is the feed belt is on the top, with winding spindle above the spool.