Looks like a simple indexing device

pipped at the post

Edited By Dennis R on 21/03/2023 20:35:45

I agree with what's been suggested, but I would add it looks like it's designed to fit a lathe toolpost and hold a gear blank above the spindle height so a gear cutter can be held in the spindle. The part projecting down under the two hex headed bolts at the top looks toolholder sized.

As others have said, a simple dividing head. By changing the gear wheel a different division is generated. Often uses change wheel gears from a lathe. I have a similar tool but with 2 other spindles to use up to 3 gears for compound trains. Noel.

As well as a home-made general purpose divider my guess is that it would be handy as a quick, home-made way of cloning any given gear that could fit on the left hand side – guessing that the precision wouldn't be wonderful – it looks like that pin is spring loaded rather than being threaded to lock in place – but might have been enough for some things.