Technical What is this tool?

I bought a toolbox full of stuff at a swap meet, and this one has me stumped. WHen I squeeze the handles, the "jaws" come together. Does any know what it is?
THanks,

Joel

 

Piston ring expander, makes it easy for a novice to install rings without breaking any.

 

The old ones were pretty big like that...newer versions only have the little part that grabs the ends of the ring. I have both styles, only use the newer one.

 

I was thinking piston ring expander, but it shrinks when you squeeze it, not expands. How is that supposed to work?

 

put an old ring in it, and see?

 

That's a really good piston ring expander. In additions to expanding the ring, it "hugs" the outside of the ring to keep it from twisting.

 

OK, now I see how it works. When the outer ends of the jaws are blocked from contracting by a piston ring, the inside jaws expand the gap. Without a ring in it, just operating it empty, it only contracts.

THanks!

 

Looks like my brother. He's a tool...

 

hammer.

 

This is what my simple old one looks like. I think I'll like this new one better