This is a Star Tool Co ?

[jimwrench]

 This is a Star Tool CO ------?
Don't know what this is but its a mighty fine one. I suppose every one has two of them in your tool box.

[EVILDR235]

A third hand ?

EvilDr235

[rusty]

Can't sort out all the various companies named star tool, but I see a weak reference to a brake shoe lining installation tool...??hmm?

Very odd shape...

[ron darner]

I don't recognize this item, but have a couple of ideas that may help someone else.  First, observe that the large "clamp" feature has no fixed feature to clamp against. This makes me think that the small jaw is used first, gripping the end* of something like a belt or tape, and that the half-round notch is then set against a round item such as a pipe, adjusted, and then the tool used to stretch the part being gripped.  Imagine an upholsterer stretching fabric tapes for a seat, for example  If the adjustment were near-perfect, this might even sort of toggle, making it easy to hold tension while driving staples or tacks.  After attaching the tape, the tool could be removed, and the tape cut off, ready to be part of the next strip. 
*Gripping a fold would mean that there would be no wasted material.

[jimwrench]

 Agree that the top clamp is meant to grip something but bottom part would seem to be to push against something cylindrical. Also there is a vee shaped recess that would suggest that object pressed against has a protruding ridge.
It would be too simple for them to have gotten their patent but as Rusty said there are more Star Tool Co's than we know.

[wvtools]

It looks like a lasting cramp or clamp, but those are usually two sided.

[Lostmind]

I wonder if it could be used on old " Clincher" rims somehow. How to say with out having it in hand.