Only marking on this is "KEX" Patent Pending. KEX comes up on Google with tire repair tools but nothing on history or anything like this. Very strong spring (takes 2 hands squeezing hard to open) opens jaws a little bit and release makes it grab tight. The golf T you see grabbed in it is about as big as it will go, so maybe 3/16" max, much smaller than valve stems. If it said Bell System I would say it's a linemans wire pulling tool? Anyone?
Just a guess; For pulling tire plugs/patches tight to the inside of the tire? (from the tread side)???
I've seen stretchers to push or pull the bead out of the way, and this make the tread area flatter for a patch. that would be my guess.