hi ! i dont know what this tool was used for and i really want to know more about it.
I can read on
Thompson MFG.CO
MEADVILLE.PA.           PAT. JULY 13 1920

thanks for your help !

Not enough picture. Looks like a nipper or plier of some kind.

i put more picture thanks for the fast reply !

OK- not a nipper.

Looks like some sort of valve spring compressor to me.

Based on length, looks like it would hold a hot rivet nicely for insertion into a girder on an iron work job.

Can you read the patent number well enough to look it up on the patent website?? Or is that the patent date?

DATAMP only shows 3 patents for that date, and none are that tool.

A giant pair of Cleco pliers?

Bearing in mind that rivets for structural steel were worked red hot, I think the amount of manipulation required to get a rivet into position in a tool like this before inserting it tnto the hole would be impractical. Reading up on Google books about structural riveting (Railway Track and Structures Cyclopedia - 1921) it seems there were rivet pitching tongs and rivet sticking tongs. After the rivet was heated in a forge, the rivet heater picked it up with the pitching tongs (one curved and one straight jaw) and threw it to the rivet handler. The rivet handler caught it in a metal can or bucket, grabbed it with the rivet sticking tongs (similar to the pitching tongs, but with both jaws cupped to receive the rivet shank and bent upward at a 45 degree angle from the plane of the handle to allow the rivet handler to place the rivet squarely in the rivet hole when the jaws are flat against the structural member) and placed it in the hole. The rivet handler then bucked up the rivet with a dolly while the rivet driver upset the rivet with a rivet hammer (later a pneumatic hammer) and formed the head with a rivet set, or snap.

That's one of the things I like about this part of the forum, I get to learn all kinds of interesting things while trying to figure out what a tool might be for.

Interesting tool.   As I've worked with hot stuff, I can say it has a blacksmith shop background due to the long handles, required when working at the forge.  Also the handles look hand worked, not machine made.   Another bit of terminology here is the handles were called reins, as horses were controlled with reins, not handles.   The head definitely looks like one made to handle a rivet or bolt, a carriage bolt?    If I were to make a carriage bolt,  this would hold it securely,  to move it to a die for threading?   For more work done to the shank?  I'm guessing a special use tool made for a particular job that we might discern in the future.   

I don't know what it is & also struck out on a quick Google search last night, but a nice example just recently sold on ePay & more photos can be found here:

http://www.ebay.ca/itm/Blacksmithing-Adjustable-Rivet-Tongs-Thompson-Mfg-Co-Meadville-PA-Forging-Tool-/151062740009

That's it!

From various index's, Thompson made various auto electrical tools, comutator scrapers, battery terminal pullers, etc, but, they later seem to have moved into things related to industrial pumps, and perhaps other things as well....

Perhaps battery tongs?

Patent no. 1,346,306 ( https://www.google.com/patents/US1346306?dq=patent:1346306&hl=en&sa=X&ei=s3DkUeL4F6r-igL9mIHIBw&ved=0CDYQ6AEwAA ) battery tongs. --  Gotta get ready for work, but will put the patent in DATAMP in the next day or so.

thank you everyone for you anwser !!

Interesting. While searching Google, I did see that Thompson Mfg. made battery tongs, but didn't look any further into that angle since I couldn't see any reason for the long handles if you were using them on a battery post. But that's clearly what they are. The ones in the picture rusty posted have relatively long handles as well. Anyone out there familiar enough with old storage batteries to know why these have such long handles? Were they needed just for leverage, or was something that you didn't want to be too close to (splashing, arcing, etc.) liable to happen when you pulled the terminal off?