I have a Fisher #4 chain vise that I have never seen anywhere else. I was told by many it was a homemade setup and recently found the original 1889 patent application on Goggle. I have searched for years to find another one of these. Amazing what you can find it you search long enough. If you know of another like this let me know.

Sorry, it's not for sale.

I have 2 of the straight leg #4's.  The leg just unscrews out of the casting, so I'd guess that the different leg is what makes yours "portable"  Still pretty heavy for that thou!  Great vises.

Yes just a leg variation on the standard Fisher chain vise.  Did the patent make any claims on other new  functionality for it?

This is the patent application for the vise by Fisher in 1883. http://www.google.com/patents/US282975?dq=fisher+vise#PPP1,M1

It is completely original. The legs are held on with wing nuts. So far it is the only existing example I have found anywhere. The Fisher & Norris Factory Museum has posted recent pictures of it on the website. https://www.facebook.com/FisherAnvils

I inherited it with my 1865 farmhouse and barn. It almost ended up being thrown out by the previous owner as they were moving out.

Neat; so the back legs are original to it.   I've done variations on that method without previously ever seeing those.

This is a new variation of Fisher products that I have never seen before.  I did not even know that such a design existed before seeing this one.  

The patent was written as a way to use the vise without it being attached to a bench.  It was a way to make it "portable", or at least able to be moved.  It did take up a lot of floor space.

It only took me 21 years to prove this was an original design. Now to find another one like it. lol