Wow!!! Maui, you've managed to find an ultra rare W. E. Snediker patent no. 686,484 XL Rapid vise. I believe it may be the first one show-cased on the internet. It was manufactured by about -3- different companies, with the last one being the G.M. Yost Mfg. CO. until around 1909.
You've got a model no. 50, as seen in the 1903 catalog scan below.
It has a very unique rapid transit device, described and illustrated in the magazine scans below.

GJ member
Mark Stansbury already has some historical information about the inventor in the link below.
http://vintagemachinery.org/mfgindex/detail.aspx?id=11522
Here's the patent link.
https://pdfpiw.uspto.gov/.piw?PageNum=0&idkey=NONE&SectionNum=3&HomeUrl=&docid=0686484
Please take some time and upload some detailed photos in good lighting so we can have some quality photo's for record. Also, please reach out to KMScott, so that he can add this information to the "Vise Spreadsheet".
I knew that was a really special vise! I could smell it all the way from Chicago.
Vise on!