Over the years I've picked up four different sets of these blasting pliers. Mine are all old, from the early-to-mid 1900's. Most likely from hard rock mining operations. The more modern ones I see on eBay seem to be mostly for military demolitions. They tend to refer to them as "cap crimpers". Old or new, the intention appears to be pretty much the same: Design a single tool that can cut the fuse wire, crimp on the blasting cap, and poke a hole in the explosives for the cap to be placed.
Here are a few frames from a military training paper that explains the idea:


....And here are a couple of my old blasting pliers. The first one is an "Atlas No. 3." Atlas Powder Company was formed as a result of a court order that broke up the near-monopoly that the DuPont company had on smokeless powders and dynamite. Apparently Atlas sold tools and accessories in addition to their powders. I've seen pictures of an "Atlas No. 2" tool, but I don't own one. Not really sure how old this guy is:

You can see the crimper jaws are on the end, while a large cutter and a small cutter are on the sides. The end of one handle is a poker to start the fuse hole, while the other handle ends in a screwdriver.
Another tool I've got is this all-brass one. It has crimper notch near the pivot, then a fuse cutter notch next to that. On the end of one jaw there is a hole, with a narrow slit in it. The other jaw has a sharp steel blade in it. The blade can either cut the fuse, or slit the insulation from it, depending on which notch you use.



It was patented by a Mr. Harry Prince in 1922.
