Here are some additional photos. As far as size, that’s about a 2” x 2” x 1” steel block it is testing against. I don’t know why my dad, a carpenter, would have had this but he had a lot of odd stuff in the shop. It is possible that it belonged to my grandfather who was a pipe fitter in the Boston navy yard.
My original thought based on the point was a lathe or milling machine, but it would be for metal turning, probably in a factory, rather than woodworking. I’ve been woodworking since I was a kid in the '60s, my masterpiece being a Queen Anne Highboy with cabriole legs, and I can state with confidence that it isn’t from a woodworking device.
Whatever it is, I suspect that the intact post/rod seats into a hole, possibly one of a series, the other (broken) rod is held, and another rod goes into the smaller holes in the side of the collar where the point is, and turns the center outward to press the point into something. The purpose of doing so may be lost to history. There are countless old tools like this that were used for purposes that no longer exist. My grandfather had some odd tools many years ago that came off of the old railroad steam engines.
Seeing what’s in the cast housing might be a big help. I see that the OP is working to disassemble it, and having some success. The internals might tell the whole story.
I agree. Looks like some type of jack or spreader. It ratchets and the pointed end is forced outward. The holes may be to more quickly extend it to touch, then ratchet to start lifting or spreading. Interesting problem…
I’m sold.
TT has, I believe, uncovered the mystery. A tip of the hat to you, TT.
Well that’s interesting. Must be 1900 stuff or before.
What a great thread. I love this forum.
What a great find! Good job!
please don’t scrap this! 
I’m inclined to agree. Since it seems purpose-specific, I have to wonder too if it was used in wooden ship building, railroad work, or some other function no longer commonplace.
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Nice picture. From the style, it’s clearly a patent drawing. What is the associated patent? The “specification” (text body) would explain the use and purpose.