I'm building a light fixture out of some old junk I've collected over the years. This will be part of it. It is cast iron, about 20" across. Judging by the square nuts and bolts, it is about 100 years old, and probably part of something agricultural. The arms are spring loaded, and—before it had rusted solid—it appears that you would pull the arms back to disengage them from the central piece, allowing the central piece to move forward or back. Perhaps it was some sort of tensioning component. Anyone have a clue? Thanks.


