is a suspension/support thing for old timey medial procedures. like you sit on it and put a body part on it and it hold you while they cut it off or drain your fluids or whatever
Alright. What can we tell? It is spring loaded, so it moves. It has a stand, so it is portable and possibly rotates. The iron ball part is curious as are the arm holding it. The rings at the moving end of the spring are oddly positioned. The rod with the cylinder seems like some kind of stop for the spring, but why attached to the iron ball? Egg catapult and and clay pigeon slinger are "warm". I deduce that it either throws something (catapult/slinger) or has something to do with birds (egg/pigeon). I have no idea.
OK, you made that easier... Target Ball, glass balls for the fun of it Glass ball target launcher. Primitive skeet launcher.