Another beach find that has me puzzled as to it's purpose. It's a little over 2 inches in diameter. There are real fine threads both inside and outside the center hub with that ring with the teeth on it, is threaded onto those outer threads. The only other threaded hole is the one on that little bump sticking out of the outer rim. There are 14 other holes through that outer section. but, none look to be threaded. Four of the big ones are countersunk. There are 3 patent pending dates stamped into it.....Apr 21, 1908, Aug 31, 1909, and Jan 18, 1910. It also says Pat. in USA. All ideas welcome!