Explain a Garden Cultivator’s Wheel

Several years ago, I acquired a 2-wheel garden cultivator powered by a 1 hp engine. If was manufactured by Simplicity Co. and sold by Montgomery Ward & Co. in the late 1930s and early 1940s.

I have restored it to working condition, but I’m puzzled by the 13 studs that have been welded to the inside of the right side wheel. This is not a factory addition. The studs are 7/16-inch in diameter, 1 inch long and spaced at 1-3/4-inch intervals around the perimeter of the wheel rim.

What I would like to learn is, what did they do? How did it work? What did it work with? I would appreciate any information about this modification of this tractor.

Thanks for a great magazine.