Ran across this Australian style stick rake on a Dressta TD20. I've seen this style rake with cutting edge welded in between the teeth before but I haven't seen one like this with chain threaded through the teeth. Is it supposed to cut roots underground or is is for clearing up small debris on the surface?
Very similar to US Electric Utility Coal pile dozers, they have much wider blades and ripper teeth at bottom to keep the coal stirred up as it will try to self ignite when in large piles.
The idea of the cutter bar, generally, is to hook out small regrow that would otherwise just fold over under the rake and stand up behind you. They work OK for that purpose, but can be a pita with sticks caught up in the tines and the cutter bar riding over timber, so it would be very useful to be able to remove the bar when there was no need for it . I've never seen chain used before, but it might just work alright. These rakes are always operated floating on the surface.