I have an old Case side delivery rake, and a question. The lever in the middle changes the pitch of the teeth, I know that, but what for?? Also, What is the function of the slotted doo-hickey that this lever rides over, and what is missing in this picture? It seems like there should be some sort of mechanism to engage these slots ( it came with the u-bolt ). The rake works well for what I need, though I am curious. Wondering in Wisconsin, JP.