Identifying An Old Farm or Garden Implement?

Does anyone know specifically what this old farm or garden implement is and when it would have been in use? It appears to be some kind of cultivator or tiller. It has a wooden handle and shaft with a row of ornate metal discs along the front and also a row of discs going the other way inside. It is rather heavy. It is about the size of a modern rake.

I have looked all over the internet and have been unable to find another like it. I would appreciate any information on its age and value. Thank you.