I have recently found a large-scale means of making raised growing beds, these seem to be primarily for carrots and the like, but it's got me wondering:
Instead of a hiller/furrower, what about something like this to go behind a tiller? Maybe have a chain drive to the roller to spin it.
I have very shallow, high clay soil here, and something that gives me more growing depth would be welcome.
The video below gives the best overview of operation.
http://youtu.be/Tuv7H5_Wy_w