It is a two row "TILLIVATOR". Each of the house frames holds essentially a garden tiller head that is turned at a fairly high speed but very shallow, 2" or so. The way it worked is the tiller passed on each side of a planted row and tilled up any weeds or grass leaving only a narrow 6-8" space for the plants you wanted to remain growing. THE plows plowed out the middle. It did a good job of grass removal but was much slower than a cultivator. Chemical applications turned them into an extinct dinosaur not many years after they came to be in the mid 60's if I recall correctly the date I saw the first one of those.
