Jamie yours is an interesting question, as there were three different floor tools supplied with the Constellation as time progressed. Two were used for about 10 years each, one after the other. The final one, the pedal tool, was not used on this cleaner for long but was of course used on a good deal of cleaners on sale both at the same time as and after full discontinuation of the Constellation.
Originally the floor tool was mounted on rollers at the front of the tool. Early cleaners had a long row of rollers along the length but a later and more common style of this tool had two small rollers, one in each front corner. A red plastic strip assisted in the removal of threads and a spring loaded brush stripe moved up and down inside the head. For a more firm cleaning action, the brush strip could be locked firmly in place. It could also be locked out of the way altogether, but the instructions didn't ever seem to mention this. Unless of course my memory fails me yet again and it was the locking the brush out which was not mentioned. Either way, there were three options for the brush strip.
When the emerald green Constellation went into production around 1970, Hoover dispensed with this floor tool in favour of the style which could be used with brush side down for floors, or flipped over to the smooth section for carpets. I am sure a good deal of people used these tools brush side down for carpets to aid cleaning performance. Like I say, this tool was used for about the next ten years or thereabouts, it may possibly have been a little less. The pedal tool which was being supplied with the top model Freedom cleaner was used as the third and final choice. As time progressed even further into the early part of the 1980's, so Hoover used the same plastic tool kit on the Constellation, as was supplied with both Freedom models which flanked the Constellation in the cylinder range for this period.
Of all of the tools, I liked the pedal style the most as I felt it had good surface contact with carpets and also a good set of bristles for floors. My least favourite was the original floor tool. I don't think it was very good for carpets, but it was very easy to use. It was not at all good for hard floors and any Constellation owner would have done well to purchase the standard Hoover floor brush separately.