Until the model 285 (same product as the Royal 801) came out in 1955, Electro-Hygiene uprights were always straight-suction cleaners, since at the time the designers couldn't think of a viable way to place the scent chamber on the nozzle with a revolving brush.
In the end, a separate scent chamber accessory was designed that was attached in place of the standard belt cover.
~Ben
