Thanks for the link David!
Well, that really answers my question!
Fascinating layout - the handle actually has two air channels, one sucking air up from the floor into the bag, and another from the bag back down into the base where the suction originates. It's a bit of detour for the air to get from the carpet to the motor - but I guess it works and gives you an easy way to plug in a hose for attachment use!
As the little comedian on "Laugh In" used to say: "Verrrry Interrrresting......."
