Fairfax cleaners have been made since 1962.
They were a big seller during the 1960's. The dirt container used to be stainless steel. So was the dolly.
They use a paper disposable bag, a paper flat filter over the top of the dirt container, a cloth filter under the motor, and an air scent dispenser after the motor.
They didn't always use a by-pass motor. Most (but not all) were two-speed motors.
They were very high quality machines, about as expensive as a Filter Queen or Rainbow. They started life in Washington DC, and ended life in Texas. Along the way they were in St. Louis as well as Canada.
They never made their own power nozzle. They have used Air-Way, Hoover, Eureka, and Wessel-Werk nozzles (private labeled for Fairfax).
The design of the motor unit only changed when they started using a by-pass motor. They are still basically the same machine they've always been - only the attachments have changed. The same bag and filters fit all models.
I own one of all the different incarnations of the Fairfax.
