Hoover 'Junior' vacuum cleaner, 1936.
© Science Museum / Science & Society Picture Library
This popular vacuum cleaner sold in great numbers. Its design was so sound that the basic vacuum cleaner and the principle on which it works have not changed much since. The suction nozzle at the foot of the cleaner holds a metal cylinder which includes a line of bristles and a carpet beater and this is rotated by a belt-drive from the spindle of the fan motor. The carpet is simultaneously beaten and brushed and the dust is sucked into a large external dust bag (made of oiled heavy cotton).