Vacuum cleaner tycoon Sir James Dyson, whose bagless machine has conquered the world, today saw off a rival Korean product after a battle in the High Court.

Mr Justice Arnold ruled that patents covering Samsung Electronics' three cyclone cleaner were invalid because they were "obvious" developments after Dyson Technology developed the original machine with two cyclones.

Sir James said of his victory: "Samsung aped our patented technology and cynically claimed to have invented it.

"We may not be a commercial giant like Samsung, but we will vigorously defend all the technology we have worked hard to develop and protect.

It's a win for engineers and inventors."

The company, based in Malmesbury, Wiltshire, exports its cleaners to 45 countries throughout the world.

In 2000 Sir James won a patent infringement case against Hoover.