New inventions can transform entire industries, rendering existing products more or less obsolete, but they almost inevitably give rise to patent disputes. A case on point concerned a revolutionary garden hose design that solved problems of storage, weight and kinking all too familiar to gardeners since the 1950s.
The hose consisted of two tubes, one inside the other, the inner tube being made of an expandable material, such as natural rubber, and the outer tube, several times as long, made of a flexible material such as nylon or polyester. Expanding from 10 feet to 50 feet long when filled with water, it overcame problems associated with existing hose designs which had remained almost unchanged for decades.
Since the hose was invented by a man who patented it the day after testing it in his own domestic garden, it had enjoyed great commercial success worldwide and had spawned numerous similar products. The exclusive sub-licensee of two UK patents in respect of the hose launched infringement proceedings against the manufacturer of two of those rival products.
In ruling on the matter, the High Court found that, on the assumption that the patents were valid, they were infringed by both rival products. It also rejected arguments that the patents were invalid on the basis that the inventor had made his design available to the public by testing prototypes in his front garden, within sight of any notional skilled hose designer who happened to be passing by.
In dismissing the claim and declaring both patents invalid, however, the Court found that they were obvious when compared with a previous patent in respect of a self-elongating hose used to supply oxygen to aviation crew. Although that hose was used in a very different context, and looked nothing like a garden hose, it would have been obvious to a skilled person that it could be adapted for garden use.
The Court noted that the commercial success of the hose was attributable to the fact that it was a genuinely innovative product that had not been seen before. However, that did not mean that its design was anything other than obvious or that it involved an inventive step beyond that involved in the prior design.