Developments to the law regarding prior use – Claydon v Mzuri and Emson v Hozelock

Hoes, hose, and what the public knows


Sam Harvey and Andy Bowler wrote an article for IP Magazine, analysing and comparing the Claydon v Mzuri and Emson v Hozelock rulings, where the judges decided on two different outcomes on what constituted a prior use.

The Emson v Hozelock case is about extendable garden hoses. The judgment makes a distinction between: information that is made accessible to the public, but is nevertheless not accessed by the public; and information that no member of the public could in fact have accessed.

This distinction was followed in the ruling for the second case, Claydon v Mzuri, related to mechanical seed drill to be pulled behind a tractor: a larger invention which, unlike gardening tools, electronic or pharmaceutical inventions, can’t be tested inside a building under strict obligations of confidentiality.

The judgment result, however was different, because the evidence in Claydon didn’t demonstrate that the inventor would in fact have concealed his (large) patentable prototype invention had an observer been present.

Sam and Andy conclude that inventors shouldn’t rely only on an assertion that they would have hidden the invention without evidence that this would have been practical and possible.

You can read the full article on the IP Magazine website.

Andrew Bowler


Sam Harvey


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