Court of Appeal reverses revocation of machine patent but agrees that patent was not infringed

In its judgment of 17th September, the Borgarting Court of Appeal decided the appeal in HMR Hydeq AS v Storvik AS. The case had all the ingredients of a typical modern patent case: infringement action, invalidity action and questions about equivalents. However, perhaps the most interesting of the contended issues was whether the use in one industrial plant in the United States between 1953 and the 1970s of a machine for cleaning tapping crucibles that had been manufactured (as a prototype) was publicly available – which would invalidate the patent.

The court returned a split decision on this point. The majority of four (three legal judges and one technical judge) found that when the inventors had visited the plant in 1988, the premises had been fenced off and they had entered only after special permission had been obtained. Also, the machine had been developed and used on just the one plant, and there was no indication that it had been used elsewhere. The majority found that the method had not become generally known in the aluminium industry and thus could not be said to have become publicly known.

In a dissenting opinion, one of the technical judges concluded that the machine in question had become publicly available. He reasoned that an indefinite group of persons should be understood to mean a multitude of individuals that one has no control over. He presumed that the machine had been designed by one or more individuals at the plant where it had been manufactured and used for a number of years until the plant closed down. There was no information about the number of people who had been shown the machine over the years, either before or after the plant closed. The inventors had been given access to it in 1988 and no arrangements about confidentiality had been made at that time. One of the inventors had understood how the machine worked when he saw it. The dissenting judge found that in view of a combination of the cleaning machine in the closed-down plant in the United States with another reference in the art, the invention of the patent in suit lacked inventive step.

The reasons given for the decision by the majority as well as the dissenting opinion are not entirely convincing. Whether or not the machine was known in the aluminium industry or not is probably not the test that should be applied. Rather, the test should be whether the machine had been accessible to an undefined circle of people under circumstances that would have enabled an average person skilled in the art – if he or she was among them – to learn enough to put the solution of the invention into practice. However, the judgment is final and binding.


This is an insight article whose content has not been commissioned or written by the IAM editorial team, but which has been proofed and edited to run in accordance with the IAM style guide.

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