Section 60(5)(b) of the Patents Act 1977 provides a defence to infringement where use which would otherwise amount to infringement (i.e. falls within the scope of the claims) is done for experimental purposes relating to the subject matter of the invention.

In the recent case of Meter-Tech LLC and Vanclare SE LLC v British Gas Trading Limited [2016] EWHC 2278 (Pat), British Gas were accused of infringing Meter-Tech’s patent (Meter-Tech were the exclusive licensee) for a smart meter and in turn sought revocation of the patent. The alleged infringement was said to affect a £600 million contract for 16 million smart meters with the value of the claim in excess of £10 million.

British Gas contended that all of the past and current acts of alleged infringement were entitled to the experimental use defence of Section 60(5)(b).

Some of the alleged infringements were denoted as trials but were on a significant scale. British Gas had ordered around 1000 meters considered to fall within the scope of the patent and had installed 120 of the meters in customers premises. The court accepted that the meters had been installed as a trial to assess their suitability. There was evidence to show that this was one of a number of trials carried out using different metering systems. However, it did not necessarily follow that such trial was to be considered for “experimental purposes”.

It was specifically noted that the trial was of a system designed and built by a third party and there was no evidence to indicate that British Gas was undertaking any kind of research directed to improving the design of the metering system in question.

The case law says that a trial having multiple purposes may still benefit from the defence, depending on the overall balance of its purpose. A trial aimed at determining whether an invention works or at finding information to advance the design is more likely to benefit from the defence. A trial aimed at demonstrating a product works for regulatory purposes or determining whether a product is commercially viable is less likely.

The trial of the 120 meters by British Gas was accepted as being a pilot study designed to test acceptability of the meters on a live system. Given that mixed purposes of such a trial, including a commercial element, may still be experimental, the judge decided that the trial of the meters qualified as use for experimental purposes, rather than just a demonstration of the suitability of the meters in question. It was also accepted that the trial was of a system falling within the scope of the claims (i.e. would otherwise be an infringement of the patent).

However, the judge then went on to consider whether or not the use related to the subject matter of the invention. Here British Gas were not successful.

The judge decided that the trial of the meters was not intended to find out anything related to the subject matter of the invention and so not entitled to the defence.

The factors supporting this conclusion were that the trial of the meters was a test of suitability of “a ready-made system” and not “genuine research relating to the development of metering”. The judge noted that the trial was carried out by a customer of a ready made off the shelf system. British Gas could not provide any evidence to show communications with the manufacturers of the meters to discuss improvements to the metering system. The trial was merely a test of the suitability of the purchased meters and metering system for the purposes of British Gas rather than research relating to the development of improvements in metering. The use by British Gas was not directed at improving the underlying system but was concerned primarily with customer satisfaction surrounding installation time and usability.

Therefore the experimental use defence failed. The court also found that an ongoing implementation on a far larger scale was also experimental but again did not relate to the subject matter of the invention.

Fortunately for British Gas, the patent was found to lack inventive step. The claims related to adoption and uses of a number which uniquely identifies a specific meter for directing a pre-payment to the correct meter in a wireless system. This was found to be obvious over various prior art documents and the evidence of expert witnesses.

This decision illustrates that the experimental use defence cannot be regarded as a broad safety blanket for trials or beta testing and that the aims of such trails must be considered in detail.

While the claims of the patent were found to be obvious over the prior art, the judge also considered obviousness over the common general knowledge. Although it was accepted that the technical contribution of the patent was only a single step beyond the common general knowledge, the judge refused to find that the claims were obvious over the common general knowledge on the grounds that to make such a finding would be unfair when the claimant had not known that it faced this argument. He explicitly stated, however, that he was not finding that the claims were not obvious over the common general knowledge.

This part of the decision demonstrates the difficulties involved in pleading a case on obviousness over common general knowledge alone in sufficient detail to enable a finding of invalidity to be made, where the pleading must often be drafted before all possible claim constructions have been considered.