Posted on 2/11/2018

Expansion of scope for patent infringement confirmed

The Court of Appeal’s decision in Icescape v Ice-World confirms the significance of the changes to patent infringement law.

As reported in July 2017 (link), the Supreme Court, the country’s highest court, handed down a judgment on patent infringement that delivered the most significant change in the law of patent infringement in the last decade, and probably the biggest change in the career of most patent attorneys.

There was speculation at the time about how wide ranging the change would be, and a recent decision (Icescape v Ice-World in the Court of Appeal) delivered by Lord Kitchin has confirmed that the changes are significant, with the (now Supreme Court) judge explaining that in his view the new test for infringement is “markedly different” from before.


The most important aspect of the 2017 decision (Actavis v Eli Lilly) meant that patents might in future be found to be infringed by actions that would not previously have been considered infringing.

In brief, in the Actavis case, Eli Lilly discovered that when combined with vitamin B12, the side effects of a particular drug (pemetrexed) were largely avoided.  Eli Lilly therefore obtained a patent claiming the combination of vitamin B12 and the specific compound of pemetrexed, pemetrexed disodium.

Actavis sought to produce a competing product using vitamin B12 with a different pemetrexed compound, specifically (a) pemetrexed diacid, (b) pemetrexed ditromethamine, or (c) pemetrexed dipotassium.

These compounds all contain the same active ingredient, pemetrexed, and work in exactly the same way, but they lack the “disodium” ion, using chemically equivalent, but different, ions in its place.

The Supreme Court decided that even though under normal interpretation, there would be no infringement, because the allegedly infringing “variant” fell outside the meaning of the words of the claim, the variant nonetheless infringed because it varied from the invention in a way which was immaterial.

In justifying that the difference was immaterial, the Court determined that it was obvious that the variant achieved substantially the same result in substantially the same way and that the reader of the patent would not conclude that the patentee intended that strict compliance with the literal meaning of the relevant claim (i.e. the requirement for the disodium ion) was an essential requirement of the invention.

Whilst this change was noted as a significant departure from the status quo, for many practitioners outside the field of Chemistry, it was unclear how significant an effect it would have.  This is in particular because when dealing with mechanical/electrical inventions it is not uncommon in a claim to define a feature by its function and therefore effectively encompass all equivalents to a feature.  For example, we might claim a “fixing means” rather than a screw.

The Judgement in Icescape v Ice-World

In Icescape v Ice-World, the invention at issue was not chemical, but mechanical; a system for cooling mobile ice rinks.  Although the patent owned by Ice-World was held invalid, the judge ruled that, if valid, it would have been infringed by Icescape, despite the fact that it would not have been held to infringe under the approach taken before last year’s Supreme Court decision.

In particular, in this case, the key inventive feature; the “inventive core” of the patent in the words of Lord Kitchin, was considered to be the provision of a joint member which allowed the cooling pipes of the mobile ice rink to be folded up for transportation, without disassembly.

However, the main patent claim, which should define the scope of protection was fairly long and quite specific as to the structure of the cooling member of the mobile ice rink, that included the flexible joints.

In particular the claim included terminology that required two “cooling elements” made up of a feed manifold and a discharge manifold with pipes connected in between, and required, in effect, that the two elements were coupled in series with each other (wherein the feed and discharge manifolds of the two elements are provided with a coupling member (47, 48) to make a fluid-tight connection between the respective feed and discharge manifolds of the first and the second element).

These features (as well as the feature of the “inventive core”) were present in the “characterising” part of the patent claim – which is the part of the claim which is considered to distinguish the invention from the most relevant example of known technology considered when the application was examined; the “closest prior art”.

In consequence, on initial reading, it could well be considered that all of the features in the characterising portion of the claim combine to form the “inventive core”.

In the opinion of the judges, however, these other features of the invention were not part of the inventive core; they were, in the court’s view, features of conventional systems.

This conclusion meant that Icescape’s “variant” of the invention, which in effect had the two cooling elements coupled in parallel rather than in series, but included the joint member that allowed folding, was considered to achieve substantially the same result in substantially the same way as the invention.

The judges also took the view that it would be obvious to the person skilled in the art, reading the patent and knowing that the variant achieves substantially the same result as the invention, that it does so in substantially the same way as the invention.

And, the judges decided that the skilled reader of the patent would not have concluded that Ice-World intended that strict compliance with the literal meaning of the claim.

Having reached these conclusions, it was decided that the Icescape product would fall within the scope of protection.  Fortunately, for Icescape, however, the patent was held invalid, and in fact Ice-World were guilty of making groundless threats of infringement.


This decision may be welcomed by patent owners as it confirms that the scope of protection available in the UK can cover competing products that use the same inventive concept, even if they do not fall within the words used to define the invention.  Arguably, it may make patent law easier for non-experts, who might find it easier to identify what the inventive core of a patent is than to determine the scope of a patent claim.

On the other hand, the decision certainly confirms that it is it more difficult to ascertain the scope of protection based only on the patent at issue, which is bound to reduce legal certainty and/or increase the time and cost to provide an opinion on infringement.

It is notable that in both this case and Actavis v Eli Lilly, the judges found it straightforward to identify the “inventive core”.  Certainly there are patents where the nature of the inventive concept is much more difficult to ascertain.  Especially when considering patent applications that have not yet been granted, there may appear to be many “cores” or potentially inventive cores, and the part which seems inventive could change according to the “prior art” located.


We would reiterate our advice to revisit any infringement opinions given before the Actavis v Eli Lilly decision in July 2017 (and perhaps opinions produced shortly afterwards), as it is clear that that decision has wide application regardless of the technology concerned.

In particular, most opinions prior to the Actavis v Eli Lilly decision will only comment on infringement under a “purposive construction”, but now, having decided on non-infringement under a purposive construction, it is necessary to consider whether the patent might be infringed by “equivalence”.

This will be relevant whether you are concerned about a competitor infringing your patent, or concerned about infringing your competitor’s patent.

If you have any questions, do not hesitate to contact one of our patent attorneys.

Wilson Gunn