Defending a patent infringement case before the IP Enterprise Court and Court of Appeal

Dehns acted for Freyssinet Ltd, part of the global Freyssinet group and a leading provider of civil engineering technology, when they and barrister Lindsay Lane successfully defended a patent infringement case before the IP Enterprise Court and Court of Appeal.

The patent concerned a “hybrid” cathodic protection method and an anode for use in such a system to treat corroded reinforced concrete structures.  The case was brought by the inventors who were directors of Concrete Preservation Technologies Ltd.

It was claimed that Freyssinet had infringed the patent’s apparatus claims by offering “Galvastar” anodes for sale and the method claims by allegedly offering the Galvastar anodes for use in a system referred to as “GP Guard+”.

Whilst the Galvastar anodes were part of Freyssinet’s global product range, they had not been sold in the UK and the claimants’ case regarding the method relied upon various promotional documents originating from Freyssinet.

Dehns solution

Dehns’ attorneys considered the allegations concerning the system and the anode separately.

In relation to the alleged infringement of the apparatus claims by the Galvastar anode, Dehns approach was to demonstrate that any interpretation of the claims that was broad enough to cover the Galvastar anode would render them invalid because they would not involve an inventive step compared to known anodes – a “squeeze” argument.

To do this, they identified the most relevant prior art and worked with one of the leading experts in the field to provide detailed expert evidence. This demonstrated that the only feature that the claimants were able to say was novel – the use of non-corrosive electrical connectors – was obvious at the filing date of the patent.

With regard to the method claims, it was necessary for Dehns’ attorneys to carry out a careful investigation to determine what cathodic protection systems had been offered in the UK and, in particular, to establish how a document that described an apparently infringing method had been provided to one of the claimants. They found that the document was a confidential draft that had been prepared in relation to a proposed, but abandoned, collaboration with the claimants many years earlier.

Based upon witness evidence from the individuals involved, Dehns attorneys demonstrated that the supply of this document was a one-off error by a junior member of staff and did not relate to any part of the company’s range of services. They also ensured that the expert’s evidence described how cathodic protection systems are commissioned in practice. The judge accepted that Freyssinet never intended that the document should constitute any kind of offer.

However, this left an interesting and previously untested point of law regarding “what is an offer?” In particular, whether, and to what extent, should the intention of the alleged offeror and the belief of the offeree be taken into account. Put simply, can an offer be made by mistake, as had occurred by the provision of the draft document? (UK Patent law regards putting something on the market as an offer; it does not require a legally-binding offer as defined in contract law.)

Working with the Dehns attorneys, barrister Lindsay Lane, argued that the proper test was one of commercial substance. The judge agreed with this approach, stating in his judgment that all relevant factors must be taken into account, including the perception of the offeree. (Here it was relevant that, during cross-examination by Ms Lane, the claimant who received the document had admitted that he had recognised it as a translation of a document he had seen during the earlier abortive negotiations with Freyssinet.) The judge concluded that the supply of the document was merely the provision of information, not an offer.


The outcome was therefore highly successful for Freyssinet in that they were found not to infringe any valid claim. All of the apparatus claims of the patent were found to be invalid and ordered to be revoked. The claimants were required to make a significant contribution towards Freyssinet’s legal costs.

Although the court refused permission to appeal, this was subsequently granted by the Court of Appeal. However, the claimants subsequently abandoned their appeal so the above outcome became final in November 2016. The amendment to the patent is proceeding before the IP Office.

Further details of the case may be found in the court’s judgment which is available at:

The Team

Initial advice on the case was provided by Dehns’ Senior Partner Alex Piésold​, with the case being handed over to Robert Jackson (Dehns’ lead litigation partner) when the claim was served on Freyssinet. Robert was supported by Dehns’ Associate Jennifer Brown. As noted above, Dehns instructed barrister Lindsay Lane of 8 New Square chambers and worked closely with her throughout the case.