On appeal, H&M submitted that the trial judge -- Mr Justice Sales at
The Court of Appeal, in a judgment delivered for the court by patent specialist Kitchin LJ, dismissed H&M's appeal.
* Looking first at the mediated settlement, its recitals and substantive obligations had been broadly drawn so that any reasonable person would have understood that the parties intended to compromise all the issues in dispute including the validity of the patent. By the same logic, Stretchline was prevented from pursuing an infringement claim in addition to that for breach of contract.
* The patent and the original proceedings had been founded upon the use of "the L+M sewability tester", whereas the new proceedings were based on a pin penetration test, the results of which were not readily comparable. However, there was nothing in the body of the patent to say the sewability test had to be used. The patent's claims were cast in general language and there were powerful grounds for saying that the skilled person would consider that the resistance of the tube could be measured using any conventional test.
* There was no evidence that H&M had entered the settlement agreement on the basis that the sewability test was the only test of penetration, and the parties could reasonably be taken to have intended that the release should apply to claims of the kind in issue,
This decision underlines the principle that, once something appearing to be a final and global settlement of a patent infringement claim is entered into, the courts are most reluctant to depart from the proposition that it is indeed the last word on the subject.