Icescape Ltd v Ice-World International BV & Anor

Priority requires the skilled person to derive the claimed subject matter directly and unambiguously from the priority document, using common general knowledge to understand the disclosure but not to add information which the document does not teach. A document that merely prompts the skilled person to use the disclosed invention in a further way does not support priority for that use.

Patent claims must be construed purposively in context, but deliberate limitations cannot be ignored. A coupling member required by the claim must perform the function stated in the claim; it cannot be replaced by an implicit requirement that the system merely be connected and leak-free. A threats defence under section 70(2A) of the Patents Act 1977 requires proof of the relevant state of knowledge or suspicion.

The claimant sought relief arising from alleged threats of patent infringement concerning a patent for a cooling member used in a mobile ice rink. The defendants contended that the threats were justified and relied on section 70(2A) of the Patents Act 1977. The claimant also sought a declaration of non-infringement and revocation of the patent, while the defendants counterclaimed for infringement.

The patent was invalid for prior use unless it was entitled to the priority date claimed from an earlier priority document. The court therefore considered priority, construction and infringement, and the defendants’ statutory defence to the threats claim.

1. Priority. The court applied the direct-and-unambiguous disclosure test. The skilled person uses common general knowledge to interpret the priority document, but the document does not thereby disclose all common general knowledge. The relevant question is whether the priority document gives essentially the same information as the claim and enables the skilled person to perform the invention.
2. The priority document disclosed a mobile heat exchanger with pivoting coupling elements and multiple assemblies. It did not disclose the claimed arrangement of at least two elements placed alongside one another, with their feed and discharge manifolds coupled in the claimed fluid-tight manner. The disclosure might prompt the skilled person to make the claimed arrangement, but that was an addition to the disclosure. The patent therefore lacked the claimed priority and was invalid because of prior use.
3. Construction and infringement. The claims were construed purposively and as a whole. Feature E required a coupling member joining the respective feed and discharge manifolds of adjacent elements so that the manifolds extended in series. It was impermissible to replace that limitation with a general requirement that the pipework be connected so that coolant could circulate without leakage. The claimant’s device lacked features D and E, so the infringement claim failed and the declaration of non-infringement succeeded.
4. Threats. Section 70(2A) requires the defendant to prove both that the threatened acts constituted infringement and that, when making the threats, the relevant person did not know and had no reason to suspect the patent’s invalidity. The defendants led no satisfactory evidence on the state of mind of those responsible for the threats. The court was slow to infer that state of mind in their favour. The defence therefore failed.
5. The action succeeded in every respect. The patent was revoked, the declaration of non-infringement was granted, and the defendants had no defence under section 70(2A).

First-instance decision of the High Court (Patents Court). No prior appellate decision is stated in the judgment.