Pozzoli SPA v BDMO SA & Ors

Patent claims are construed purposively, in the context of the specification, but construction cannot extend the monopoly beyond the language of the claims. Questions concerning immaterial variants are part of construction and do not create a general doctrine of equivalents.

For obviousness, the court identifies the inventive concept, the common general knowledge, the differences from the prior art, and whether those differences would have been obvious. A technical prejudice must be general and genuinely overcome; commercial disadvantages or a continuing risk do not establish an inventive step.

The claimant alleged that the defendants’ Double Push Tray infringed European Patent (UK) 0 676 763, concerning containers for multiple discs. The defendants denied infringement and challenged the patent’s validity for obviousness, lack of novelty and added matter.

The principal issues were the construction of “region”, “axially retained” and related expressions in claim 1, whether the product fell within the claim, and whether the claimed arrangement was obvious in light of common general knowledge and cited prior art.

1. Construction. The claim had to be construed purposively and in context. The court adopted the principles summarised in Technip France SA’s Patent [2004] RPC 46, as modified in Halliburton Energy Services Inc v Smith International (North Sea) Ltd [2006] RPC 2. Purposive construction did not permit the claim to be extended after construction to cover variants outside its scope.

2. “Region” meant the moulded depression in the tray, rather than the precise three-dimensional position occupied by a disc. “Axially retained” meant retained about the disc’s axis of rotation, by a central coupling device. The claim therefore required different-level regions, central retention and axially offset discs.

3. Infringement. The Double Push Tray did not infringe. Its tray was flat and did not contain regions at different levels. Its discs were retained at their peripheries rather than by central coupling devices. Even on the claimant’s broader construction, the discs required lateral or rotational disengagement before removal.

4. Obviousness. Applying the four-stage approach in Windsurfing International Inc v Tabor Marine (Great Britain) Ltd [1985] RPC 59, the inventive concept was a way of reducing the height of a two-disc container without exposing the discs to serious damage. The relevant difference from the state of the art was partial overlap, offset axes and physical separation. Overlapping discs and separating them physically would have been obvious to a competent designer.

5. The alleged technical prejudice against overlapping discs was not established. Any disadvantages were capable of being traded off against other considerations and were not a general technical prejudice. In any event, the risk of scratching remained the same kind of problem after the invention, so no false prejudice had been overcome.

6. The patent was invalid for obviousness in light of common general knowledge. Alternatively, if valid, it was not infringed. The novelty and added-matter arguments did not arise.