The Nestec case addressed for the first time in England the issue which has become known as 'toxic' or 'poisonous' priority namely a claim which fails to claim priority is then held invalid as a result of the priority document having been subsequently published and thereby being deemed to form part of the state of the art for the purpose of novelty.
Nestec's patent related to a coffee extraction system. Nestec alleged that Dualit had infringed the patent by supplying coffee capsules which were compatible with Nestec’s Nespresso coffee machines. Dualit denied infringement and counterclaimed for revocation on several grounds including lack of entitlement to priority coupled with an anticipation attack based on the disclosure in a deemed intervening publication, namely that of the priority document itself. The case also raised an issue as to partial priority i.e., affording different priority dates to different parts of a patent claim.
Dualit put forward two reasons why claim 1 of the patent was not entitled to claim priority from the priority document. First, claim 1 of the patent covered several different arrangements in which the housing to receive the capsule was contained, only one of which was disclosed in the priority document. Second, claim 1 of the patent covered several different orientations of the capsule in its intermediate position relative to the extraction axis, at least two of which were not disclosed in the priority document.
The Judge held that claim 1 was not entitled to claim priority or even partial priority from the priority document for both reasons. The claim to partial priority was rejected on the basis that the arrangements or orientations which claim 1 covered were not disclosed as clearly defined alternatives.
Having held that claim 1 was not entitled to claim priority, the Judge went on to hold that the claim lacked novelty over the priority document which having been published was therefore deemed to form part of the state of the art pursuant to section 2(3) of the Patents Act 1977 (corresponding to Article 54(3) EPC - novelty-only prior art effect of post-published patent applications having an earlier priority date).
Appealed but settled.