Amersham Pharmacia Biotech AB v Amicon Ltd & Ors

Patent claims must be construed as part of the specification, taking account of both fair protection for the patentee and reasonable certainty for third parties. The Protocol on the Interpretation of Article 69 does not permit the court to disregard a claim integer merely because it appears unnecessary to the inventive concept. Nor does it create a general doctrine of infringement by equivalent effect where a different mechanism produces the same result. A claim requiring means for moving a probe into and out of a chromatography column did not cover an apparatus with a stationary probe and a movable sleeve. Obviousness must be assessed without hindsight. Although the skilled person is deemed to know pleaded prior art, a document from a distant field will not readily be combined with other prior art without a reason to do so.

Amersham appealed from the judgment of Laddie J dated 26 October 2000, which held that the respondents’ Isopak chromatography apparatus did not infringe the Chromaflow patent, GB 2258415. The respondents accepted that the alleged acts had occurred but maintained that the patent was not infringed. They also filed a respondents’ notice alleging invalidity if infringement were established.

The principal issue was whether claim 1, properly construed under section 125 of the Patents Act 1977 and the Protocol on the Interpretation of Article 69, covered an apparatus in which the probe remained stationary while a sleeve opened and closed the relevant passageway. The court also considered added matter and obviousness.

The appeal was dismissed. The patent was held not to be infringed, and the validity attack was rejected.

1. Construction. Under section 125 of the Patents Act 1977 and the Protocol, the court’s task is one of interpretation. The claim must be read through the eyes of the skilled person in the context of the specification as a whole. The court must seek a position combining fair protection for the patentee with reasonable certainty for third parties.
2. Claim 1. Integer (15) required means for moving the rod relative to the conduit so as to move the probe into and out of the housing. That feature was not an inessential integer. The specification showed that movement of the probe was intended to address hardened spent media. The Isopak had a stationary probe and a movable sleeve. It therefore lacked the required feature and was materially different.
3. Equivalent effect. The fact that the Isopak could produce an equivalent result by a different mechanism did not bring it within the claim. The Protocol did not introduce a general doctrine of infringement by equivalent effect, and the claim’s words could not simply be disregarded.
4. Validity. The added-matter argument failed on the construction adopted. The obviousness attack based on Farmitalia and Schaaf also failed. Schaaf concerned a very old patent from a distant technological field, and combining it with Farmitalia depended on hindsight. The appeal was dismissed with costs, a certificate of validity was granted, and permission to appeal to the House of Lords was refused.

• Court of Appeal (Civil Division): dismissed the appeal from Laddie J’s judgment dated 26 October 2000. The court held that the Isopak apparatus did not infringe and granted a certificate of validity.