In a claim for infringement of a patent, where variations on a patent were to be considered, the court should look to the three tests set down in Improver (‘the Protocal questions’), and the claim should be interpreted in a purposive and contextual way. The court should ask if the variation was material, would the variation itself have been obvious, and would a skilled reader have understood that the patent claim required strict compliance with its primary meaning.
The Court explained the correct approach to construction. At page 141 I said:
’18. . . Section 125 of that Act provides that an invention shall be that specified in the claim ‘as interpreted by the description and any drawings … shall be determined accordingly.’ The extent of protection is not only important when considering whether an alleged infringement falls within the claim, but also when considering validity. A patent will be invalid if the extent of protection includes within it the prior art or something which was obvious having regard to the prior art.
Section 125(3) requires the Protocol on Interpretation of Article 69 of the EPC to be applied: ‘Article 69 should not be interpreted in the sense that the extent of the protection conferred by a European Patent is to be understood as that defined by the strict, literal meaning of the wording used in the claims, the description and drawings being employed only for the purpose of resolving an ambiguity found in the claims. Neither should it be interpreted in the sense that the claims serve only as a guideline and that the actual protection conferred may extend to what, from a consideration of the description and drawings by a person skilled in the art, the patentee has contemplated. On the contrary, it is to be interpreted as defining a position between these extremes which combines a fair protection for the patentee with a reasonable degree of certainty for third parties.’
The Protocol outlaws what can be termed strict literal and also liberal interpretation using the claims as a guideline. The correct approach is to achieve a position between those extremes ‘which combines a fair protection for the patentee with a reasonable degree of certainty for third parties.”
Aldous LJ, Sedley LJ, Mance LJ
Times 25-Jul-2000,  EWCA Civ 209,  RPC 133
England and Wales
Appeal from – Wheatley, Bortec Limited v Drillsafe Limited, Force Group Services Plc, Force Group Services Plc, Foster, Carter, Davies PatC 23-Feb-1999
Cited – Anchor Building Products Ltd v Redland Roof Tiles Ltd CA 23-Nov-1988
When looking at a patents challenge the question was whether the absence of a feature mentioned in the claim was ‘an immaterial variant which a person skilled in the trade would have regarded as being within the ambit of the language.’ . .
Cited – Brugger v Medic-Aid Ltd (No 2) ChD 1996
B alleged infringement by M of its patented nebulizer. M replied saying that the claims failed for obviousness. Features of the nebulizer were admittedly old and well known, but the claimant asserted a new mechanism which reduced the size of the . .
Cited – Improver Corporation v Remington Consumer Products Ltd ChD 1989
Protocol Tests For Onbviousness Set Out
The invention was based upon the discovery that an arcuate rod with slits, when rotated at high speed, would take the hair off the skin by means of the opening and closing of the slits. The claim was to a rod in the form of an ‘helical spring’ but . .
Cited – Kirin-Amgen Inc and others v Hoechst Marion Roussel Limited and others etc HL 21-Oct-2004
The claims arose in connection with the validity and alleged infringement of a European Patent on erythropoietin (‘EPO’).
Held: ‘Construction is objective in the sense that it is concerned with what a reasonable person to whom the utterance . .
Applied – American Home Products Corporation, Professor Roy Calne v Novartis Pharmaceuticals UK Limited, Novartis Pharma AG CA 27-Jul-2000
The invention was a second medical use for a known drug rapamycin, which was found to have an immuno-suppressive effect. The court asked whether a claim to rapamycin should be construed to include derivatives.
Held: A person skilled in the art . .
Lists of cited by and citing cases may be incomplete.
Updated: 11 May 2022; Ref: scu.90438