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 the alleged infringer had found that an arcuate rod of vulcanised rubber with slits would do just as well.
Held: The court set out the Protocol test for obviousness in a challenge to a patent.
Hoffmann J said: ‘The proper approach to the interpretation of patents registered under the Patents Act 1949 was explained by Lord Diplock in Catnic Components Ltd v Hill and Smith Ltd . The language should be given a ‘purposive’ and not necessarily a literal construction. If the issue was whether a feature embodied in an alleged infringement which fell outside the primary, literal or acontextual meaning of a descriptive word or phrase in the claim (‘a variant’) was nevertheless within its language as properly interpreted, the court should ask itself the following three questions: ‘(1) Does the variant have a material effect upon the way the invention works? If yes, the variant is outside the claim. If no- (2) Would this (i.e. that the variant had no material effect) have been obvious at the date of the publication of the patent to a reader skilled in the art. If no, the variant is outside the claim. If yes – (3) Would the reader skilled in the art nevertheless have understood from the language of the claim that the patentee intended that strict compliance with the primary meaning was an essential requirement of the invention. If yes, the variant is outside the claim.
On the other hand, a negative answer to the last question would lead to the conclusion that the patentee was intending the word or phrase to have not a literal but a figurative meaning (the figure being a form of synecdoche or metonymy) denoting a class of things which included the variant and the literal meaning, the latter meaning, the latter being perhaps the most perfect, best-known or striking example of the class.’ The first two questions involved considerations of fact, but the last was a question of construction.


Hoffmann J


[1990] FSR 181, [1989] RPC 69


Patents Act 1949


England and Wales


ExplainedCatnic Components Ltd and Another v Hill and Smith Ltd HL 1982
The plaintiffs had been established as market leaders with their patented construction, had ample production capacity and stocks, but had never granted any licence under their patent. The patent was for a novel type of galvanised steel lintel, which . .
CitedWindsurfing International Inc v Tabur Marine (Great Britain) Limited CA 1985
Testing Validity of a Patent
A patent was challenged where the windsurf board had been shown as a primitive prototype to have been built and used in public by a twelve year old boy. The court set out the four steps required to be taken when ascertaining the validity of a . .

Cited by:

CitedRocky Mountain Traders Limited and Hewlett Packard Gmbh; Westcoast Limited and Fellowes Manufacturing (UK) Limited CA 20-Dec-2000
The claimant appealed an order finding its patents for mechanisms for labelling CDs invalid for obviousness.
Held: the judge had applied the correct tests for obviousness, and the view taken by the judge of the expert evidence was not open to . .
CitedKirin-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 . .
CitedW L Gore and Associates Gmbh v Geox Spa PatC 7-Oct-2008
The claimants sought a declaration of non-infringement of four patents relating to waterproof fabrics for shoes.
Held: The patents could not be set as invalid for obviousness. . .
CitedSymbian Ltd v Comptroller General of Patents CA 8-Oct-2008
No Pattern Established to Patent Computer Systems
The Comptroller appealed against the decision in Chancery to grant a patent to the clamant for an invention which the comptroller said should have been excluded from protection under section 1(2) as a computer program. It was argued that the UK was . .
CitedOcclutech Gmbh v Aga Medical Corp ChD 31-Jul-2009
The claimants sought a declaration of non-infringement of patents involving medial devices. The patent owner claimed infringement and the claimant also sought revocation of the patent for obviousness.
Held: The device did not infringe the . .
ReformulatedEli Lilly v Actavis UK Ltd and Others SC 12-Jul-2017
The issue raised on this appeal and cross-appeal is whether three products manufactured by Actavis would infringe a patent whose proprietor is Lilly, namely European Patent (UK) No 1 313 508, and its corresponding designations in France, Italy and . .
CitedWheatley, Bortec Limited v Drillsafe Limited, Force Group Services Plc, Foster, Foster, Carter, Davies CA 25-Jul-2000
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 . .
Lists of cited by and citing cases may be incomplete.

Intellectual Property

Updated: 11 May 2022; Ref: scu.188259