An optional feature of a crimping machine, namely a ‘stop’, was incorporated as an essential feature in an amendment made after acceptance of the patent specification. The question arose whether the amendment was a disclaimer for the purposes of section 31(1) or a new claim.
Held: The amendment was a disclaimer. (Lord Denning) ‘In view of those cases and others, I am clearly of the opinion that a ‘disclaimer’ takes place whenever the patentee reduces the ambit of his monopoly: for he thereby reduces his previous claim in its fullest scope and limits it to a narrower scope. This renunciation need not, however, be done in express terms. It is sufficient if it is done implicitly: and this is what I think happened in this case. The patent here is not for a single new device. It is for a combination of old devices. But the combination of these, so it is said, is new and it produces new and useful results. If so, it is patentable and anyone who takes all the essential features of the combination is an infringer. The original specification, however, is framed so widely that a ‘stop’ is not an essential feature of the combination. It includes both crimping tools without stops and crimping tools with stops. If the patent, as originally claimed, were good, it would give the patentee a monopoly in this way: if anyone produced a similar crimping tool which contained all the essential elements of the combination, he would be an infringer. Even though it does not include a ‘stop’, it would be an infringement; for a ‘stop’ is not an essential feature of the combination. Now the patentee desires to amend by making the ‘stop’ an essential feature. By doing so he reduces the ambit of his monopoly for the simple reason that, once he makes the ‘stop’ an essential feature, he can only complain of crimping tools with stops. He cannot complain of crimping tools without stops. If, after the amendment, anyone should make a crimping tool without a stop, he would not be an infringer, because he would not have taken all the essential features. In the result therefore the patentee by his amendment disclaims all crimping tools without stops and limits his claim to crimping tools with stops. That is, I think, a ‘disclaimer’ within the Act. Putting it in specialist language, once you add another essential feature to the combination, you produce a subcombination; and amendment so as to limit the scope of the specification to a subcombination which was within the original claims is disclaimer. See Baker Perkins Ltd’s application [1958] RPC 267 at 276 by Lloyd-Jacob J, approving the judgment of the Assistant Controller.’
Judges:
Denning L
Citations:
[1962] RPC 75
Statutes:
Jurisdiction:
England and Wales
Cited by:
Cited – Celltech Chiroscience Ltd v Medimmune Inc CA 17-Jul-2003
Patents had been granted in the US for human antibodies, and licences issued to the respondent who developed another product themselves. The claimants asserted infringement under the US doctrine of equivalence under which a product or process which . .
Lists of cited by and citing cases may be incomplete.
Intellectual Property
Updated: 29 April 2022; Ref: scu.184691