Improver v Remington
Encyclopedia
Improver Corporation v Remington Consumer Product Limited [1990] F.S.R. 181 is a leading United Kingdom
case on patent infringement
, particularly in relation to how to establish what specifically a patent
covers.
, Lord Diplock had established the principle that patents were to be read in a "purposive" manner. The question to be answered in establishing infringement, as formulated by Lord Diplock, was a complex, multi-part enquiry.
:
These questions, which the Court of Appeal in Wheatly v Drillsafe Ltd [2001] RPC 133, 142 dubbed "the Protocol questions" have been used by English courts for the past fifteen years as a framework for deciding whether equivalents fall within the scope of the claims. On the whole, the judges appear to have been comfortable with the results, although some of the cases have exposed the limitations of the method. When speaking of the "Catnic principle" it is important to distinguish between, on the one hand, the principle of purposive construction which I have said gives effect to the requirements of the Protocol, and on the other hand, the guidelines for applying that principle to equivalents, which are encapsulated in the Protocol questions. The former is the bedrock of patent construction, universally applicable. The latter are only guidelines, more useful in some cases than in others. I am bound to say that the cases show a tendency for counsel to treat the Protocol questions as legal rules rather than guides which will in appropriate cases help to decide what the skilled man would have understood the patentee to mean.
The current position, therefore, is that the House of Lords has held that the principle of purposive construction is entirely in accordance with the Protocol to Article 69, but that the Improver questions may not represent the best approach for dealing with every infringement issue. See Kirin-Amgen v Hoechst Marion Roussel
.
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
case on patent infringement
Patent infringement
Patent infringement is the commission of a prohibited act with respect to a patented invention without permission from the patent holder. Permission may typically be granted in the form of a license. The definition of patent infringement may vary by jurisdiction, but it typically includes using or...
, particularly in relation to how to establish what specifically a patent
Patent
A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....
covers.
The Catnic Decision
The earlier case of Catnic Components Ltd. v Hill & Smith Ltd.Catnic
Catnic is a Welsh based building and construction products manufacturer which developed and patented a steel lintel.-History:Catnic was established in 1969 when Brian Robinson took his idea to entrepreneur Alfred Gooding. The company conceived, developed and pioneered the steel lintel designed for...
, Lord Diplock had established the principle that patents were to be read in a "purposive" manner. The question to be answered in establishing infringement, as formulated by Lord Diplock, was a complex, multi-part enquiry.
The Improver Questions
In the Improver case, Mr Justice Hoffmann (as he then was), on behalf of the Patents Court, reformulated the test as a series of three questions to establish whether a variant (alleged infringing article) infringes the claims of a patent. The variant will not infringe if any of the following are true:- The variant has a material effect on the way the inventionInventionAn invention is a novel composition, device, or process. An invention may be derived from a pre-existing model or idea, or it could be independently conceived, in which case it may be a radical breakthrough. In addition, there is cultural invention, which is an innovative set of useful social...
works. - The fact that the variant has no material effect on the way the invention works would not have been obvious to an expert in the field.
- That an expert in the field would have taken from the language used in the patent that strict compliance with the primary meaning was an essential requirement of the invention.
Facts & findings of the case
In the Improver case, the patent covered a depilatory device having a curved "helical spring" driven by a motor. The spring when rotated gripped hairs between its coils and plucked them from the skin. The alleged infringement replaced the spring with a rubber rod having slits in its surface. The question was whether the slitted rubber rod was "a helical spring". The judge answered the three questions as follows: (i) the change to a rubber rod had no material effect on the way the invention worked; and (ii) it would have been obvious to an expert that the rubber rod would work in the same way; but (iii) the expert would have understood from the patent that the patentee meant to confine his claim to a "helical spring", in its primary meaning and not in a wide generic sense. For this last reason, the rubber rod did not infringe.Continued relevance
These so-called "Improver questions" were relied on throughout the 1990s and early 2000s by the United Kingdom Courts, but in 2004 their continued relevance was called into question by the same judge who had formulated them, now Lord Hoffmann, in the case of Kirin-Amgen v Hoechst Marion RousselKirin-Amgen v Hoechst Marion Roussel
Kirin-Amgen, Inc. v Hoechst Marion Roussel Ltd. is a decision by the House of Lords of England and Wales. The judgment was issued on 21 October 2004 and relates to the scope to be accorded to patent claims, including the doctrine of equivalents. The case and subsequent judgment affirmed principles...
:
These questions, which the Court of Appeal in Wheatly v Drillsafe Ltd [2001] RPC 133, 142 dubbed "the Protocol questions" have been used by English courts for the past fifteen years as a framework for deciding whether equivalents fall within the scope of the claims. On the whole, the judges appear to have been comfortable with the results, although some of the cases have exposed the limitations of the method. When speaking of the "Catnic principle" it is important to distinguish between, on the one hand, the principle of purposive construction which I have said gives effect to the requirements of the Protocol, and on the other hand, the guidelines for applying that principle to equivalents, which are encapsulated in the Protocol questions. The former is the bedrock of patent construction, universally applicable. The latter are only guidelines, more useful in some cases than in others. I am bound to say that the cases show a tendency for counsel to treat the Protocol questions as legal rules rather than guides which will in appropriate cases help to decide what the skilled man would have understood the patentee to mean.
The current position, therefore, is that the House of Lords has held that the principle of purposive construction is entirely in accordance with the Protocol to Article 69, but that the Improver questions may not represent the best approach for dealing with every infringement issue. See Kirin-Amgen v Hoechst Marion Roussel
Kirin-Amgen v Hoechst Marion Roussel
Kirin-Amgen, Inc. v Hoechst Marion Roussel Ltd. is a decision by the House of Lords of England and Wales. The judgment was issued on 21 October 2004 and relates to the scope to be accorded to patent claims, including the doctrine of equivalents. The case and subsequent judgment affirmed principles...
.