28 IIC 114 (1997) UNITED KINGDOM Patents Act 1977, Secs. 3, 60, 125 ; European Patent Convention, Protocol on the Interpretation of Art. 69 - "Kastner" 1. A patent specification must be construed as a whole and the claims must be given a "purposive" construction, as set out in Catnic Components Limited v. Hill & Smith Limited [1982] RPC 183. 2. The court's task is to ascertain whether the skilled man would understand that strict compliance with a particular descriptive word or phrase appearing in a claim was intended by the patentee to be an essential requirement of the invention. Decision of the Court of Appeal June 16, 1995 Kastner v. Rizla Limited From the Facts : The specification of the patent in suit stated that the invention related to apparatus for interleaving paper strips and in particular to the interleaving of flat cigarette papers which were packaged and sold in small booklets. The stated object of the invention was to provide a process and apparatus for holding and interleaving continuously moving endless strips of paper and cutting the interleaved strips into packets of desired lengths, and which avoid the problems and difficulties inherent in the prior art devices and provide a high rate of productivity with a minimum of waste. The specification stated that the invention could be considered to consist of two major assemblies, the first being that which interleaved and the second that which severed the strips into packs. The way that the cut strands of interleaved paper were stacked was not mentioned as being a problem associated with known machines nor did it form part of the stated invention although appropriate means were included in the description of the specific embodiment. The proprietor of the patent brought proceedings in the Patents County Court for infringement in respect of a machine of similar type to that described in the specific embodiment in the patent but with two differences. First the knife was a crescent-shaped rotary blade instead of a reciprocating knife as described in the patent. Second, the cut stacks were moved by a pusher plate operating with an up and over action rather than, as described in the patent, a pusher plate which moved with the knife in both directions. The defendants counterclaimed that the patent was invalid for obviousness having regard to a German patent of 1926 referred to as "Munchen". The judge held that the patent had not been infringed and that the attack on its validity failed. The plaintiff appealed to the Court of Appeal, and the defendants contended that if their machine fell within the ambit of any claim of the patent then the patent was invalid as it was obvious in view of the disclosure in Munchen.
From the Opinion : Aldous L.J. : Two issues are raised on this appeal. 1. Does the machine alleged to infringe fall within the ambit of the patent? I will refer to that as the infringement issue. 2. If there be infringement, is the patent invalid as being obvious having regard to the disclosure in Munchen? Infringement As this patent was filed in 1980 it is subject to the Patents Act 1977. For the first time that Act defined infringement. Section 60(1) of that Act states that : "a person infringes a patent for an invention if, but only if, while the patent is in force, he does any of the following acts in the United Kingdom in relation to the invention without the consent of the proprietor of the patent." The scope of the invention has to be determined in accordance with section 125 of the Act which requires that the claims must be interpreted according to the Protocol on the Interpretation of Article 69 of the EPC. It is in this form. Article 69 shall 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 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. After the 1977 Act came into force, the ambit of the invention claimed was ascertained by the courts using "purposive" construction as explained by Lord Diplock in Catnic Components Ltd. v. Hill & Smith Ltd. [1982] R.P.C. 183 at 243 [12 IIC 699 (1981) - Catnic] and subsequently using the guidance given by Hoffmann J. in Improver Corp. v. Remington Consumer Products Ltd. [1990] F.S.R. 181 at 189 [21 IIC 860 (1990) - Epilady United Kingdom II]. However in PLG Research v. Ardon International Ltd. [1995] R.P.C. 287 at 309 the Court of Appeal suggested that that approach to construction might not accord with the Protocol, but they did not feel it was necessary to come to any concluded view on the matter. Having regard to the view expressed in PLG Research, I had in Assidoman Multipack Ltd. v. Mead Corporation [1995] R.P.C. 321, to reconsider whether what can be called the Catnic approach was the correct way to ascertain what was the appropriate ambit of a patent claim. In Assidoman, I looked at the historical background to the way that inventions had been described and claimed in patents and considered the Protocol. I concluded that the Catnic approach was that which the 1977 Act contemplated as correct and, in any case, that it was binding until the House of Lords said to the contrary.
I also believe that this Court is bound to apply the Catnic test when considering the ambit of a patent claim under the 1977 Act. I am encouraged in that view by the observations of Jacob J. in Beloit Technologies Inc. v. Valmet Paper Machinery Inc. 28 April 1995 (not yet reported). A patent specification must be construed as a whole and the claims must be given a "purposive" construction. However I believe that it is useful to recall the well known passage of Lord Diplock in Catnic and the guidance given by Hoffmann J. in the Improver case. Lord Diplock said in Catnic : My Lords a patent specification is a unilateral statement by the patentee, in words of his own choosing, addressed to those likely to have a practical interest in the subject matter of his invention (i.e. "skilled in the art") by which he informs them what he claims to be the essential features of the new product or process for which the letters patent grant him a monopoly. It is those novel features only that he claims to be essential that constitute the so-called "pith and marrow" of the claim. A patent specification should be given a purposive construction rather than a purely literal one derived from applying to it the kind of meticulous verbal analysis in which lawyers are too often tempted by their training to indulge. The question in each case is : whether persons with practical knowledge and experience of the kind of work in which the invention was intended to be used, would understand strict compliance with a particular descriptive word or phrase appearing in a claim was intended by the patentee to be an essential requirement of the invention so that any variant would fall outside the monopoly claimed, even though it could have no material effect upon the way the invention worked. Hoffmann J. in the Improver case adopted the guidance given by Lord Diplock and suggested that the court should ask the following three questions, which can conveniently be referred to as the "Improver 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 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 include the variant and the literal meaning, the latter being perhaps the most perfect, best-known or striking example of the class. The Catnic test requires the court to see whether a variant is excluded from the ambit. Thus in practice the court has to have in mind the context in which the dispute arises. The court's task is to ascertain whether the skilled man would understand that strict compliance with a particular descriptive word or phrase appearing in a claim was intended by the patentee to be an essential requirement of the invention so that any variant would fall outside the monopoly claimed, even though it could have no material effect upon the way the invention worked.
I do not believe that the difference between the wording of the patent and the respondents' machine in this respect is such as to avoid infringement. Thus the respondents' machine varies from the claim. The variant can I believe be fairly described as the use of a pusher plate which does not operate with the knife according to the equal velocity principle. I must therefore decide whether the skilled man would believe that such a variant was excluded from the claim and in so doing I believe it appropriate to use the Improver questions. 1. Does the variant have a material effect upon the way the invention works? In the present case, I believe that the invention is broadly described in the title of the patent - "Apparatus for paper interleaving and severing". That is amplified by the opening words of Claim 1 : "Apparatus for folding and interleaving continuous moving strips of paper and cutting the interleaved strips into packets of interleaved paper sheets comprising ". If that be the invention then there is no evidence that the variant has any material effect on the way that it works. 2. Would the fact that the variant had no material effect have been obvious at the date of publication of the patent to a reader skilled in the art? I have no doubt that it would be evident to a skilled man to use a mechanically equivalent pusher plate arrangement once a decision had been made to use a rotary knife. 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? I believe that the skilled reader would have understood that the method of operation of the pusher plate was not an essential requirement of the invention. The answers to the Improver questions indicate that the patent has been infringed by the respondents' machine. Is that result consistent with the approach indicated in the Protocol? It cannot be doubted that the conclusion reached would be seen by the patentee to provide a fair protection for the patentee. Further I believe that the result does mean that the ambit of the claim could have been ascertained with a reasonable degree of certainty. The skilled man who read the specification could have been in no doubt that the invention lay in the interleaving and severing assemblies which enabled the disadvantages of the prior art to be overcome. Thus he would have realised that the mode of operation of the pusher plate was not envisaged as being essential to the operation of the invention and he would not be surprised that the court would conclude that the invention claimed had been taken by a machine which incorporated the interleaving and severing assemblies, but which had a pusher plate which had the effect required by the claim and was mechanically equivalent. Validity A patent will be held invalid under section 72(1) (a) of the Patents Act 1977 if it does not involve an inventive step. Section 3 of the Act states : "An invention shall be taken to involve an inventive step if it is not obvious to a person skilled in the art, having regard to any matter which forms part of the state of the art by virtue only of section 2(2) above (disregarding 2(3) above)".
The most appropriate approach to ascertaining whether an invention is obvious is that set out by Oliver L.J. in Windsurfing International Inc. v. Tabur Marine (Great Britain) Ltd. [1985] R.P.C. 59 at 73. There are, we think, four steps which require to be taken in answering the jury question. The first is to identify the inventive concept embodied in the patent in suit. Thereafter, the court has to assume the mantle of the normally skilled but unimaginative addressee in the art at the priority date and to impute to him what was, at that date, common general knowledge in the art in question. The third step is to identify what, if any, differences exist between the matter cited as being "known or used" and the alleged invention. Finally, the court has to ask itself whether, viewed without any knowledge of the alleged invention, those differences constitute steps which would have been obvious to the skilled man or whether they require any degree of invention. I take the invention as consisting of the interleaving and severing assemblies as claimed with a pusher plate which pushes the severed packets laterally. There is no dispute as to the state of the art at the priority date. At that date the star wheel machines referred to in the opening paragraphs of the specification were commonly used. However the notional skilled man would be familiar both with rotary and reciprocating cutting techniques and have a knowledge of normal engineering techniques. Munchen discloses a machine for producing folded and interleaved sheets of paper from rolls of paper, particularly cigarette paper. Paper from four supply rolls are pulled over four guide rolls and then through one set of folding combs. From there the interleaved strips pass through a cutter device which operates using the equal velocity principle. Disposed downstream of the cutter are a pair of oppositely directed teeth (e, f) which move in sequence so that they first move towards each other, then sideways, then apart and then return to their original position so as to restart the operation. The function of the teeth is to hold the interleaved paper and then move it sideways one step so that a following strip of paper will be interleaved. The process is repeated until a stack is accumulated at which stage a gripper device picks up the stack and deposits it onto a conveyor. That operation is accurately summarised in the claims of Munchen. Claim 1 sets out the general construction of the machine. Claim 2 adds cutting by the equal velocity principle, claim 3 describes the interleaving operation using the teeth and claim 4 the gripper which removes the stacks. 1. A machine for producing alternately folded and interleaved sheets of paper in which a plurality of paper strips which are drawn from supply rolls are passed in a position of being respectively displaced by half their width, between two comb-like shaping tools which engage one into the other with their teeth and in the gaps of which the strips are respectively subjected to V-shaped folding, with alternately upwardly and downwardly directed fold edges, characterised in that the paper strip folded in that way is fed by means of feed rollers (c) to a reciprocating cutter device (d) which allows the end of the strip (5) to pass between it, over the one lateral edge portion of the strip portion which has been previously cut off and which is held by two teeth (e, f), as far as the length of the said strip portion, and then automatically cuts it off. 2. A machine according to claim 1 characterised by a cutter device, which returns after each strip portion has been cut off and then, accompanying the strip at speed of movement thereof,
moves forward again therewith until the end thereof has been pushed over said previously cutoff portion, as far as the length thereof, whereupon it automatically cuts off a portion of the same length. 3. A machine according to claims 1 und 2 characterised by a device which provides for collecting and interleaving of the cut off portions of the strip and which accom modates said strip portions by means of teeth (e, f) therebetween and which for that purpose always approaches the blade, moves rapidly forward after receiving a fresh portion and then displaces the portions which have been accommodated sideways to such an extent that the next following end of the strip can be pushed with one of its side portions over the adjacent side part of each portion in such a way that both strip portions are interleaved with their lateral ends. 4. A machine according to claims 1 to 3 characterised by a gripper (i) which with its carriage is always held in each case in its rest position, by means of levers and cam disc, until the collecting device (e, f) has been received and interleaved a corresponding number of portions of the strip (5), whereupon it is rapidly advanced by said actuating means, picks up the bunch of portions from the collecting plate member (g) and, immediately returning therewith, deposits same on a conveyor belt (j). I accept that claim 1 of the patent does not limit the invention to providing any particular number of interleaved strips to form a packet, but the man skilled in the art would have been surprised to be told that four strips formed a packet. However I am prepared to assume that four strips would be understood to be a packet Even so, I have been unable to find any pusher plate disclosed in Munchen. Would it be obvious to alter Munchen so as to provide a pusher plate? Clearly not. The fingers of Munchen are essential to carry out the interleaving and could not be replaced by a pusher plate. Further there is no evidence to suggest that such a change would have been obvious at the priority date nor how it would have been achieved. Munchen was published in 1926 and although it would be read by the skilled man with interest it would not be a starting point from which to design a machine to overcome the problems of the star wheel machines Published in [1995] 20 R.P.C. 585.