The Unduly Broad Claim

by Dr. Matthias Brandi-Dohrn, Attorney at Law

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The EPC patent system is impaired by a serious defect which again and again has puzzled and annoyed opponents but which is hardly ever criticized in literature: that is that lack of clarity of the claim is no ground for invalidity in opposition. That is so much more annoying as the Enlarged Board of Appeal of the EPO has rightly emphasized that the claims play a central role under the EPC system (EPO G 2/88 - 1990 OJ EPO 93/102 = GRUR Int 1990,522 - Friction reducing additive/MOBIL OIL III). Indeed, it is the claims that decide how far the monopoly will reach. If the claims are directed to a result or a desideratum or to a function the claims are always of a critical width barring the same result even if it was achieved by different ways; and such width continues to be critical even if the claimed result has been achieved for the first time so that there is no objection as to novelty. A claim being thus unduly wide may possibly not be supported in all its extents by the description but up to now, in case law, this was only an objection under Art. 84 EPC - clarity. And clarity - in order to revert to the defect in the EPC system - is, other than disclosure under Art. 83 EPC, no ground for opposition and hence is not admitted as a ground for national nullity proceedings under Art. 138 EPC. As a result it is often impossible to adjust later too wide claims, in spite of their central role. It is this important problem which the present decision touches.

The decision T 409/91 was made in examination procedure, not in opposition procedure. Other than in opposition proceedings, in examination clarity, Art. 84 EPC, is in full reach of the judges. Thus it is all the more remarkable that the Board of Appeal decided undue width of the claim not only as a matter of clarity, Art. 84 EPC, but also as one of insufficient disclosure, Art. 83 EPC.

The invention in question deals with the well known problem that diesel fuel loses its fluidity in cold temperature. This phenomenon is due to crystallization of wax particles which block the filter of the engine. The inventors of the application EP 0 261 958 have found that the waxy crystals in diesel fuel can be made sufficiently small to pass even at low temperatures through the filter paper when an additive of a formula disclosed in the patent specification is added. The applicant describes that the necessary small size and fluidity is only obtained when a specific additive is present. The applicant did not claim the specific additive or a fuel processed with that additive but the result, that is a fuel having wax crystals smaller than 4000 nanometers.

This claim posed a first problem: "less than 4000 nanometers" covers anything down to 1 nanometer but the smallest size actually achieved was, according to the examples, 1200 nanometers. The board decided that ranges below the actually disclosed examples could not be claimed.

The applicant took care of this problem by an auxiliary set of claims which led to the more important second problem: Is an applicant allowed to claim a result - or a function if he has found and disclosed just one way, one solution to obtain the result or the function? In the actual case: is the applicant allowed to monopolize diesel fuel with small wax crystals in general if his contribution to the state of the art was a specific additive bringing about such small wax crystals. The impact of the problem is connected to the well established principle in national and European law that a patent which claims a physical entity or a compound per se, confers absolute protection also if used or if produced in a different way (see EPO G 002/88 - 1990 OJ EPO 93/104 - friction reducing additive/MOBIL OIL and in Germany BGH IIC, 3/386 = BGHZ 58, 280 = GRUR 72, 541 - Imidazoline). If in future someone solved the problem of sufficiently small wax crystals for preserving the diesel fuel fluid by, say, heating the fuel, he would, nevertheless, be unable to use his invention because he would find the result already protected for someone else.

This problem of a novel but yet too broad claim is only marginally discussed in literature. Bruchhausen "Formulierung der Patentansprüche und ihre Auslegung" GRUR 1982, 1/3 says that the permissible degree of abstraction in patent claims is difficult to define. A functional term for the first solution which would reserve all further solutions to the first patentee would touch on the borders of patent law. Krasser "Lehrbuch des Patentrechts" 4.ed. 1986 holds at p. 319-320 that it is no valid objection that wide claims may impede innovation by making further inventions dependent. Cornish "World Intellectual Property Guidebook, United Kingdom" (1991) justifies at section 4-038, 5-065 - 5-067 broad claims to a compound going beyond the worked example. In spite of the lack of skepticism in literature such broad claims have again and again occupied national courts and the Boards of Appeal at the EPO.

Under the old United Kingdom patent law it was a ground for invalidity if the complete specifications did not sufficiently and clearly ascertain the scope of the monopoly claimed or if its scope was ambiguous. Lord Justice Romer has put it 1935 in the Non-Fume-case (52 RPC 231/243) as follows: "... The patent will be a public nuisance, hindering and embarrassing those persons engaged in the particular art, from carrying on their legitimate trade or business." Undue width or ambiguity was ground for revocation under section 32 (i) of the patent act 1949. But in that very Non-Fume-case it was admitted that the monopoly may be defined by reference to the result achieved and that the proportions of the device - an ashtray built to prevent smoke from cigarette ends to escape - need not be claimed in all its details if the person skilled in the art could ascertain the required shape by tests not involving inventive effort (see also Ford "Funktionelle Ansprüche" - which he favours - in GRUR 1985, 249).

But the dilemma posed itself in the Genentech-case (Genentech Inc's Patent 1989 RPC 147 - 287) to the Court of Appeal. The court found himself confronted with the wide claim "Human tissue plasminogen activator (commonly abbreviated t-PA) as produced by recombinant DNA-technology". As to the generality of the patent claim the Lords came to the unanimous conclusion, most clearly phrased by Lord Justice Mustill (ibidem at p. 260): "I now consider it clear that this is a patent which should never have been granted, at least in its present form." Nevertheless, the British Patent Act 1977, closely modelled in its section 14 (3),(5), 72 (1) to Art. 84, 83, 100 EPC, did not allow undue and unsupported width of a claim as a ground for invalidity. This dilemma was discussed at length in the Genentech decision. The judges found a way out by denying inventive step.

For the understanding of the following German decision it must first be said that in German patent law the "problem" underlying an invention is understood as the result objectively achieved by the invention (GRUR 1987, 510/511 - Mittelohrprothese (inner ear prothesis). Under the old law, before 1978, the BGH held, that defining a problem cannot be an invention. Rather, the solution to the problem is the invention. Hence it was held insufficient if the claim merely described the result to be achieved and not the solution by which such result was obtained. In the Acrylic-fibre-case (BGH GRUR 85, 31 -Acrylfasern) it was for this reason that the BGH revoked a patent directed to acrylic fibres defined by certain parameters for fibre stability and for shrinking properties.

In a later decision Polyester fibres (BGH 1991 OJ EPO 408 = GRUR 91, 518) the BGH concurred to the general practice of the EPO T 292/85 - 1989 OJ EPO 275 = GRUR Int 1990, 61 - Polypeptide expression/GENENTECH that in many technical fields the use of general terms such as "carriers", "resilient means", "amplifying means" is current practice in spite of the fact that they may embrace special embodiments, developed with or without inventive effort. The BGH decision was handed down in an opposition procedure concerning a patent for polyester fibres where an important feature of the teaching in claim 1 was the use of polyesters as starting materials selected according to their chemical composition and melting properties. The Federal Patent Court held that the criteria rendered the selection unduly difficult. The Federal Court of Justice decided for the patentee since the example in the specification was at least one possible way to work the invention and, lacking findings to the contrary, the court took it for granted that the person skilled in the art could find further starting materials without undue or inventive effort. Then it would be immaterial that the generic criteria may embrace also polyesters invented in future or some starting material which would not prove suitable for the production of the polyester fibres.

While the above decision T 409/91 rather emphasized the limits of allowed generalization, there is, nevertheless, no real conflict between BGH Polyester fibres and EPO Fuel oils/EXXON, since the BGH took the vital point for granted that there were further starting materials in the state of the art beyond the example given in the specification. In T 409/91 Fuel oil/EXXON the person skilled in the art had no further means at his disposal to achieve the desired smallness of wax crystals.

In US Patent Law, it is an established principle under 35 USC § 112 that the width or generality of the claim must be commensurate to the enabling disclosure (in re Fisher 427 F. 2d 833 = 166 USPQ 18; Amgen Inc. v. Chugai Pharmaceutical Co. Ltd. 927 F. 2d 1200/1214 (Fed. Circ. 1991); Chisum and Jakobs in "World Intellectual Property Guidebook, United States" (1992) at 2-132 - 136. A single embodiment offers more easily enabling disclosure for a broad claim in the field of mechanical or electric elements, fields which are governed by predictable factors. In cases involving unpredictable factors, such as most chemical reactions and physiological activity, the scope of enablement varies inversely with the degree of unpredictability of the factors involved. If a claim is not commensurate to the disclosure, by those standards, the consequence is invalidity.

The Boards of Appeal of the EPO used very liberal language when dealing with the frequent objections that the claims were too broad. While the actual cases may well have justified generic terms in the claims the reasoning was such that it encouraged broad claims without proper boundaries.

In EPO T 292/85 - 1989 OJ EPO 275 = GRUR Int 1990, 61 - polypeptide expression/GENENTECH the claim was directed to a recombinant plasmid suited for transformation of a bacterial host. The plasmid should use its own regulon to express a foreign DNA introduced into the plasmid. The opponents objected that the claim comprised unsuitable plasmids on one hand and undetermined future plasmids on the other. The Board said (ibidem at 283, No. 3.1.1, 3.1.2):

"Recombinant plasmids embrace, as components, various regulons which have not yet been provided and may, one day, represent inventions on the basis of some merit of their own. The same applies to the basic plasmid which has been modified to possess the characteristics of the claim. The original plasmid might have complex structures to be developed in the future. ... The suggested features in the claims are essentially functional terms in this particular context, in spite of structural connotations, and may cover an unlimited number of possibilities. It follows that the features may generically embrace the use of unknown or not yet envisaged possibilities including specific variants which might be provided or invented in the future. The Board concurs with the decision of another Board (T 68/85 - 3.3.1, "Synergistic herbicides" OJ EPO 1987, 228) in which the possibility of using functional terminology in claims was approved if "such features cannot otherwise be defined more precisely without restricting the scope of invention" and if their reduction to practice was not an undue burden."

In the later decision EPO T 81/87 - 1990 OJ EPO 250 - Prä-pro-rennin/COLLABORATIVE, cells were claimed containing genetic material derived from recombinant DNA-material and capable of expressing bovine rennin. The Board ruled that the claims where not without formal support since it would be unfair to restrict the claims to the exemplified strain in the disclosure excluding those which may be used in future. This decision followed the earlier decision T 292/85 saying (ibidem at 347 No. 4.7):

"This decision specifically discussed the broadening of such features to embrace means not yet existing and to be discovered in the future. Unless claims with such functional connotations are allowable, no worthwhile protection is provided against a third party which faithfully repeats the process of the patent and obtains new but equally useful variants of the invention."

The reasoning of both decisions dealt with generalization or functional terms in describing auxiliary means such as plasmids serving as carriers for a new expression scheme in order to use them to transform host cells or, respectively, classes of cells to be used for the expression of bovine rennin.

In contrast the famous Harvard onco mouse case dealt with the generalization of the claimed result. In that case (EPO T 19/90 - 1990 OJ EPO 476 = GRUR Int 90, 978) a method was claimed to introduce an activated oncogene sequence into a non-human mammalian animal at a stage no later than the 8 cell-stage. The description disclosed a mouse treated that way. The examination division had denied the patent for insufficiency of disclosure - Art. 83 EPC - since it could not be assumed that the sole example described in the application - that of mice - could be extended to all other mammals. The Board of Appeal overruled and stated (ibidem at 483 No. 3.3):

"However, the mere fact that a claim is broad is not in itself a ground for considering the application as not complying with the requirement for sufficient disclosure under Art. 83 EPC. Only if there are serious doubts, substantiated by verifiable facts, may an application be objected to for lack of sufficient disclosure."

The Board held that there were indications to carry out the invention on other mammals than mice and that there were no verifiable facts which could cast serious doubt on the possibility for a skilled person to carry out the invention as claimed.

Let aside the burden of proof problem in such a case, the question remains, what to do if later development reveals indeed that other onco-mammals cannot be made by the same process as the onco-mouse but that the process requires inventive alterations to produce other onco-mammals. If in view of such later knowledge the old claim really proves too broad, what are the means of redress?

Case law shows that opponents arguing open ended claims have been unsuccessful, that objection being only one under Art. 84 EPC, clarity, which is neither ground for opposition nor for nullity on the national level. Art. 84 EPC becomes relevant in opposition only when the claims are altered, since altered claims must meet the requirement of clarity (EPO T 301/87 - 1990 OJ EPO 335/342 = GRUR Int 1991,121 - Alpha-interferons/BIOGEN). For sufficiency of disclosure, however, it was only required that the description contained at least one workable example (EPO T 292/85 - 1989 OJ EPO 275 = GRUR Int 1990, 61 - Polypeptide expression/GENENTECH). That was held to be sufficient to justify the broad claim.

The Fuel oil/EXXON decision T 409/91 takes a great step further by challenging unduly broad claims not just under Art. 84, but also under Art. 83 EPC which latter constitutes a ground for opposition and for nullity. The Board says:

"Thus, a claim may well be supported by the description in the sense that it corresponds to it, but still encompasses subject-matter which is not sufficiently disclosed within the meaning of Art. 83 EPC, as it cannot be performed without undue burden or vice versa."


"In the Board's judgement, the disclosure of one way of performing the invention is only sufficient within the meaning of Art. 83 EPC if it allows the person skilled in the art to perform the invention in the whole range that is claimed ..."

Whether that is the case or not, must be answered not on the basis of a presumption in favour of the applicant but by weighing the balance of probabilities in each individual case.

This result comes very near to that found under US-law: the scope of the claims must be commensurate with the disclosure. Indeed, the Board says at No. 3.3:

"Furthermore, Art. 84 EPC also requires that the claims must be supported by the description. In other words it is the definition of the invention in the claims that needs support. In the Board's judgement this requirement reflects the general legal principle that the extent of the patent monopoly, as defined by the claims, should correspond to the technical contribution to the art in order for it to be supported or justified (see T 133/85 - 1988 OJ EPO 441). This means that the definition in the claims should essentially correspond to the scope of the invention as disclosed in the description."

If the definition in the claim is unduly broad, this is, as cited, also a matter of sufficient disclosure under Art. 83 EPC so that revocation will be the consequence not only during grant but also in opposition and in nullity proceedings.

Functional and generic claims are only allowable

"if a number of alternatives capable of performing the said function would be at the disposal of the person skilled in the art, either after reading the description or on the basis of his common general knowledge."

In the case given the description disclosed just one additive to obtain the claimed result. Other means were neither taught nor within the general knowledge of persons skilled in the art. Then the disclosure was not sufficient to justify a claim to the result in general i.e. to a diesel fuel with small size wax crystals at low temperature.

There is certainly a turn in case law by opening the opposition procedure to the argument of unduly broad claims. But how far reaching is the turn? Can we derive a consistent pattern? I would believe that the following pattern could serve as an assay.

1. The extent of the patent monopoly as defined by the claims shall correspond to the scope of the invention as disclosed in the description. If the claim is not commensurate with the disclosure, the claim is invalid not only for lack of clarity but also for insufficiency of disclosure - Art. 83 EPC.

EPO T 409/91 Fuel oils/EXXON
US-case law

2. If the extent of the patent monopoly is wide because of claiming not just the solution described but a result or the problem solved or because of using functional terms and definitions, the following requirements should be met:

    EPO T 68/85 - 1987 OJ EPO 228 = GRUR Int 1987, 698 - Synergistic herbicides/CIBA GEIGY

    EPO T 292/85 - 1989 OJ EPO 275/283 = GRUR Int 1990,61 - Polypeptide expression/GENENTECH

    EPO T 409/91 Fuel oils/EXXON

    and must be obvious in a way that the person skilled in the art can, without undue burden, reduce the generic features to practice.

    EPO T 68/85 - 1987 OJ EPO 228 - Synergistic herbicides/CIBA GEIGY

    3. If the generalized features are auxiliary means, while the core of the invention is directed to something else, the balance of probability that the invention can be used with other auxiliary means should be weighed in favour of the applicant.

    EPO T 292/85 - 1989 OJ EPO 275 - Polypeptide expression/GENENTECH for plasmids

    EPO T 81/87 - 190 OJ EPO 250 - Prä-pro-rennin/COLLABORATIVE for classes of cells to be used as hosts

    4. If the generalized feature relates to a class of starting material or to a class of end-products, then, like under No. 2 above, several members of the class must be available or respectively obtainable

    5. When auxiliary means or starting materials are indicated by general terms there is no insufficiency of disclosure even if some individual members are unsuitable,

    EPO T 292/85 - 1989 OJ EPO 275 - Polypeptide expression/GENENTECH

    BGH 1991 OJ EPO 408 = GRUR 91, 518 - Polyester fibers.

    6. In cases where classes of end-products or starting materials, results or functions are claimed, the indication of one way to work the invention is sufficient for the disclosure only

    EPO T 409/91 Fuel oils/EXXON

    7. If it is not obvious that several ways are available to work the invention, it should be up to the applicant in any state of the procedure to indicate further ways. If several alternatives are indeed within the general knowledge of a person skilled in the art, the applicant must be able to make such indications.

    8. In chemistry and biology it is as a rule more questionable whether the general knowledge comprises alternative ways of solution than in the mechanical field.

    Judicial experience in the US in re Fisher 427 F 2d 833

    We must not hope that any rules dealing with allowable generality of claims would ever work perfectly. We have to live with the problem that claims are granted too broad for fear of unduly restricting the protection of an invention and, in other cases, too restricted for fear to monopolize what was not invented. Were the problem really hinges, is at the implementation of Art. 69 EPC. If we take the Harvard onco mouse as an example: if the claim would have been restricted to the process of making mice cancerogenous, it is difficult to conceive how "purposive construction" as practiced in Great Britain (House of Lords 1982 R.P.C. 183 = GRUR Int 1982, 136 - Catnic; Court of Appeal 1989 R.P.C. 69 = GRUR Int 1990, 474 - Epilady) could ever result to assimilate cats or rats to mice, if it proves really true that you can use the same process as for mice also for cats and rats. The German two step determination of the scope of protection is more apt to offer flexible results: the first step is claim interpretation and the second step is the scope of equivalents. Equivalent are means offering same or nearly same results and being within reach of a person skilled in the art, if he is not required to invent but knows the patent. If the same process can be performed with cats and rats also they may well be equivalents in Germany. Proper claim definition ex ante is evidently a far more crucial problem under the British way of determining the scope of protection than under the German way. But the language of Art.69 EPC is certainly more in favour of the British way.

    One way or the other: it will always be a problem that patents may issue with too broad claims, and it is the merit of the Fuel oils/EXXON decision to open the way for later remedy.

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