T 1170/20 - Reach through claim and functional definitions

Key points

• Claim 1 is directed to, in translation: "Medium and/or high voltage gas-insulated electrical equipment comprising .... a gas-tight sealed envelope whose interior volume is filled with an electrically insulating gas comprising at least one fluorinated compound whose global warming potential is less than 3500"
• The Board rejects the claim as a reach-through claim. 
• In translation: "The appellant [opponent] argues that the characteristic "an electrically insulating gas containing at least one fluorinated compound with a global warming potential (GWP) of less than 3500" gives the claim a so-called “reach through” character, namely that the claim relates to a chemical compound defined only in functional terms. The Board agrees with the [opponent]."
• "The claim requires an insulating gas in a medium or high voltage gas-insulated electrical apparatus. The skilled person must find among the broad class of fluorinated compounds those having both a GWP of less than 3500 and a suitability for producing an insulating gas in a medium or high voltage apparatus. The argument that any fluorinated compound would be suitable for electrical insulation of a medium or high voltage apparatus does not convince the Board. The applicant rightly argues that significant efforts are being made to replace SF6 as an insulating gas. It is in fact difficult to find other promising solutions"
• The patent mentions classes of gases. "For these classes, a few individual compounds are disclosed as examples [in the patent]. The Board is satisfied that there are fluoroketones suitable for electrical insulation of electrical apparatus as claimed (see documents A3 and A4). However, the rest of these examples are presented without any proof of their suitability. Some of these examples are clearly erroneous, such as "HFO 1336 mzzzM" or "C7F18O", as the respondent itself argues.
• The Board is of the opinion that it is not sufficient to present a few broad classes of fluorinated compounds and a few individual specific examples with a desired GWP without proof that in essence all members of the classes of compounds satisfy all the criteria for suitability as insulating gases for medium or even high voltage switchgear. "

• "the respondent argued that the invention was not aimed at finding all suitable compounds as low GWP insulating gas. On the contrary, an apparatus using such insulating gas was the background against which the invention was made. The current invention aimed at avoiding heat losses by managing the condensate, ensuring that a sufficient amount of insulating gas is in the gas phase." 

• "The Board cannot accept this argument. The requirement of sufficiency of disclosure concerns the invention in its entirety, and not only that part which the applicant or proprietor considers to be the inventive contribution. If any part of the invention defined in the claims cannot be carried out, then that invention may be the subject of an objection for insufficiency of disclosure. Otherwise, speculative patents may have to be granted because their subject-matter relates in part to construction details which can be carried out even though that subject-matter would not be possible in its entirety."

• "contrary to the respondent's claim, the technical field to which a claim relates is irrelevant when it is characterized as being of the "reach-through" type. The essential idea of ​​not allowing claims of this type is explained in the cited section of the Guidelines as follows:  [F-III,9] [Quote from the English Guidelines added, PJL] "A functional definition of a chemical compound ("reach-through" claim) covers all compounds possessing the activity or effect specified in the claim. It would be an undue burden to isolate and characterise all potential compounds (e.g. agonists/antagonists), without any effective pointer to their identity (see F‑III, 1), or to test every known compound and every conceivable future compound for this activity to see if it falls within the scope of the claim. In effect, the applicant is attempting to patent what has not yet been invented, and the fact that the applicant can test for the effect used to define the compounds does not necessarily confer sufficiency on the claim; in fact it constitutes an invitation for the skilled person to perform a research programme (see T 435/91 (Reasons 2.2.1), followed by T 1063/06 (Headnote II)). "

• "This explanation is extended to the present case. The claim covers all compounds having a GWP of less than 3500 and having the function of an insulating gas for medium and/or high voltages. The patent does not contain any clear indication as to their identity, beyond an indication that these compounds contain fluorine. The board pointed out above that the difficulty lies in finding suitable compounds. The respondent simply states and without providing any evidence that a person skilled in the art could find the suitable compounds using only his ordinary skills and given a suitable compound, the GWP could be determined. However, this is exactly the case described in the Guidelines, namely that in reality the respondent is trying to patent what has not yet been invented, and the fact that the effects used to define compounds can be tested does not mean that the claim sufficiently discloses the invention. The claim is in fact an invitation to carry out a search program."

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EPO 

The link to the decision and an extract of it can be found after the jump.

https://www.epo.org/fr/boards-of-appeal/decisions/t201170fu1

2.2 “Reach through” claim

The applicant argues that the characteristic

"an electrically insulating gas containing at least one fluorinated compound with a global warming potential (GWP) of less than 3500"

gives the claim a so-called “reach through” character, namely that the claim relates to a chemical compound defined only in functional terms.

2.3 The Board agrees with the applicant. The claim requires an insulating gas in a medium or high voltage gas-insulated electrical apparatus. The skilled person must find among the broad class of fluorinated compounds those having both a GWP of less than 3500 and a suitability for producing an insulating gas in a medium or high voltage apparatus. The argument that any fluorinated compound would be suitable for electrical insulation of a medium or high voltage apparatus does not convince the Board. The applicant rightly argues that significant efforts are being made to replace SF6 as an insulating gas. It is in fact difficult to find other promising solutions such as some of the fluoroketones according to documents A3 and A4. Insulating power is not the only criterion for suitability. Another difficulty for example, as highlighted by the present patent, is the boiling point. Potential insulating gases must have a boiling point that is not too high. Gases that are too corrosive and harmful are also not suitable for the apparatus according to the claim. Furthermore, it is not only a question of finding insulating gases but also gases with sufficient capacity to extinguish arcs. It is also a question of identifying gases that do not decompose too quickly under the effect of electric arcs. The decomposition products of SF6, for example, seem to recombine sufficiently so as not to empty the SF6 enclosure too quickly, and thus do not seem to require too frequent refilling. The problem seems to be more pronounced with some of the fluoroketones but it is possible to solve it by providing a liquid reservoir as described in document A3.

These considerations show that a large number of conditions must be met for a gas to be suitable for acting as an insulating gas in a high or medium voltage gas-insulated device.

2.4 The respondent argues that the patent discloses examples in paragraph [0015]. However, these examples are also broad classes of compounds, namely fluoroketones, hydrofluoroolefins, hydrofluorocarbons, fluorooxiranes, hydrochloroolefins and hydrofluoroethers.

For these classes, a few individual compounds are disclosed as examples. The Board is satisfied that there are fluoroketones suitable for electrical insulation of electrical apparatus as claimed (see documents A3 and A4). However, the rest of these examples are presented without any proof of their suitability. Some of these examples are clearly erroneous, such as "HFO 1336 mzzzM" or "C7F18O", as the respondent itself argues.

The Board is of the opinion that it is not sufficient to present a few broad classes of fluorinated compounds and a few individual specific examples with a desired GWP without proof that in essence all members of the classes of compounds satisfy all the criteria for suitability as insulating gases for medium or even high voltage switchgear. The Board particularly disagrees with the respondent's assertion that

"[...] the Patent contains sufficient information to enable a person skilled in the art to find, with reasonable effort, suitable variants of fluorinated compounds suitable for the electrically insulating gas of the medium and/or high voltage gas-insulated electrical apparatus defined in claim 1 of the Patent."

The patent in suit does not appear to name the criteria, nor to contain any general information or general guidelines that might guide the skilled person in finding, among the broad classes of compounds claimed, those that satisfy the constraints imposed by the claim.

2.5 Furthermore, the respondent argued that the invention was not aimed at finding all suitable compounds as low GWP insulating gas. On the contrary, an apparatus using such insulating gas was the background against which the invention was made. The current invention aimed at avoiding heat losses by managing the condensate, ensuring that a sufficient amount of insulating gas is in the gas phase.

The Board cannot accept this argument. The requirement of sufficiency of disclosure concerns the invention in its entirety, and not only that part which the applicant or proprietor considers to be the inventive contribution. If any part of the invention defined in the claims cannot be carried out, then that invention may be the subject of an objection for insufficiency of disclosure. Otherwise, speculative patents may have to be granted because their subject-matter relates in part to construction details which can be carried out even though that subject-matter would not be possible in its entirety.

2.6 Further, the Respondent argued by way of example that if a metal having a certain heat capacity or electrical resistance were claimed, it would not be necessary to disclose a list of all possible metals or alloys having that parameter.

The Board is not convinced by this argument. The question whether the effort required involves only ordinary skill and routine practice or whether it represents an excessive burden must be resolved on a case-by-case basis. The difference between the example put forward by the respondent and the claimed insulating gases is of course that the former can be identified using only knowledge and skills normally available to the person skilled in the art, while the latter cannot.

2.7 Furthermore, the respondent argued that considering the present claim to be of the "reach-through" type constituted a misapplication of the Guidelines for Examination, F-III.9.

This chapter of the Guidelines concerned inventions in the field of biotechnology and, more importantly, compounds characterized only by their effect or function. This was not the case here. Rather, the GWP was an accepted and customary parameter that could be determined without difficulty for a given compound.

However, contrary to the respondent's claim, the technical field to which a claim relates is irrelevant when it is characterized as being of the "reach-through" type. The essential idea of ​​not allowing claims of this type is explained in the cited section of the Guidelines as follows:

"A functional definition of a chemical compound (so-called reach-through claim) covers all compounds having the activity or effect specified in the claim. Isolating and characterizing all potential compounds (e.g. agonists/antagonists) without having a clear indication as to their identity (cf. F?III, 1), or checking whether each known or to-be-synthesized compound has this activity, and seeing whether it falls within the scope of the claim, would require an unreasonable effort. In reality, the applicant is trying to patent what has not yet been invented, and being able to test the effects used to define compounds does not necessarily mean that the claim sufficiently discloses the invention; it is in fact an invitation to carry out a research program [...]"

This explanation is extended to the present case. The claim covers all compounds having a GWP of less than 3500 and having the function of an insulating gas for medium and/or high voltages. The patent does not contain any clear indication as to their identity, beyond an indication that these compounds contain fluorine. The board pointed out above that the difficulty lies in finding suitable compounds. The respondent simply states and without providing any evidence that a person skilled in the art could find the suitable compounds using only his ordinary skills and given a suitable compound, the GWP could be determined. However, this is exactly the case described in the Guidelines, namely that in reality the respondent is trying to patent what has not yet been invented, and the fact that the effects used to define compounds can be tested does not mean that the claim sufficiently discloses the invention. The claim is in fact an invitation to carry out a search program.

2.8 Therefore, the ground for opposition under Article 100(b) EPC precludes the maintenance of the opposed patent as granted.