T 0367/20 04-10-2023

1. Added subject-matter of granted claims - Article 100(c) EPC

1.1 Under Article 123(2) EPC, the European patent application or the European patent may not be amended to contain subject-matter which extends beyond the content of the application as filed. Subject-matter implicitly disclosed to the skilled person, using common general knowledge, is part of the content of the application as filed. Implicitly disclosed subject-matter must be a clear and unambiguous consequence of what is explicitly mentioned (Case Law of the Boards of Appeal, 10th edition 2022, II.E.1.3.3).

1.2 The respondent submitted that the subject-matter of the claims of the patent as granted extended beyond the content of the application as filed. The objections of added subject-matter concern the following amended claim features:

- feature M5.1 in claim 1

- features M12, M13 and M14 in claims 1 to 3

1.3 Claim 1, feature M5.1

1.3.1 The parties submitted the following two alternative interpretations of feature M5.1 ("a first switching pipe which is connected to the fluid flows in parallel with the third heat exchanger"):

(a) the fluid flows are in parallel with the third heat exchanger (which would add subject-matter and would lead to an inescapable trap under Article 123(2) and (3) EPC)

(b) the first switching pipe is in parallel with the third heat exchanger (which is undisputedly disclosed in the application as filed)

The wording of claim 1 as granted is arguably unclear. Having said this, the requirements of Article 84 EPC play no role in the present opposition appeal proceedings (G 3/14, Reasons 55), and claim 1 as granted must be interpreted as it stands (see T 874/97, Reasons 2.1).

For the reasons set out below, the Board adopts interpretation b). Interpretation a) could in the Board's view only be considered viable if feature M5.1 were to be interpreted in isolation, i.e. out of context.

1.3.2 A claim feature must, however, not be interpreted in isolation but in the context of the whole document it forms part of. The context to be considered for the interpretation of a feature in a claim does therefore not only include the other features in that claim and other claims but also the description and the drawings.

1.3.3 The general principle that the claims of a patent, being a part of a document as a whole, need to be construed in their context was recognised early in the case law and has also been understood to underlie Article 69 EPC (see T 556/02, Reasons 5.3, fourth paragraph and, more recently, T 3097/19, Reasons 29.2). Moreover, the principle that patent claims must be interpreted through the eyes of the person skilled in the art, who should try with synthetical propensity to arrive at an interpretation of the claim which is technically sensible and takes into account the whole disclosure of the patent (established case law; see Case Law of the Boards of Appeal, 10th edition 2022, II.A.6.1, first paragraph) was formulated for the first time with reference to Article 69 EPC (see T 190/99, Reasons 2; see also T 396/99, Reasons 3.5, in which the same board examined the patentability of the claimed subject-matter with reference to Article 69 EPC).

1.3.4 Also the limitation on the weight which can be given to the description in relation to the claims was already in earlier case law derived from Article 69(1), first sentence, EPC (see T 1018/02, Reasons 3.8, concerning Article 123(2) EPC). This has been taken up recently and referred to as the primacy of the claims (see T 1473/19, Reasons 3.16.1; T 450/20, Reasons 2.15; T 73/19, Reasons 2.2), which in particular prohibits reading features into the claims which are only present in the description or the drawings.

1.3.5 It was set out in T 1473/19 (Reasons 3.11.3 and 3.11.4) that the first step in determining the extent of protection in accordance with Article 69 EPC consists in determining the claimed subject-matter under the "general principles" of claim interpretation under Article 1 of the Protocol on the Interpretation of Article 69 EPC (without taking account of equivalents under Article 2 of the Protocol on the Interpretation of Article 69 EPC at this stage; if required at all, this is only done in infringement proceedings as a second step following claim interpretation).

It was further set out in T 1473/19 (Reasons 3.12, 3.12.1 and 3.19) that the interpretation and determination of the subject-matter of the same claim in the same opposition (appeal) proceedings before the EPO should be uniform and consistent, including for the purpose of Article 123(2) and (3) EPC (the application of Article 69 EPC being mandatory for the determination of the "technical subject-matter of the claims" under Article 123(3) EPC, in accordance with G 2/88, Reasons 4 and 4.1).

Moreover, it was stated in T 1473/19 (in Reasons 3.14 and 3.11.3, last sentence) that the EPO in opposition (appeal) proceedings and the national courts and the UPC in revocation proceedings have concurrent jurisdiction on (post-grant) patent validity and that national courts apply the rules for the interpretation of claims in Article 69 EPC also in revocation proceedings. The present Board additionally notes that the grounds for opposition under Article 100(a) to (c) EPC correspond literally - including in their reference to the "subject-matter" of the patent - to the grounds for revocation under Article 138(1)(a) to (c) EPC (see also Article 65(2) UPCA), and that Article 68 EPC regulates the effect of the revocation or limitation of a European patent in an identical manner for both opposition and revocation proceedings. As to examples of national case law on claim interpretation according to Article 69 EPC in respect of revocation proceedings see:

- Court of Appeal of England and Wales, 14.01.2022, [2022] EWCA Civ 20, Reasons 32, referring to Article 69 EPC and Article 1 of the Protocol on its interpretation in relation to novelty, inventive step and sufficiency of disclosure; High Court of England and Wales, 07.03.2013, [2013] EWHC 467 (Pat), Reasons 67, addressing the primacy of the claims according to Article 69 EPC;

- German Federal Court of Justice, 15.12.2020, X ZR 180/18, Reasons I.5.b), applying Article 69 EPC for determining the subject-matter of the patent ("Gegenstand [...] des Patents") in relation to novelty and inventive step; German Federal Court of Justice, 04.02.1997, X ZR 74/94, Reasons 6a, excluding equivalents from the assessment in revocation proceedings;

- Court of Appeal of Paris, 19.10.2021, N°2017/22624, applying Article 69 EPC for claim interpretation (also) in relation to inventive step; Court of Justice of Paris, 24.03.2023, N°20/03907, Reasons 44 and 52, applying Article 69 EPC for claim interpretation in relation to added subject-matter;

- Court of Appeal of The Hague, 27.10.2020, 200.261.833/01, Reasons 4.5 and 4.45.2 (penultimate sentence), referring to a two-step approach in determining the extent of protection under Article 69 EPC and stating that equivalents are not to be taken into account in the assessment of novelty, inventive step and sufficiency of disclosure;

- Federal Supreme Court of Switzerland, 15.12.2020, 4A_317/2020, Reasons 3.1. and 3.3.2, stating that the principles of claim interpretation according to Article 69 EPC are also applicable when assessing novelty;

- Higher Regional Court of Vienna, 08.06.2018, 133 R 21/18p, Reasons 1.8, referring to claim interpretation according to Article 69 EPC in relation to inventive step;

- Court of Appeal of Barcelona, 24.11.2016, ROJ: SAP B 9303/2016, Reasons 16 to 19, applying Article 69 EPC (also) for determining the claimed invention ("el objeto de la invención") in relation to novelty and inventive step.

1.3.6 For the above reasons, the present Board considers that the principles of claim interpretation as set out in Article 69 EPC and Article 1 of the Protocol on its interpretation should be applied when establishing the meaning of the claimed features and determining the claimed subject-matter in the present proceedings. Accordingly, the description and the drawings must be considered when interpreting the claims, taking due account of the primacy of the claims.

1.3.7 The claims to be interpreted for assessing compliance with Article 123(2) EPC are the claims as granted. These must be interpreted in the context of the whole document they form part of, i.e. the whole disclosure of the patent as granted. Accordingly, it is the description and the drawings of the patent as granted which must be used for the interpretation of the claims as granted (see T 450/20, Reasons 2.16; see also the reference to the "description and drawings" and the "European patent" in the first sentence of Article 1 of the Protocol on the Interpretation of Article 69 EPC; moreover, if - as in the present case - an amended description was submitted for the set of claims which was then granted, only the description of the patent is part of the text of the "European patent" which may be examined pursuant to Article 113(2) EPC).

1.3.8 To assess whether an amended patent claim contains added subject-matter under Article 123(2) EPC, the claimed subject-matter must first be determined by interpreting the claim (i.e. establishing the meaning of the claimed features) from the perspective of the person skilled in the art. In a second step, it must be assessed whether that subject-matter is disclosed in the application as filed. In other words, the claim interpretation adopted by the deciding body defines the subject-matter which must be disclosed in the application as filed. In the present Board's view, this approach reflects what the Enlarged Board of Appeal stated in G 2/10, Reasons 4.5.2: "Whether the skilled person is presented with new information depends on how he or she would understand the amended claim, i.e. the subject-matter remaining in the amended claim and on whether, using common general knowledge, he or she would regard that subject-matter as at least implicitly disclosed in the application as filed." (emphasis added).

1.3.9 In the case at hand, interpretation a) and interpretation b) of claim 1 as granted result in different claimed subject-matter and are mutually exclusive in that claim 1 either requires the first switching pipe or, alternatively, the fluid flows to be "in parallel with the third heat exchanger". Contrary to what was indicated by the respondent, it cannot be required of the patentee that the claimed subject-matter according to either of these mutually exclusive interpretations be disclosed in the application as filed. Only the subject-matter which is actually claimed - as opposed to subject-matter which is merely hypothetically claimed - must be disclosed in the application as filed. In this situation, the deciding body must not adopt two mutually exclusive claim interpretations simultaneously and must - if decisive for the outcome of the case - not leave the interpretation in that regard open either. Rather, the deciding body must consider which of the two claim interpretations is correct. As stated above, this interpretation defines the claimed subject-matter which must be disclosed in the application as filed.

1.3.10 For the sake of completeness, the Board notes that whether or not two claim interpretations are in a given case mutually exclusive depends on the specific circumstances of the case which must be assessed by the deciding body. The present case concerning two mutually exclusive interpretations of a certain claim feature must in particular be distinguished from situations in which a claim feature can be interpreted in a broad manner to encompass "a multitude of possibilities" (see T 1408/04, Reasons 1). In such a case, these are different embodiments of the same, broad subject-matter.

1.3.11 Turning to the interpretation of Feature M5.1, the Board notes that this feature refers to a first switching pipe which is connected to "the fluid flows". Although a definite article is used, "the fluid flows" referred to in this feature are not previously introduced and defined in the claim.

1.3.12 As argued by the respondent, the phrase "fluid flows" in feature M3 ("a fluid circuit [..] through which fluid flows") cannot be understood as an antecedent of the "fluid flows" in feature M5.1 since the word "flows" is used as a verb in M3, contrary to the use as a noun in M5.1. Likewise, the phrase "the fluid flows" in features M8 and M9 also concerns an action and is therefore not decisive for ascertaining the meaning of feature M5.1 either.

1.3.13 Feature M11 defines "a second switching pipe which is connected to the third heat exchanger in parallel and which is connected to the first switching pipe in parallel". The respondent argued that the parallel arrangement of the second switching pipe with respect to the third heat exchanger and to the first switching pipe would not necessarily mean that the first switching pipe was also arranged in parallel to the third heat exchanger. The respondent further submitted that feature M5.1 rendered the two parallelisms in feature M11 meaningless. The Board disagrees with the latter. Rather than construing feature M5.1 and feature M11 in isolation such that they contradict each other, the person skilled in the art would interpret them in a complementary manner. Hence, taking account of feature M11 when interpreting feature M5.1 speaks in favour of interpretation b) of feature M5.1 (i.e. that the first switching pipe is in parallel with the third heat exchanger).

1.3.14 The description of the patent as granted, which must be taken into account for interpreting feature M5.1 of claim 1 as granted (see points 1.3.2 to 1.3.7 above), consistently discloses that the first switching pipe is "connected to the third heat exchanger in parallel".

1.3.15 Importantly, this is already the case in the general description of the invention (see paragraph [0015], lines 1 and 2 of column 3), as well as in all embodiments referred to in the description (see paragraph [0039], lines 54 and 55 of column 6; for the second embodiment, see paragraph [0076], lines 45 to 47 of column 10).

1.3.16 Hence, taking account of feature M11 and the description, the person skilled in the art would adopt interpretation b) of feature M5.1. This is the arrangement defined in the corresponding feature of originally filed claim 1 ("a first switching pipe which is connected to the third heat exchanger in parallel") and therefore as originally disclosed.

1.3.17 As to "the fluid flows" in feature M5.1, the person skilled in the art knows that the connection of two elements in parallel in a hydraulic circuit requires the use of pipes. These pipes form the hydraulic circuit but are separate from the elements they connect. In view of their common general knowledge and taking account of feature M11 and the content of the description and the figures (see Figures 1, 2, 3 and 5), the person skilled in the art understands "the fluid flows" in feature M5.1 as the hydraulic lines (i.e. the pipe sections of the hydraulic circuit) to which the first switching pipe has to be connected to be arranged in parallel with the third heat exchanger. Such pipe sections are necessarily implied by originally filed claim 1 and thus form part of the subject-matter disclosed in that claim.

1.3.18 The respondent submitted Figure OP in the oral proceedings before the Board. Since Figure OP is, according to the analysis provided below, not relevant for the outcome of the case, the question raised by the appellant concerning its admittance under Article 13(2) RPBA 2020 does not need to be addressed.

1.3.19 In substance, the respondent argued that Figure OP demonstrated that an implementation of feature M5.1 according to interpretation a) was technically feasible. The respondent argued that feature M11 could be complied with even if the first switching pipe was not arranged in parallel with the third heat exchanger, providing Figure OP (reproduced below) in support of its arguments.

FORMULA/TABLE/GRAPHIC

This is not convincing.

1.3.20 Firstly, the proposed circuit is not a device the skilled person would contemplate when implementing the invention of claim 1.

The respondent proposes a first switching pipe (62) running through a tank (55) and connected to the pipe feeding the third heat exchanger (53). Two "fluid flows" are connected to this first switching pipe (53) at a location between the tank (55) and the third heat exchanger (53).

Feature M6 defines "a control apparatus which switches between a flow of the fluid to the third heat exchanger and a flow of the fluid to the heat accumulator tank" (emphasis added).

Feature M7 defines two modes for the claimed device, namely "a heat-accumulation operation mode and a cooling operation mode".

Features M8 and M9 define how the device works in each mode, namely "in the heat-accumulation operation mode, the fluid flows to the first switching pipe, thereby heating the water in the heat accumulator tank, and in the cooling operation mode, the fluid flows to the third heat exchanger, thereby absorbing heat in air" (emphasis added).

As stated by the appellant, the skilled person understands from these features that the flow of the fluid is either directed towards the first switching pipe to heat the water in the tank or to the third heat exchanger to absorb heat in the air. The connection between the first switching pipe (62) and the pipe feeding the third heat exchanger (53) does not make technical sense since it would either feed a hot fluid into a heat exchanger intended to absorb heat in the air or a cold fluid intended to absorb heat in the tank intended for heating water. Thus, this embodiment would not be considered by the skilled person when implementing the subject-matter of claim 1 because it is technically unreasonable.

1.3.21 Secondly, the device proposed in Figure OP does not fall under the subject-matter of claim 1, even if interpretation a) were adopted.

The respondent proposes a "second switching pipe" comprising two portions: a first one arranged vertically between two three-way valves and a second one starting at the lower three-way valve and comprising a horizontal portion.

According to Figure OP, to feed fluid to the third heat exchanger (53) for cooling, fluid must always flow to the first vertical portion of the second switching valve. This is explicitly excluded by feature M12, which defines that "when the heat-accumulation operation mode is changed to the cooling operation mode, the control apparatus is configured to determine whether the fluid which flows out of the first heat exchanger should be made to flow to the second switching pipe or to the third heat exchanger" (emphasis added). Even if a second switching pipe formed by several portions is encompassed by the claim, feature M12 excludes that the fluid can be made to flow to both the second switching pipe and the third heat exchanger as would be necessary when feeding the third heat exchanger (53) of Figure OP.

Furthermore, the flow of fluid to the first portion of the second switching pipe of Figure OP and (subsequently) to the third heat exchanger (53) means that these two elements are connected in series, contrary to feature M11. The expression "connected in parallel" related to a hydraulic circuit has a well-defined meaning and involves parallelism in hydraulic terms. The skilled person reading claim 1 understands that connecting an element in parallel excludes a connection in series, and this applies for the whole of the element.

1.3.22 In view of the above, feature M5.1 does not contain added subject-matter.

1.4 Claim 1, feature M12 ("configured to determine")

1.4.1 The respondent argues that there is no basis for the amendment of feature M12 from "the control apparatus determines" (application as filed) to "the control apparatus is configured to determine" in the originally filed application.

1.4.2 The Board agrees that the literal wording "configured to determine" was not used in the originally filed application. However, considered as a whole, the originally filed application discloses this feature.

In current device claim 1, the skilled person understands "configured to determine" as the control apparatus having the capacity to perform this function (e.g. by sensors, etc.), not just the suitability of being potentially configured to perform the defined action. This capacity is also disclosed in the originally filed application.

Originally filed claim 1 defined the following features (emphasis added):

M6|a control apparatus which switches between a flow of the fluid to the third heat exchanger and a flow of the fluid to the heat accumulator tank |

M12'|and when the heat-accumulation operation mode is changed to the cooling operation mode, thecontrol apparatus determines whether the fluid which flows out of the first heat exchanger should be made to flow to the second switching pipe or to the third heat exchanger based on temperature of the fluid detected by the temperature sensor|

Although the verbs "switches" and "determines" may at first appear to define an action, such an interpretation is not technically sensible for a device claim. A device can only enable an action by providing means (e.g. a control logic and sensors and actuators). The skilled person thus understands that feature M6 cannot be interpreted as if the control apparatus were continuously switching between a flow of the fluid to the third heat exchanger and a flow of the fluid to the heat accumulator tank. Instead, the skilled person interprets features M6 and M12' to mean that the control apparatus must be capable of performing these actions whenever this is needed.

Hence, amended feature M12 only explicitly defines what was implicitly disclosed in granted claim 1, namely that the control apparatus "is configured" to perform the action, and it does not extend the subject-matter of claim 1 compared to the originally filed application.

1.5 Claims 2 and 3, features M13 (the control apparatus is configured to receive a signal from the temperature sensor) and M14 (and further configured to control the flow)

1.5.1 The conclusion of the preceding point on feature M12 (configured to determine) applies mutatis mutandis to features M13 (control apparatus configured to receive a signal from the temperature sensor) and M14 (configured to control the flow of the fluid) in claims 2 and 3. The skilled person understands from the originally filed application (claim 2) that the invention concerns a control apparatus capable of performing the defined actions whenever needed.

2. Remittal - Article 111(1) EPC, Article 11 RPBA 2020

The contested decision concerns solely the ground for opposition based on Article 100(c) EPC and compliance of the auxiliary requests with Articles 123(2) and (3) EPC. The grounds for opposition under Article 100(a) EPC were not addressed in the decision under appeal.

In accordance with Article 12(2) RPBA 2020, the primary object of appeal proceedings is to review the decision under appeal in a judicial manner. Lacking a decision to be reviewed on other patentability requirements and in view of the requests for remittal from both parties, special circumstances within the meaning of Article 11 RPBA 2020 exist, and the Board decides to remit the case to the opposition division for further prosecution (Article 111(1) EPC).