When is a decision not a decision? When it is an intermediate conclusion

In T 2194/22, the Board of Appeal dismissed an appeal against the decision of the Opposition Division, following remission, to maintain the patent on the basis of a request that was essentially identical to a request that had not been admitted in the previous appeal proceedings (T2371/18). The Board of Appeal held that the admission of the request following remission to the Opposition Division was not precluded under the principle of res judicata because the decision of the Board of Appeal not to admit the request in the first appeal proceedings was not part of the “final” decision, but an intermediate step in reaching this decision. The Board of Appeal also held that a new objection raised by the Opposition Division following remission changed the procedural and factual circumstances such that admission of the request was also not precluded by the binding effect of ratio decidendi under Art. 111(2) EPC. 

This decision is interesting because it highlights the differences in the binding effects of res judicata and of ratio decidendi under Art. 111(2) EPC, and it excludes from the binding effect of res judicata a decision based on a specific procedural situation arising in the first appeal proceedings. 

Legal background: The binding effects of earlier decisions in proceedings following remission

Art. 111(1) EPC allows the Board of Appeal to remit a case to the department of first instance for further prosecution (subject to Art. 11 RPBA 2020). Art. 111(2) EPC binds the department of first instance to the ratio decidendi of the Board of Appeal “in so far as the facts are the same.” The ratio decidendi of a decision is the ground or reason for making it, the point in the case determining the outcome, and is found in the “Reasons for the Decision”. Therefore, if the relevant facts remain the same during proceedings following remission, the department of first instance cannot come to a different decision to the Board of Appeal. 

Res judicata is not a term used in the EPC but is a legal principle that a case for which there has been a final judgment and that is no longer subject to appeal cannot be raised again in the same or a different court. The purpose is to preclude relitigating cases that have already been decided. Decisions of the Boards of Appeal have the same status as court judgments. The principle of res judicata applies in proceedings following remission, the department of first instance and any further appeals being bound by the decision of the original Board of Appeal. 

While a patent proprietor is not prohibited from filing new claim requests following remission to the department of first instance for further prosecution, such requests must be in accordance with the principles of res judicata and ratio decidendi and should build upon the situation that existed at the end of the appeal proceedings that lead to the remittal. 

Case background 

T 2194/22 relates to EP2508830 owned by ConocoPhillips Company and opposed by Linde GmbH on multiple grounds, including added subject matter. The patent relates to a vertical heat exchanger configuration for an LNG facility. The claims were directed to a method of transferring heat from a cooled fluid to a refrigerant in a heat exchanger having a defined configuration. During the prosecution of the application, claim 1 was amended to include features from the description, including the level to which the heat exchanger core was submerged in the liquid phase refrigerant. The opponent argued that this amendment was an unsupported intermediate generalization. The proprietor filed a number of auxiliary requests in response to the notice of opposition, including AR2, which further limited the definition of the level of submersion based on the description and added further definitions of the configuration of the heat exchanger and method. Following the summons to oral proceedings, the proprietor filed further auxiliary requests and reordered the original auxiliary requests such that AR2 became AR3. The Opposition Division maintained the patent on the basis of new auxiliary request 1, which included features from a table referred to in the description in relation to the drawings. 

The opponent appealed on various grounds, including added subject matter, arguing that one parameter shown in the table and in the drawing, but not referred to in the description, was missing from the claim, resulting in an unallowable intermediate generalization. The proprietor also appealed against the revocation of the main request and responded to the opponent’s appeal and included the remaining auxiliary requests from the opposition proceedings, including AR3, in its submissions. The Board of Appeal in T 2371/18 agreed with the opponent on the point of added subject matter and decided that the main and first auxiliary requests were not allowable for this reason. The proprietor requested permission to file a late request (auxiliary request II “new”) to amend the claim to include the missing feature from the table, but the Board of Appeal did not admit this as being detrimental to procedural economy. The Board of Appeal remitted the case to the Opposition Division for further prosecution based on AR3 as this request had not been examined nor had the opponent provided any argument as to why it was not allowable. 

Following remission, the Opposition Division issued an opinion with objections to AR3 on the grounds of added subject matter in relation to the amended definition of the level of submersion. The proprietor responded by filing a new amended request corresponding to the non-admitted auxiliary request II “new” from the first appeal proceedings. The Opposition Division admitted this request and maintained the patent in amended form. 

The opponent appealed on various grounds, including that the decision in T 2371/18 not to admit auxiliary request II “new” was res judicata and so this request could not be admitted into these later proceedings. 

Was the decision not to admit auxiliary request II “new” res judicata? 

The Board of Appeal decided that the decision not to admit auxiliary request II “new” was not the “final conclusion” and therefore “the strict application of the principle of res judicata is not adequate for decisions on the non-admittance of the parties’ submissions, such as a late-filed claim request, in as far as such decisions are intermediate conclusions based on a specific procedural situation.” Noting that such decisions are selective and dependent on circumstances that could change, the Board of Appeal held that “Extending the principle of res judicata to such decisions could be detrimental to the flexibility necessary to respond to relevant factual and procedural circumstances of the case to guarantee fair proceedings.” (Reasons 2.2.6)

Was the decision not to admit auxiliary request II “new” in the first appeal proceedings the ratio decidendi binding on the Opposition Division under Art. 111(2) EPC? 

The Board of Appeal decided that the Opposition Division’s objection to AR3 was not the same as the reason for refusing the main request and 1st auxiliary request in T 2371/18 and therefore the binding effect of Art. 111(2) did not apply. While the new objection concerned the same ground for opposition (added subject matter) and the same parameter (the degree of submersion of the core), the technical question raised was different to that considered previously. This therefore represented a new development in the proceedings that could justify the admittance of a new request. Furthermore, the fact that this was a new objection meant that one of the reasons for refusing admittance of auxiliary request II “new” in the previous appeal proceedings, that the proprietor had known about the objection for some time before filing the late request, did not apply and there was no delay justifying refusal to admit for procedural reasons. 

Does the new request build upon the situation that existed at the end of the appeal proceedings? 

The new request was not strictly convergent with AR3 because it omitted certain features. However, the omission of one of these features (relating to an LNG process) had previously been held by the Board of Appeal not to contravene Art. 123(2), and the other (the location for the introduction of the refrigerant) made no difference to analysis of inventive step, as evidenced by the opponent’s unamended objections in this respect. 

The Board of Appeal noted that “the prosecution of a case after remittal should in principle build upon the situation that existed at the end of the appeal proceedings that led to the remittal” (Reasons 2.5.2). 

According to the ratio decidendi from T 2371/18, “the original disclosure consisted of the simultaneous provision of all parameters of Table 1 due to the interaction among them”. Consequently, amending claim 1 to add the submersion range defined in Table 1 required that all other parameters from the table be included as well if the new request was to follow the reasoning of the Board of Appeal in T 2371/18. This, in turn, meant that the amendment should result in a request that corresponds to auxiliary request II “new” if it was to follow properly from the situation that existed at the end of the previous proceedings. 

Conclusion 

While the issues discussed above are not common in EPO Appeal proceedings, they do provide guidance in some areas: 

The presence of an auxiliary request filed in the initial response to the opposition was key to the decision to remit for further prosecution. While the auxiliary request in question represented one of a series of alternative lines of amendment to address a ground of opposition in relation to one particular technical parameter, it still provided a route for amendment to achieve a claim that followed on from a series of requests based on one of the other auxiliary requests.

Convergence is only one consideration for discretion to allow amended requests. It is also important to follow the reasoning of previous decisions of the division or board.