T 2219/18 04-02-2021

1. The appeals are admissible.

2. The Board concurs with the appealed decision that the ground for opposition under Article 100(c) prejudices the maintenance of the European patent as granted (main request), since the inclusion of feature (i) in conjunction with the omission of feature (ii) in granted claim 1 leads to subject-matter extending beyond the content of the application as filed (WO-A).

In the Board's judgement feature (ii) is directly and indissolubly linked to feature (i). In effect, it is evident that "the end segment being swept at an end segment close to or equal to the wing trailing sweep angle" is only technically meaningful in the context of said further omitted features (included in claim 2 and paragraph [0027] of WO-A), which describe the overall geometry and the main structure of the wing tip, with feature (i) representing only a further detail, said end segment being a small portion of the wing tip.

Contrary to the Patentee's view there is clearly a functional and structural relationship between features (i) and (ii), given feature (i) stipulating said end segment angle being close or equal to the wing trailing edge sweep angle, this angle being identical with the angle of the tangent to the second parabolic line (of the wing tip) starting from the wing trailing edge according to feature (ii). A further functional and structural relationship between feature (i) and feature (ii) is given by the fact that the shape and configuration of the wing tip's curved leading edge is essential for maintaining attached flow (hence preventing premature vortex formation too far upstream of the wing tip end segment), as clearly acknowledged in paragraph [0005] (WO-A), thus establishing a link between feature (ii) and the alleged technical effect (i.e. "stabilizing tip vorticity and maintain the vortex position close to the extreme wing tip").

Finally, it is evident from the wording "in one embodiment" in paragraphs [0027] (disclosing feature (ii)) and [0028] (disclosing feature (i)) (see WO-A) that one and the same embodiment is implied, the latter paragraph merely describing a further preferred embodiment based and depending on the former paragraph. Similarly, as mentioned hereinbefore paragraph [0005] indeed confirms that feature (i) (and the alleged technical effect) are directly linked to the "curved leading edge" and the "curved trailing edge" being "designed to achieve optimal results", e.g. as set out in feature (ii) and/or in paragraph [0027] of WO-A.

3. In accordance with the appealed decision (see pages 6 to 8) the features of claim 1 reading "a leading edge (212) curved to maintain attached air flow and defining a first parabolic line from the wing leading edge to a leading end point (228)" and "a trailing edge (216) curved to maintain elliptic loading over the wing tip defining a second parabolic line from the trailing edge to a trailing end point (232)" can only be construed as defining a leading and a trailing edge having, respectively, a curvature in a broad sense. This is based on the following reasons.

First, there is a manifest and evident incompatibility between the feature "first" and "second parabolic line" on the one hand, and the features of dependent claims 3 and 4 (and equivalent passages in the description) in EP-B on the other hand, these latter features including mathematical equations representing curves not even encompassing or including "parabolic lines" (in their general mathematical form), and this for no one of the parameter values corresponding to the indicated parameter ranges (see parameter ranges specified for exponents m1, m2, n1, n2).

Further, "maintain attached air flow" and "maintain elliptic loading" constitute merely an entirely conventional design consideration for a wing and/or wing tip and is inherent on virtually any wing type device. In particular, no specific and concrete technical measure is indicated in claim 1 for achieving these results (going beyond aforementioned non-limiting features).

4. The subject-matter of auxiliary request 1 does not involve an inventive step in view of D2 in conjunction with the skilled person's common general knowledge or with D2A or D2B (Article 56 EPC).

The Board concurs with the appealed decision in that the disclosure of D2 differs from the subject-matter of claim 1 in that the claimed subject-matter provides an aircraft having a "wing trailing edge that exhibits a wing trailing edge sweep angle" (see appealed decision, Reasons, point 8.2.1, 8.2.2), i.e. a wing trailing edge inclined toward the aft of the aircraft by an angle different from 0°. This is undisputedly the starting point considered by the parties for the discussion of inventive step in respect of D2.

The objective problem starting from D2 consists in adapting the wing of D2 to provide an alternative geometry that is to be used on a wing with a trailing edge exhibiting a trailing edge sweep angle different from 0° degrees. From the skilled person's perspective this objective problem results directly from D2, for D2 explicitly suggests applying its technical teaching to F-4 and F-16 XL aircrafts (D2, column 1, paragraph 3, lines 3-7) both having "swept" wings (towards the aft of the aircraft), as well as to any kind of aircraft (see D2, column 1, paragraph 3, lines 9 to 11), e.g. including any aircraft having generally swept wings. In accord with the view taken in the appealed decision (see Reasons, 9.1.3) the skilled person would fit the wing tip of D2 such as to match the root profile of the wing tip to the tip profile of the wing (i.e. as stated in claim 1: the (wing tip) leading edge starting generally tangential with the wing leading edge and approaching a free stream direction at the leading end point; the (wing tip) trailing edge starting generally tangential from the wing trailing edge and approaching the freestream direction at the trailing end point), avoiding any discontinuities which would inevitably lead to drag penalties. Thus, the features already known from D2 will stay unaffected.

As to feature (i) (i.e. "the end segment being swept at an end segment angle close to or equal to the wing trailing edge sweep angle (218)"), the skilled person starting from D2 would implement this feature in an obvious way when fitting the wing tip of D2 to the wing of a F-4 aircraft (as shown in D2A) or of a F-16 XL aircraft (as shown in D2B), given that this feature is clearly already suggested in D2 showing that the "un-swept" wing's trailing edge is approximatively and almost parallel to the end segment of the wing tip. The skilled person would naturally adopt this technical measure, acknowledging that it is advantageous to follow a prudent and cautious conservative design that avoids any possible misalignments and discontinuities (leading to aerodynamic drag) in the wing trailing edge region, as illustrated by D2. In addition, the skilled person would have no reason to substantially deviate from the wing and wing tip design disclosed in D2, based on the implicit reasonable assumption that (as for any prior art in this technical field) it is fundamentally intended and conceived to minimize drag, unless any evidence to the contrary is provided.

Consequently, the skilled person would arrive at feature (i) in an obvious manner, regardless and irrespective of any alleged new (proven or unproven) technical effect, as submitted e.g. by the Patentee.

In particular, the alleged new technical effect that the trailing vortex position would be maintained close to the trailing end point cannot render inventive the claimed subject-matter (contrary to the view of the Opposition Division), if the skilled person would anyway arrive in an obvious manner at the claimed subject-matter independently and irrespectively of said alleged new technical effect. Moreover, as noted by the Opponent and confirmed by the Declaration of Dr. Maughmer (D14), as a matter of fact no experimental evidence or physical arguments are given in EP-B or were submitted by the Patentee, which would support the existence of the alleged new technical effect.

5. Auxiliary request 2 is not allowable for the same reasons as the main request (added subject-matter), as claim 1 likewise includes feature (i) but omits feature (ii).

6. The Opponent's arguments objecting to claim 1 of auxiliary request 3 were taken into consideration by the Board pursuant to Article 13(2) RPBA (Rules of Procedure of the Boards of Appeal) 2020.

The Board considered that exceptional circumstances are given in the present case, for the arguments submitted by the Opponent against claim 1 of auxiliary request 3 during oral proceedings (based on lack of inventive step, starting from D2 in view of the skilled person's general knowledge, D2A or D2B) are entirely identical with the arguments submitted with the statement of grounds of appeal against claim 1 of auxiliary request 1 and for it is immediately apparent that these arguments likewise apply against claim 1 of auxiliary request 3. Indeed, the amendment introduced in claim 1 of auxiliary request 3, according to which the wing tip end segment has a finite length, is a trivial feature (any segment indeed has a finite length) which as such is moreover immediately apparent from D2 (see e.g. second figure from the top on page 1). The Opponent's arguments based on D2 hence likewise apply (unaltered) to claim 1 of auxiliary requests 3. The Patentee likewise implicitly acknowledged this, since it did not consider necessary to add any further comments in response to the Opponent's arguments based on D2.

In view of the above, the Board considers that the Patentee (and any person of ordinary technical knowledge in the field) could readily infer that the Opponent's arguments based on lack of inventive step in the statement of grounds of appeal (starting from D2) would equally apply (without changes) to claim 1 of auxiliary request 3. Consequently, the Opponent's submissions during oral proceedings were by no means unexpected, and indeed almost self-evident. The Board's communication lacking a preliminary opinion concerning auxiliary request 3 cannot corroborate the Patentee's contentions that the Opponent's submissions were late filed. Indeed, in the Board's communication it was only noted that no explicit submissions were made by the Opponent concerning auxiliary requests 2 and 3, thus solely rendering clear that such submissions should be filed if deemed necessary. There is no obligation for the Board pursuant to Article 15(1) RPBA (Rules of Procedure of the Boards of Appeal) 2020 to give any preliminary opinion, let alone on auxiliary requests which were not explicitly addressed by the Opponent.

For the above reasons, the Opponent's objections to claim 1 of auxiliary request 3 were taken into consideration by the Board.

7. The subject-matter of claim 1 of auxiliary request 3 is not inventive (Article 56 EPC) over D2 in view of the skilled person's common general knowledge, or in view of D2A or D2B, the same arguments discussed in relation to claim 1 of auxiliary request 1 applying identically in this case. In effect, as detailed above, the amendment introduced into claim 1 according to this auxiliary request (i.e. "having a length") undisputedly represents a feature known from D2 (see figures), disclosing that the wing tip end segment has a finite length.

8. The Board did not admit into the appeal proceedings auxiliary requests 5 and 6 which represent an amendment to the Patentee's appeal case filed after the notification of the summons to oral proceedings pursuant to Article 13(2) RPBA 2020. The Board's communication giving a preliminary opinion (on the main request and auxiliary request 1) does not represent an invitation or opportunity to submit further auxiliary requests, given the parties' complete case having been set out in their statement of grounds of appeal and in their respective reply, thus auxiliary requests having already been filed with said submissions (as fallback position), taking into account a possible unfavourable opinion of the Board on higher ranking requests.

Moreover, no new or surprising arguments were invoked by the Board in its communication, i.e. any argument going beyond those submitted by the Opponent. As detailed hereinbefore, the Board taking into consideration the Opponent's objection to auxiliary request 3 likewise cannot be regarded as an exceptional circumstance which would justify the admittance of these late filed requests, it being abundantly clear to the Patentee (and anybody having ordinary technical knowledge in the field) that the objections raised in the Opponent's statement of grounds of appeal (against claim 1 of auxiliary request 1) would identically apply to claim 1 of auxiliary request 3. These circumstances, implying the Opponent's arguments being taken into consideration (see also point 5 hereinabove), for the very same reasons do not warrant admittance of these auxiliary requests.

Finally, the Board considers that Article 13(2) RPBA 2020 gives the Board no discretion to admit late filed auxiliary requests when no exceptional circumstances justified with cogent reasons are present, regardless of these requests being or not prima facie allowable (which was however not discussed during oral proceedings and represents merely the Patentee's contention).