T 0428/23 20-03-2025

1. Main request, inventive step - Article 56 EPC

1.1 Claim 1

1.1.1 Disclosure of D16

It is undisputed that D16 discloses a fence structure (see paragraph [0002]) (feature 1.1),

comprising a plurality of transverse elements (30, 50, 70) arranged on one or more superimposed horizontal rows (see Figure 1) and supported by vertical uprights (posts) (10) (feature 1.2),

whereby said uprights (10) are constituted by first tubular metallic sections (see penultimate sentence of paragraph [0025]) with substantially rectilinear axis (see Figures 1 and 2) (feature 1.3),

wherein the first metallic sections (10) have upper heads with saddle-like working (see "post top aperture" (16)), i.e. delimiting a substantially U-shaped seat facing upward (see Figure 2) for the abutment of an end of at least one transverse element (30) or of a section of the latter (see Figure 1) (feature 1.5).

1.1.2 Distinguishing features and related technical problem

It is undisputed that the subject-matter of claim 1 differs from the embodiment of D16 based on an upright made of metal in feature 1.4 ("said first metallic sections are made of COR-TEN steel").

The respondent did not dispute that the technical effect of distinguishing feature 1.4 is that corrosion resistance increases. The associated objective technical problem to be considered is thus - as argued by the appellant - how to improve resistance to corrosion caused by weather agents.

1.1.3 Alleged lack of motivation in the closest prior art

The opposition division considered in the contested decision that the skilled person would not have arrived at the invention starting from D16 since this document did not provide any incentive to adapt or modify the fence disclosed therein to improve its corrosion resistance, in particular since this closest prior art teaches the use of various materials already having good corrosion resistance (see point II.20.4 of the contested decision).

The respondent agreed with this consideration and remained adamant that D16 did not provide any incentive to look for other materials, no reason being apparent for the skilled person to envisage a change of material. Any change of material was thus purely hindsight-driven.

This is not persuasive for the following reasons:

The problem-solution approach is based on what the

skilled person would do when looking for a solution to the objective technical problem, which is defined on the basis of the technical effect produced by the distinguishing features.

The closest prior art is the starting point for the analysis according to the problem-solution approach, but the skilled person starting from the embodiment of D16 based on an upright made of metal - which results in an objective technical problem only relating to improving corrosion resistance - is not prevented from looking for other materials just because this document discloses several alternative materials. The fact that some of these materials may exhibit good anti-corrosion properties is not an indication to the skilled person that they are the only materials to be used for the embodiments disclosed therein. In other words, D16 does not teach away from considering other materials.

It is a conceptual error to consider that the closest prior art must provide an incentive to modify the same in order to justify an absence of inventive step. The motivation to modify (if any) can also be - and usually is - found in the secondary teaching consulted by the skilled person when looking for a solution to the objective technical problem. Indeed, a teaching in the secondary document is usually the pointer which incites the person skilled in the art to apply the prior-art teaching disclosed in the secondary document in order to overcome the objective technical problem. Such a pointer or incentive is precisely what differentiates the obvious solution from a hindsight-based solution or the "would" from the "could". In the present case, the known anti-corrosive properties of the Corten-steel metal provide a motivation or pointer to use the material to improve corrosion resistance. There is thus no hindsight in the analysis, contrary to what has been argued by the respondent with reference to case law, which concerned, however, different factual circumstances.

1.1.4 Alleged technical prejudice against using Corten steel

The respondent argued that the appellant did not justify why the skilled person would not see the problems allegedly entailed in the use of Corten steel in D16.

This is not persuasive since the burden of proof lies with the party making the allegation in this respect. It was the respondent that had the obligation to show that a technical prejudice against the use of Corten steel in a fence upright like that of D16 existed before the priority date and that this would have dissuaded the skilled person from considering this material for this particular application.

The respondent put forward that it was part of the common general knowledge of the skilled person that the use of Corten steel entailed disadvantages in applications with water accumulation or in salty environments, as disclosed on page 5 of D32.

This is generally true, but it is not persuasive when considering in detail what the common general knowledge in this respect was when considering a construction as in D16.

The point "Disadvantages", bridging pages 4 and 5 of D32, discloses that the use of Corten steel in construction presents "several challenges". D32 does indeed disclose that "[i]f water is allowed to accumulate in pockets, those areas will experience higher corrosion rates, so provision for drainage must be made", but this statement is made in the context of applications in construction. As noted by the respondent during the oral proceedings, D32 cites in this respect two constructions that have been affected by such problems as illustrative examples, namely Hawaii's Aloha Stadium and the Omni Coliseum in Atlanta.

This common general knowledge with respect to the technical field of construction does not result in a generalised technical prejudice against all applications. Instead, it is restricted to the existence of reservations regarding the use of Corten steel in this particular field, namely in an application which implies certain dimensions and requirements for the elements involved. This does not mean that it was common general knowledge that any water accumulation or humidity concentration in an element differing from a construction element - e.g. a fence upright, as disclosed in D16 - rendered the application of Corten steel unsuitable for it. The same applies to the case of the disclosed disadvantages linked to a use in "salty environments", the fence of D16 furthermore not being disclosed as being intended for such environments.

The patent specification does not support the alleged technical prejudice either, since it contains no reference to any problems caused by water accumulation or humidity, let alone to any means of countering these alleged problems. It is true that the skilled person cannot look at the contested patent when considering what was obvious before the priority date, as argued by the respondent. However, in the absence of any evidence and without there even being any mention of alleged technical prejudice in the cited prior art, it is not convincing that the precise contribution of the invention was to be seen in overcoming such technical prejudice. Rather, the upright construction disclosed in the contested patent is actually analogous to that of D16. Both upright constructions consist of metallic tubular sections which are closed on all sides, whether this be by transverse elements penetrating the holes in the upright in a close manner (compare Figures 8 and 9 of the patent and Figures 1 and 5 of D16) or by a closing element on the top (compare "covers" (4) in the patent and "post cap" (12) in D16). The Board is not persuaded that such an upright construction would result in critical accumulations of water or humidity which would jeopardise the stability of the upright in an analogous manner to the case of the construction elements mentioned in D32, in particular in view of the closed structure of the upright once the fence is assembled. The argument about an increase in temperature due to friction caused by thermal dilatation, which would encourage corrosion, is merely speculative and not based on any disclosure in the patent. This effect would thus not be seen as encompassed by that original disclosure.

Consequently, the Board concludes that the skilled person had no technical prejudice against using Corten steel for an upright as disclosed in D16 since it has not been proven that it was common general knowledge that Corten steel was an unsuitable material for producing such an upright construction (on the contrary, it was used in comparable structures - see point 1.1.5 below, in particular the reference to D1, D2, D4 and D7).

1.1.5 Obviousness in view of common general knowledge

It is not disputed that the advantageous properties of Corten steel in relation to corrosion were part of the common general knowledge before the priority date of the contested patent.

The skilled person looking for a solution to the problem posed (how to improve the resistance of the metallic upright of D16 to corrosion caused by weather agents) would thus consider Corten steel as a possible metallic material for producing the uprights (10) of D16 in an obvious manner. This applies particularly since Corten steel has been used for all kinds of metallic elements, even including tubular elements comparable to the uprights (10) of D16 (see, in particular, the fence-like groyne sections disclosed in D7 - see column 7, lines 33 to 40), which counters the alleged technical prejudice related to producing tubular elements for a fence from this material.

The respondent argued that Corten steel was always disclosed in connection with particular constructions in the cited prior art and that isolating this material from the particular construction could only be carried out with hindsight.

This argument is not relevant since the Board finds that the use of Corten steel for producing the uprights (10) of D16 would be obvious on account of the common general knowledge of the skilled person about this material. Hence, it would not necessarily require a combination thereof with a particular piece of prior art. Nevertheless, it is worth noting that Corten steel is cited in a general manner in each of the cited patent documents as just another material in the list of possible materials, and it is thus not disclosed as being inextricably linked to any particular construction disclosed therein based on technical considerations (see, e.g., D1: column 4, lines 32 to 34; D2; D4: column 2, lines 12 to 16; D5: page 6, last paragraph; or D7: column 7, lines 33 to 40).

1.1.6 Conclusion

In view of the above, the subject-matter of claim 1 does not involve an inventive step with respect to the combination of D16 and the common general knowledge (Article 56 EPC).

1.2 Claim 3

The objections of the appellant against claim 3 were based on the use of document D15 as the closest prior art. The same objective technical problem and secondary sources of information for the skilled person were proposed as for the objections based on D16.

Document D15 discloses tubular uprights made from a metallic material ("posts" (1)) of an analogous construction to those of D16 (see Figures 3 and 7 disclosing the tubular construction and the provision of housing holes (8) receiving the transverse elements (3); see also column 1, lines 63 to 68).

It is undisputed that the only distinguishing feature is feature 1.4 ("first metallic sections are made of COR-TEN steel"), as in the case of D16.

Consequently, the same considerations as in point 1.1 above apply here, mutatis mutandis.

1.3 Claim 15

The object of claim 15 is an upright for obtaining a fence comprising a first tubular metallic section basically corresponding to the one defined in claim 1 or claim 3.

The objections of the appellant against claim 15 were based on the use of document D15 as the closest prior art. The same objective technical problem and secondary sources of information for the skilled person were proposed as for the objections against claim 3.

Therefore, the same considerations as explained in points 1.1 and 1.2 above apply here, mutatis mutandis.

2. Auxiliary request 4

The respondent requested that auxiliary request 4 be handled immediately after the main request if A1 and A2 were taken into consideration in the appeal proceedings.

This was not the case and, therefore, auxiliary request 4 is not to be discussed. In any case it would have to be assessed like the main request, since claim 1 of auxiliary request 4 corresponds to claim 3 of the main request (see point 1.2 above).

3. Auxiliary request 1, admittance of objections - Article 13(2) RPBA

3.1 Legal basis

It is undisputed that none of the appellant's objections against auxiliary request 1 raised during the oral proceedings before the board had been previously presented during the written phase of the proceedings.

They are thus amendments, the admittance of which is subject to the discretion of the Board under Article 13(2) RPBA. This provision specifies that such amendments shall, in principle, not be taken into account unless there are exceptional circumstances, which have been justified with cogent reasons by the party concerned.

3.2 Reasons for the late submission of the objections

The appellant argued that the oral proceedings before the Board constituted the first occasion on which auxiliary request 1 was discussed in substance and that there had been no earlier opportunity for it to respond to auxiliary request 1 since its letter dated 28 December 2023 had been filed for a different main purpose, namely to comment on other objections raised against the main request. Therefore, according to the appellant, it had not been possible to raise any objections against auxiliary request 1 before the oral proceedings and the objections raised at this stage should be admitted in order to respect the appellant's right to reply to the respondent's arguments.

This is not persuasive.

Auxiliary request 1 was submitted by the respondent on 6 October 2023 with its reply to the statement setting out the grounds of appeal. It was after receiving this reply that the appellant should have reacted, namely by raising its objections against this request already in the written appeal proceedings. It is noteworthy that the appellant actually submitted a letter on 28 December 2023, which included arguments relating to the main request, but which did not address auxiliary request 1 despite the appellant already being aware of this request at that point in time.

Furthermore, the Board explicitly stated in its communication under Article 15(1) RPBA that the appellant had not raised any objections against auxiliary request 1 (see point 12 of the communication), but the appellant did not react in this context either.

Therefore, the board cannot accept the argument about the appellant not being able to raise objections against auxiliary request 1 prior to the oral proceedings before the Board. The appellant could have replied to the respondent's arguments - which were explained in point 11.1 of the respondent's reply to the appeal - once it became aware of the respondent's submission. However, by not doing so until the latest possible moment in the appeal proceedings, the appellant itself has made its submissions subject to the strict requirements of Article 13(2) RPBA.

3.3 Prima facie relevance of the objections related to inventive step

The appellant argued that no technical advantage or solved problem was disclosed in the contested patent in relation to incorporated feature 1.11 ("said at least one ear or tab or tongue extends towards the outside of the respective upright"), let alone regarding improved corrosion resistance or easier assembly, as proposed by the respondent. According to the appellant, this implied that no inventive activity could be acknowledged in relation to this distinguishing feature.

This is not persuasive since the skilled person with a background in mechanics understands from the content of the patent (see, e.g., Figure 8 and paragraph [0056]) that the engagement of the "screw or bolt or rivet" (3f) is rendered easier by the location of the tab's through hole (3e) outside the tubular metallic section. This technical effect is self-explanatory for the skilled person in view of the figures of the patent.

The Board notes that this does not mean that the technical contribution of the invention would thus, "by definition", necessarily be obvious in view of that same common general knowledge. The skilled person looking at a particular disclosure can infer technical effects deriving from what they see in view of their technical background, which allows them to understand the technical implications behind the disclosed solution. However, this does not imply that they would necessarily have thought of this as a solution to a particular technical problem before having an opportunity to observe it for the first time.

As a second line of attack, the appellant argued that D15 disclosed a tab ("flap" (6)) suitable to be used as defined in claim 1, and that the skilled person would have contemplated in an obvious manner bending this tab (6) outwards instead of inwards (as disclosed in Figure 3) since this was a mere design choice in their hands when assembling the fence. This modification was allegedly a well-known solution for fixing pieces together more easily in the construction field and no inventive contribution could be seen in this respect. According to the appellant, D6 disclosed such folding of a flap ("flange" (56)) outwards of a closed structure to assemble a transverse element (see Figure 4).

This is not persuasive either, since D6 relates to a completely different construction, namely a flange (54) connected to a post member (18) of a guard rail. No tubular metallic structure comprising holes for insertion of the transverse elements is disclosed in D6, from the edge of which the alleged "flap" would extend as in D15 (see Figure 3). The skilled person would thus not find any teaching in D6 that incited them to fold the flap (6) of D15 outwards instead of inwards.

Furthermore, the alleged existence of common general knowledge of the skilled person about "a well-known solution for fixing pieces together more easily in the construction field" has not been substantiated by the appellant.

Consequently, the raised objections related to inventive step are not prima facie relevant to the outcome of the proceedings.

3.4 Prima facie relevance of the objections related to added subject-matter and sufficiency of the disclosure

3.4.1 The appellant argued that the combination of features defined in claim 1 was not originally disclosed since the figures of the originally filed application related to different embodiments, which could not be combined at will to justify a basis for the subject-matter of claim 1. Moreover, according to the appellant, Figure 15 did not disclose an outwardly extending tab which was connected with the upper transverse element, the reference number (3f) indicating only some undefined "locking means".

This is not, prima facie, persuasive.

Inserted features 1.6 to 1.10 result from the incorporation into claim 1 of the subject-matter of originally filed claims 5 (feature 1.6), 9 (features 1.7, 1.8 and 1.9) and 13 (feature 1.10), the combination of these features thus being originally disclosed. Concerning incorporated feature 1.11, Figure 15 of the originally filed application (reproduced below) discloses the screws (3f) - thus, not just some "undefined locking means" -, which are explicitly disclosed as being intended to be engaged in the third through hole (3e) of the tabs (3d), be it in a horizontal or vertical direction (see paragraphs [0054], [0056], [0061] and lines 43 and 44 on page 5 of the A1 publication of the application). The skilled person understands from Figure 15 (and the corresponding description) that the screws (3f) connected to the upper transverse element (2) must be arranged vertically - according to one of the two possibilities explicitly disclosed - in view of the disclosed position of the screw (3f) indicated by the arrow linked to the corresponding reference number in the figure.

FORMULA/TABLE/GRAPHIC

Feature 1.11 ("said at least one ear or tab or tongue extends towards the outside of the respective upright") thus has a basis in the originally filed application both for the case of the "ear or tab or tongue" projectingly extending from a portion of the delimitation edge of the at least one housing hole and for the case of the "ear or tab or tongue" projectingly extending from the delimitation edge of the saddle-like end or upper head. The skilled person reading the originally filed application would have no reason to consider that this feature was inextricably linked to other features (not specified by the appellant) of the particular embodiment in view of their technical function. On the contrary, the skilled person would understand that this type of fixation means was intended to be combined with the invention defined in its more general terms (see the originally filed claims, from which the vast majority of the subject-matter of claim 1 stems), in which - see claim 13 as filed - the subject-matter was already generalised towards at least one ear or tab or tongue being "projectingly extended".

3.4.2 Concerning sufficiency of disclosure, the appellant put forward that the skilled person would not know how to connect the vertically extending tab of Figure 16 of the contested patent to the upper transverse element, and that, even if the skilled person assumed that the tab of Figure 16 had to be bent somehow, the patent contained no information about how this bending should take place and to which extent.

This is not persuasive since the contested patent makes it abundantly clear that the "ears or tabs or tongues" (3d) are bent before assembly of the fence in order to achieve the right orientation allowing the "screw or bolt or rivet" (3f) to penetrate their third through hole (3e) and the corresponding transverse element (2) (see paragraphs [0059] and [0065]). Figure 16 corresponds to "an enlarged-scale view of an upright for the fence of fig. 15" (see column 3, lines 8 and 9) and the skilled person thus understands that, since this figure shows a tab (3d) extending vertically upwards whereas Figure 15 shows (implicitly; see point 3.4.1 above) the tab extending horizontally, the tab (3d) of Figure 16 must be bent as explicitly described in the patent to reach the required position. The skilled person with an average knowledge of mechanics needs no further information to reproduce the disclosed arrangement.

3.4.3 In view of the above, neither the objection based on the grounds of extension of subject-matter (Article 123(2) EPC), nor the objection based on the grounds of sufficiency of disclosure (Article 83 EPC) is prima facie relevant.

3.5 Since the objections were filed late without any reason justifying this and are furthermore not prima facie relevant, they are not admitted into the proceedings under Article 13(2) RPBA.

4. Adapted description

The appellant had no objections as regards the adapted description filed with respect to auxiliary request 1.

The Board sees no reason to object either.

5. Article 101(3)(a) EPC

Since, taking into account the amendments made by the respondent to auxiliary request 1, the requirements of the EPC are met, the patent can be maintained as amended according to Article 101(3)(a) EPC.